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# Source code for tecplot.plot.linemap

    from builtins import super, int

    import ctypes

    from collections import namedtuple
    from textwrap import dedent

    from ..tecutil import (_tecutil, Index, IndexRange, IndexSet, color_spec,
                           flatten_args, sv)
    from ..constant import *
    from ..exception import *
    from .. import session
    from .scatter import GeometrySymbol, TextSymbol, Symbol

    class LinemapStyle(session.Style):
        def __init__(self, linemap, *svargs):
            kw = dict(uniqueid=linemap.plot.frame.uid, offset1=linemap.index,
                      multiset=True)
            super().__init__(linemap._sv, *svargs, **kw)

        def __eq__(self, that):
            return isinstance(that, type(self)) and (self.linemap == that.linemap)

        def __ne__(self, that):
            return not (self == that)

    class LinemapBars(LinemapStyle):
        """Bar chart style control.

        A bar chart is an XY Line plot that uses vertical or horizontal bars placed
        along an axis to represent data points. Changing the function dependency of
        the linemap with `XYLinemap.function_dependency` controls the direction of
        the bars. By default, all mappings use :math:`y = f(x)` and appear as
        vertical bar charts. Setting *y* to be the independent variable will cause
        the bars to be horizontal.

        .. code-block:: python
            :emphasize-lines: 12,16-21

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()
            plot.show_bars = True

            lmap = plot.linemap(0)

            bars = lmap.bars
            bars.show = True
            bars.size = 0.6*(100 / dataset.zone(0).num_points)
            bars.fill_color = Color.Red
            bars.line_color = Color.Red
            bars.line_thickness = 0.01

            tp.export.save_png('linemap_bars.png', 600)

        ..  figure:: /_static/images/linemap_bars.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.BARCHARTS)

        @property
        def show(self):
            """Display bars on the plot for this :ref:`Linemap`.

            :type: `bool`

            The parent plot object must have bars enabled as well::

                >>> plot.show_bars = True
                >>> plot.linemap(0).bars.show = True
            """
            return self._get_style(bool, sv.SHOW)

        @show.setter
        def show(self, value):
            self._set_style(bool(value), sv.SHOW)

        @property
        def size(self):
            """Width of the bars.

            :type: `float` (percentange of `Frame` width)

            Example usage::

                >>> plot.linemap(0).bars.size = 0.10
            """
            return self._get_style(float, sv.SIZE)

        @size.setter
        def size(self, value):
            self._set_style(float(value), sv.SIZE)

        @property
        def fill_mode(self):
            """fill mode for the bars.

            :type: `FillMode`

            Possible values: `FillMode.UseSpecificColor`, `FillMode.UseLineColor`,
                `FillMode.UseBackgroundColor` or `FillMode.None_`.

            Example usage::

                >>> from tecplot.constant import FillMode
                >>> bars = plot.linemap(0).bars
                >>> bars.fill_mode = FillMode.UseBackgroundColor
            """
            return self._get_style(FillMode, sv.FILLMODE)

        @fill_mode.setter
        def fill_mode(self, value):
            self._set_style(FillMode(value), sv.FILLMODE)

        @property
        def fill_color(self):
            """Fill color of the bars.

            :type: `Color` or `ContourGroup`.

            The ``fill_mode`` attribute must be set to
            `FillMode.UseSpecificColor`::

                >>> from tecplot.constant import Color, FillMode
                >>> bars = plot.linemap(0).bars
                >>> bars.fill_mode = FillMode.UseSpecificColor
                >>> bars.fill_color = Color.Red
            """
            return color_spec(self._get_style(Color, sv.FILLCOLOR),
                              self.linemap.plot)

        @fill_color.setter
        def fill_color(self, value):
            self._set_style(color_spec(value), sv.FILLCOLOR)

        @property
        def line_color(self):
            """Edge line color of the bars.

            :type: `Color`

            Example usage::

                >>> from tecplot.constant import Color
                >>> plot.linemap(0).bars.line_color = Color.Red
            """
            return self._get_style(Color, sv.COLOR)

        @line_color.setter
        def line_color(self, value):
            self._set_style(Color(value), sv.COLOR)

        @property
        def line_thickness(self):
            """Edge line thickness of the bars.

            :type: `float`

            Example usage::

                >>> plot.linemap(0).bars.line_thickness = 0.1
            """
            return self._get_style(float, sv.LINETHICKNESS)

        @line_thickness.setter
        def line_thickness(self, value):
            self._set_style(float(value), sv.LINETHICKNESS)

    class LinemapCurve(LinemapStyle):
        """Curve-fitting of the line.

        This class controls how the line is to be drawn between data points. By
        default, the `CurveType.LineSeg` option is used and straight lines are
        used. Setting `curve_type` to a fit type or spline type will replace the
        line segments with a smooth curve:

        .. code-block:: python
            :emphasize-lines: 33,35-37,39-42,44-46

            import numpy as np
            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, CurveType

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)
            dataset.add_variable('Weight')

            # convert error to weighting to be used for fitting below
            # This converts the error to  (1 / error)
            # and normalizes to the range [1,100]
            zone = dataset.zone('ZONE 1')
            err1 = zone.values('Error 1')
            wvar = zone.values('Weight')
            err = err1.as_numpy_array()
            sigma = 1. / err
            dsigma = sigma.max() - sigma.min()
            sigma = (99 * (sigma - sigma.min()) / dsigma) + 1
            wvar[:] = sigma

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            xvar = dataset.variable(0)
            for lmap,var in zip(plot.linemaps(),list(dataset.variables())[1:4]):
                lmap.x_variable = xvar
                lmap.y_variable = var
                lmap.show = True

            curves = [lmap.curve for lmap in plot.linemaps()]

            curves[0].curve_type = CurveType.PolynomialFit
            curves[0].num_points = 1000
            curves[0].polynomial_order = 10

            curves[1].curve_type = CurveType.PowerFit
            curves[1].use_fit_range = True
            curves[1].fit_range = 4,8
            curves[1].weight_variable = dataset.variable('Weight')
            curves[1].use_weight_variable = True

            curves[2].curve_type = CurveType.Spline
            curves[2].clamp_spline = True
            curves[2].spline_derivative_at_ends = 0,0

            tp.export.save_png('linemap_curve.png', 600)

        ..  figure:: /_static/images/linemap_curve.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.CURVES)

        _Limits = namedtuple('Limits', ['min', 'max'])
        _Limits.__new__.__defaults__ = (None, None)

        _Derivatives = namedtuple('Derivatives', ['start', 'end'])
        _Derivatives.__new__.__defaults__ = (None, None)

        @property
        def curve_type(self):
            """Type of curve to draw or fit.

            :type: `CurveType`

            Possible values: `LineSeg`, `PolynomialFit`, `EToRFit`, `PowerFit`,
            `Spline`, `ParaSpline`.

            `CurveType.LineSeg` (line segment, no curve-fit)
                A series of linear segments connect adjacent data points. In XY
                Line plots, these will be line segments.
            `CurveType.PolynomialFit`
                A polynomial of order `LinemapCurve.polynomial_order` is fit to the
                data points where :math:`1 <= N <= 10`. :math:`N = 1` is a
                straight-line fit.
            `CurveType.EToRFit` (exponential curve-fit)
                An exponential curve-fit that finds the best curve of the form
                :math:`Y = e^{b\cdot X+c}` which is equivalent to :math:`Y = a\cdot
                e^{b\cdot X}`, where :math:`a = e^c`. To use this curve type,
                *Y*-values for this variable must be all positive or all negative.
                If the function dependency is set to :math:`X = f(Y)` all
                *X*-values must be all positive or all negative.
            `CurveType.PowerFit`
                A power curve fit that finds the best curve of the form :math:`Y =
                e^{b \cdot \ln X + c}` which is equivalent to :math:`Y = a\cdot X^b`
                , where :math:`a = e^c`. To use this curve type, *Y*-values for this
                variable must be all positive or all negative; *X*-values must be
                all positive. If the function dependency is set to :math:`X =
                f(Y)`, *X*-values must be all positive or all negative, and the
                *Y*-values must all be positive.
            `CurveType.Spline`
                A smooth curve is generated that goes through every point. The
                spline is drawn through the data points after sorting the points
                into increasing values of the independent variable, resulting in a
                single-valued function of the independent variable. The spline may
                be clamped or free. With a clamped spline, you supply the
                derivative of the function at each end point; with a non-clamped
                (natural or free) spline, these derivatives are determined for you.
                In xy-line plots, specifying the derivative gives you control over
                the initial and final slopes of the curve.
            `CurveType.ParaSpline` (parametric spline)
                Creates a smooth curve as with a spline, except the assumption is
                that both variables are functions of the index of the data points.
                For example in xy-line plot, `ParaSpline` fits :math:`x = f(i)` and
                :math:`y=g(i)` where :math:`f()` and :math:`g()` are both smooth.
                No additional sorting of the points is performed. This spline may
                result in a multi-valued function of either or both axis variables.

            Example usage::

                >>> from tecplot.constant import CurveType
                >>> plot.linemap(0).curve.curve_type = CurveType.PolynomialFit
            """
            return self._get_style(CurveType, sv.CURVETYPE)

        @curve_type.setter
        def curve_type(self, value):
            self._set_style(CurveType(value), sv.CURVETYPE)

        @property
        def polynomial_order(self):
            """Order of the fit when set to polynomial.

            :type: `integer <int>` (1 to 10)

            A value of 1 will fit the data to a straight line. Example usage::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.polynomial_order = 4
            """
            return self._get_style(int, sv.POLYORDER)

        @polynomial_order.setter
        def polynomial_order(self, value):
            self._set_style(int(value), sv.POLYORDER)

        @property
        def num_points(self):
            """Number of points to use when drawing a fitted curve.

            :type: `integer <int>`

            Example usage::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.num_points = 100
            """
            return self._get_style(int, sv.NUMPTS)

        @num_points.setter
        def num_points(self, value):
            self._set_style(int(value), sv.NUMPTS)

        @property
        def use_weight_variable(self):
            """Use the specified variable for curve-fit weighting.

            :type: `boolean <bool>`

            Example usage::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.use_weight_variable = True
                >>> curve.weight_variable_index = 3
            """
            return self._get_style(bool, sv.USEWEIGHTVAR)

        @use_weight_variable.setter
        def use_weight_variable(self, value):
            self._set_style(bool(value), sv.USEWEIGHTVAR)

        @property
        def weight_variable_index(self):
            """Zero-based index of the variable to use for curve-fit weighting.

            :type: `integer <int>`

            The ``use_weight_variable`` attribute must be set to `True`::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.use_weight_variable = True
                >>> curve.weight_variable_index = 3
            """
            return self._get_style(Index, sv.WEIGHTVAR)

        @weight_variable_index.setter
        def weight_variable_index(self, index):
            self._set_style(Index(index), sv.WEIGHTVAR)

        @property
        def weight_variable(self):
            """Variable to use for curve-fit weighting.

            :type: `Variable`

            Example usage::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.use_weight_variable = True
                >>> curve.weight_variable = dataset.variable('P')
            """
            idx = self.weight_variable_index
            return self.linemap.plot.frame.dataset.variable(idx)

        @weight_variable.setter
        def weight_variable(self, variable):
            self.weight_variable_index = variable.index

        @property
        def use_fit_range(self):
            """Limit the fit to the ``fit_range`` specified.

            :type: `boolean <bool>`

            Example usage::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.use_fit_range = True
                >>> curve.fit_range = 5, 10
            """
            return self._get_style(bool, sv.USEINDVARRANGE)

        @use_fit_range.setter
        def use_fit_range(self, value):
            self._set_style(bool(value), sv.USEINDVARRANGE)

        @property
        def fit_range(self):
            """The range to fit and display a fitted curve.

            :type: 2-`tuple` of `floats <float>`

            Example showing how to set the limits of a polynomial fit to [5,10].
            The ``use_fit_range`` attribute must be set to `True`::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.PolynomialFit
                >>> curve.use_fit_range = True
                >>> curve.fit_range = 5, 10
            """
            vmin = self._get_style(float, sv.INDVARMIN)
            vmax = self._get_style(float, sv.INDVARMAX)
            return LinemapCurve._Limits(vmin, vmax)

        @fit_range.setter
        def fit_range(self, *limits):
            vmin, vmax = LinemapCurve._Limits(*flatten_args(*limits))
            if __debug__:
                if vmax is None or vmin is None:
                    err = 'fit_range must be a tuple: (min,max)'
                    raise TecplotLogicError(err)
            self._set_style(float(vmin), sv.INDVARMIN)
            self._set_style(float(vmax), sv.INDVARMAX)

        @property
        def clamp_spline(self):
            """Enable derivative clamping for spline fits.

            :type: `boolean <bool>`

            Example showing how to set the derivative at the limits of a spline
            curve to zero::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.Spline
                >>> curve.clamp_spline = True
                >>> curve.spline_derivative_at_ends = 0, 0
            """
            return self._get_style(bool, sv.CLAMPSPLINE)

        @clamp_spline.setter
        def clamp_spline(self, value):
            self._set_style(bool(value), sv.CLAMPSPLINE)

        @property
        def spline_derivative_at_ends(self):
            """Clamp the derivative of the spline fit at the edges of the range.

            :type: 2-`tuple` of `floats <float>`

            Example showing how to set the derivative at the limits of a spline
            curve to zero. Notice the ``clamp_spline`` attribute must be set to
            `True`::

                >>> from tecplot.constant import CurveType
                >>> curve = plot.linemap(0).curve
                >>> curve.curve_type = CurveType.Spline
                >>> curve.clamp_spline = True
                >>> curve.spline_derivative_at_ends = 0, 0
            """
            dstart = self._get_style(float, sv.SPLINEDERIVATIVEATSTART)
            dend = self._get_style(float, sv.SPLINEDERIVATIVEATEND)
            return LinemapCurve._Derivatives(dstart, dend)

        @spline_derivative_at_ends.setter
        def spline_derivative_at_ends(self, *values):
            dstart, dend = LinemapCurve._Derivatives(*flatten_args(*values))
            if __debug__:
                if dend is None or dstart is None:
                    err = dedent('''\
                        spline_derivative_at_ends must be a tuple:
                        (deriv_at_start, deriv_at_end)''')
                    raise TecplotLogicError(err)
            self._set_style(float(dstart), sv.SPLINEDERIVATIVEATSTART)
            self._set_style(float(dend), sv.SPLINEDERIVATIVEATEND)

    class LinemapErrorBars(LinemapStyle):
        """Error bar style and variable assignment control.

        A single `XYLinemap` holds a single `Variable` assignment for error bars.
        Therefore, if you wish to have separate error bars for *x* and *y*, two
        linemaps are required:

        .. code-block:: python
            :emphasize-lines: 30-34,36-40,43

            from math import sqrt
            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color, ErrorBar

            # setup dataset
            frame = tp.active_frame()
            ds = frame.create_dataset('Dataset')
            for v in ['x', 'y', 'xerr', 'yerr']:
                ds.add_variable(v)
            zone = ds.add_ordered_zone('Zone', 5)

            # create some data (x, y)
            zone.values('x')[:] = [0,1,2,3,4]
            zone.values('y')[:] = [1,2,4,8,10]

            # error in x is a constant
            zone.values('xerr')[:] = [0.2]*5

            # error in y is the square-root of the value
            zone.values('yerr')[:] = [sqrt(y) for y in zone.values('y')[:]]

            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            plot.delete_linemaps()
            xerr_lmap = plot.add_linemap('xerr', zone, ds.variable('x'),
                                         ds.variable('y'))
            yerr_lmap = plot.add_linemap('yerr', zone, ds.variable('x'),
                                         ds.variable('y'))

            xerr_lmap.error_bars.variable = ds.variable('xerr')
            xerr_lmap.error_bars.bar_type = ErrorBar.Horz
            xerr_lmap.error_bars.color = Color.Blue
            xerr_lmap.error_bars.line_thickness = 0.8
            xerr_lmap.error_bars.show = True

            yerr_lmap.error_bars.variable = ds.variable('yerr')
            yerr_lmap.error_bars.bar_type = ErrorBar.Vert
            yerr_lmap.error_bars.color = Color.Blue
            yerr_lmap.error_bars.line_thickness = 0.8
            yerr_lmap.error_bars.show = True

            plot.show_lines = False
            plot.show_error_bars = True

            plot.view.fit()

            tp.export.save_png('linemap_error_bars.png', 600)

        ..  figure:: /_static/images/linemap_error_bars.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.ERRORBARS)

        @property
        def show(self):
            """Display error bars on the plot for this :ref:`Linemap`.

            :type: `bool`

            The parent plot object must have error bars enables as well which will
            require a variable to be set::

                >>> plot.linemap(0).error_bars.variable = dataset.variable('E')
                >>> plot.show_error_bars = True
                >>> plot.linemap(0).error_bars.show = True
            """
            return self._get_style(bool, sv.SHOW)

        @show.setter
        def show(self, value):
            self._set_style(bool(value), sv.SHOW)

        @property
        def bar_type(self):
            """Style of the error bar to draw.

            :type: `ErrorBar`

            Possible values: `Up`, `Down`, `Left <ErrorBar.Left>`, `Right
            <ErrorBar.Right>`, `Horz`, `Vert`, `Cross`.

            Example usage::

                >>> from tecplot.constant import ErrorBar
                >>> plot.linemap(0).bar_type = ErrorBar.Cross
            """
            return self._get_style(ErrorBar, sv.BARTYPE)

        @bar_type.setter
        def bar_type(self, value):
            self._set_style(ErrorBar(value), sv.BARTYPE)

        @property
        def color(self):
            """`Color` of the error bars.

            :type: `Color`

            Example usage::

                >>> from tecplot.constant import Color
                >>> plot.linemap(0).color = Color.Red
            """
            return self._get_style(Color, sv.COLOR)

        @color.setter
        def color(self, value):
            self._set_style(Color(value), sv.COLOR)

        @property
        def endcap_size(self):
            """Length of the endcaps of the error bars.

            :type: `float`

            Example usage::

                >>> plot.linemap(0).endcap_size = 2.5
            """
            return self._get_style(float, sv.SIZE)

        @endcap_size.setter
        def endcap_size(self, value):
            self._set_style(float(value), sv.SIZE)

        @property
        def line_thickness(self):
            """Width of the error bar lines.

            :type: `float`

            Example usage::

                >>> plot.linemap(0).line_thickness = 0.8
            """
            return self._get_style(float, sv.LINETHICKNESS)

        @line_thickness.setter
        def line_thickness(self, value):
            self._set_style(float(value), sv.LINETHICKNESS)

        @property
        def step_mode(self):
            """Space the error bars by index or frame height.

            :type: `StepMode`

            This example will make sure all error bars are no closer than 10% of the
            frame height to each other::

                >>> from tecplot.constant import StepMode
                >>> ebars = plot.linemap(0).error_bars
                >>> ebars.step_mode = StepMode.ByFrameUnits
                >>> ebars.step = 10
            """
            return self._get_style(StepMode, sv.SKIPMODE)

        @step_mode.setter
        def step_mode(self, value):
            self._set_style(StepMode(value), sv.SKIPMODE)

        @property
        def step(self):
            """Space between points to show error bars.

            :type: `float`

            The step is specified either as a percentage of the frame height or
            as a number of indices to skip depending on the value of
            `LinemapErrorBars.step_mode`. This example will add error
            bars to every third point::

                >>> plot.linemap(0).error_bars.step = 3
            """
            return self._get_style(float, sv.SKIPPING)

        @step.setter
        def step(self, value):
            if __debug__:
                if value < 0:
                    raise TecplotLogicError('step must be >= 0')
            self._set_style(float(value), sv.SKIPPING)

        @property
        def variable_index(self):
            """Zero-based variable index to use for error bar sizes.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).error_bars.variable_index = 3
            """
            return self._get_style(Index, sv.VAR)

        @variable_index.setter
        def variable_index(self, index):
            self._set_style(Index(index), sv.VAR)

        @property
        def variable(self):
            """`Variable` to use for error bar sizes.

            :type: `Variable`

            Example usage::

                >>> ebars = plot.linemap(0).error_bars
                >>> ebars.variable = dataset.variable('Err')
            """
            return self.linemap.plot.frame.dataset.variable(self.variable_index)

        @variable.setter
        def variable(self, variable):
            self.variable_index = variable.index

    class LinemapIndices(LinemapStyle):
        """Ordering and spacing of points to be drawn.

        Each mapping can show either *I*, *J*, or *K*-varying families of lines. By
        default, the *I*-varying family of lines are displayed. You can also choose
        which members of the family are drawn (and using which data points), by
        specifying index ranges for each of *I*, *J*, and *K*. The index range for
        the varying index says which points to include in each line, and the index
        ranges for the other indices determine which lines in the family to
        include.

        .. code-block:: python
            :emphasize-lines: 15-16

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, IJKLines

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            for lmap in list(plot.linemaps())[:3]:
                lmap.show = True
                lmap.indices.varying_index = IJKLines.I
                lmap.indices.i_range = 0,0,3

            # save image to file
            tp.export.save_png('linemap_indices.png', 600)

        ..  figure:: /_static/images/linemap_indices.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.INDICES)

        @property
        def varying_index(self):
            """Family of lines to be drawn.

            :type: `IJKLines`

            This is the order which varies along the lines drawn. *K*-varying is
            only available if the mapping is using an *IJK*-ordered zone::

                >>> from tecplot.constant import IJKLines
                >>> plot.linemap(0).indices.varying_index = IJKLines.J
            """
            return self._get_style(IJKLines, sv.IJKLINES)

        @varying_index.setter
        def varying_index(self, index):
            self._set_style(IJKLines(index), sv.IJKLINES)

        @property
        def i_range(self):
            """`IndexRange` for the *I* dimension of ordered data.

            :type: `tuple` of `integers <int>` (min, max, step)

            This example shows ``I``-lines at ``i = [0, 2, 4, 6, 8, 10]``::

                >>> plot.linemap(0).indices.i_range = 0, 10, 2
            """
            return self._get_style(IndexRange, sv.IRANGE)

        @i_range.setter
        def i_range(self, values):
            self._set_style(IndexRange(*values), sv.IRANGE)

        @property
        def j_range(self):
            """`IndexRange` for the *J* dimension of ordered data.

            :type: `tuple` of `integers <int>` (min, max, step)

            This example shows all ``J``-lines starting with ``j = 10`` up to the
            maximum ``J``-line of the associated `Zone <data_access>`::

                >>> plot.linemap(0).indices.j_range = 10, None, 1
            """
            return self._get_style(IndexRange, sv.JRANGE)

        @j_range.setter
        def j_range(self, values):
            self._set_style(IndexRange(*values), sv.JRANGE)

        @property
        def k_range(self):
            """`IndexRange` for the *K* dimension of ordered data.

            :type: `tuple` of `integers <int>` (min, max, step)

            This example shows all ``K``-lines starting with the first up to 5
            from the last ``K``-line of the associated `Zone <data_access>`::

                >>> plot.linemap(0).indices.k_range = None, -5
            """
            return self._get_style(IndexRange, sv.KRANGE)

        @k_range.setter
        def k_range(self, values):
            self._set_style(IndexRange(*values), sv.KRANGE)

    class LinemapLine(LinemapStyle):
        """Style control for the line to be drawn.

        This controls the style of the lines plotted for a given `XYLinemap`.

        .. code-block:: python
            :emphasize-lines: 15-19

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color, LinePattern

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            lmap = plot.linemap(0)

            line = lmap.line
            line.color = Color.Blue
            line.line_thickness = 1
            line.line_pattern = LinePattern.LongDash
            line.pattern_length = 2

            # save image to file
            tp.export.save_png('linemap_line.png', 600)

        ..  figure:: /_static/images/linemap_line.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.LINES)

        @property
        def show(self):
            """Display this point-to-point line on the plot.

            :type: `bool`

            Example usage::

                >>> plot.linemap(0).line.show = True
            """
            return self._get_style(bool, sv.SHOW)

        @show.setter
        def show(self, value):
            self._set_style(bool(value), sv.SHOW)

        @property
        def color(self):
            """`Color` of the line to be drawn.

            :type: `Color`

            Example usage::

                >>> from tecplot.constant import Color
                >>> plot.linemap(0).line.color = Color.Blue
            """
            return self._get_style(Color, sv.COLOR)

        @color.setter
        def color(self, value):
            self._set_style(Color(value), sv.COLOR)

        @property
        def line_thickness(self):
            """Width of the line to be drawn.

            :type: `float`

            Example usage::

                >>> plot.linemap(0).line.line_thickness = 0.5
            """
            return self._get_style(float, sv.LINETHICKNESS)

        @line_thickness.setter
        def line_thickness(self, value):
            self._set_style(float(value), sv.LINETHICKNESS)

        @property
        def line_pattern(self):
            """Pattern style of the line to be drawn.

            :type: `LinePattern`

            Possible values: `Solid <LinePattern.Solid>`, `Dashed`, `DashDot`,
            `Dotted`, `LongDash`, `DashDotDot`.

            Example usage::

                >>> from tecplot.constant import LinePattern
                >>> lmap = plot.linemap(0)
                >>> lmap.line.line_pattern = LinePattern.LongDash
            """
            return self._get_style(LinePattern, sv.LINEPATTERN)

        @line_pattern.setter
        def line_pattern(self, value):
            self._set_style(LinePattern(value), sv.LINEPATTERN)

        @property
        def pattern_length(self):
            """Segment length of the repeated line pattern.

            :type: `float`

            Example usage::

                >>> from tecplot.constant import LinePattern
                >>> lmap = plot.linemap(0)
                >>> lmap.line.line_pattern = LinePattern.LongDash
                >>> lmap.line.pattern_length = 3.5
            """
            return self._get_style(float, sv.PATTERNLENGTH)

        @pattern_length.setter
        def pattern_length(self, value):
            self._set_style(float(value), sv.PATTERNLENGTH)

    class LinemapSymbols(LinemapStyle):
        """Style control for markers placed along lines.

        This class allows the user to set the style of the symbols to be shown
        including setting a geometric shape, text character, line and fill
        colors and spacing. The plot-level ``show_symbols`` attribute must be
        enabled to show symbols in any specific linemap within the plot:

        .. code-block:: python
            :emphasize-lines: 12,15-20

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color, FillMode

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()
            plot.show_symbols = True

            for lmap in list(plot.linemaps())[:3]:
                lmap.symbols.show = True
                lmap.symbols.size = 2.5
                lmap.symbols.color = Color.Blue
                lmap.symbols.line_thickness = 0.4
                lmap.symbols.fill_mode = FillMode.UseSpecificColor
                lmap.symbols.fill_color = Color.Azure

            # save image to file
            tp.export.save_png('linemap_symbols.png', 600)

        ..  figure:: /_static/images/linemap_symbols.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, linemap):
            self.linemap = linemap
            super().__init__(linemap, sv.SYMBOLS)

        @property
        def show(self):
            """Display symbols along the lines to be drawn.

            :type: `bool`

            The parent plot object must have symbols enabled as well::

                >>> plot.show_symbols = True
                >>> plot.linemap(0).symbols.show = True
            """
            return self._get_style(bool, sv.SHOW)

        @show.setter
        def show(self, value):
            self._set_style(bool(value), sv.SHOW)

        @property
        def symbol_type(self):
            """The `SymbolType` to use for this linemap.

            :type: `SymbolType`

            Possible values are: `SymbolType.Geometry`, `SymbolType.Text`.

            This sets the active symbol type. Use LinemapSymbols.symbol` to access
            the symbol::

                >>> from tecplot.constant import SymbolType
                >>> linemap = plot.linemap(0)
                >>> linemap.symbols.symbol_type = SymbolType.Text
                >>> symbol = linemap.symbols.symbol(SymbolType.Text)
                >>> symbol.text = 'a'
            """
            return Symbol(self)._symbol_type

        @symbol_type.setter
        def symbol_type(self, value):
            Symbol(self)._symbol_type = value

        def symbol(self, symbol_type=None):
            """Returns a linemap symbol style object.

            Parameters:
                symbol_type (`SymbolType`, optional): The type of symbol to return.
                    By default, this will return the active symbol type which is
                    obtained from `LinemapSymbols.symbol_type`.

            Returns: `TextSymbol` or `GeometrySymbol`

            Example usage::

                >>> from tecplot.constant import SymbolType
                >>> plot.linemap(0).symbols.symbol_type = SymbolType.Text
                >>> symbol = plot.linemap(0).symbols.symbol()
                >>> symbol.text = 'a'
            """
            _dispatch = {
                SymbolType.Text: TextSymbol,
                SymbolType.Geometry: GeometrySymbol}
            return _dispatch[symbol_type or self.symbol_type](self)

        @property
        def step_mode(self):
            """Space the symbols by index or frame height.

            :type: `StepMode`

            This example will make sure all symbols are no closer than 10% of the
            frame height to each other::

                >>> from tecplot.constant import StepMode
                >>> sym = plot.linemap(0).symbols
                >>> sym.step_mode = StepMode.ByFrameUnits
                >>> sym.step = 10
            """
            return self._get_style(StepMode, sv.SKIPMODE)

        @step_mode.setter
        def step_mode(self, value):
            self._set_style(StepMode(value), sv.SKIPMODE)

        @property
        def step(self):
            """Space between symbols to be shown.

            :type: `float`

            The step is specified either as a percentage of the frame height or
            as a number of indices to skip depending on the value of
            `LinemapSymbols.step_mode`. This example will add symbols
            to every third point::

                >>> plot.linemap(0).symbols.step = 3
            """
            return self._get_style(float, sv.SKIPPING)

        @step.setter
        def step(self, value):
            if __debug__:
                if value < 0:
                    raise TecplotLogicError('step must be >= 0')
            self._set_style(float(value), sv.SKIPPING)

        @property
        def size(self):
            """Size of the symbols to draw.

            :type: `float`

            Example usage::

                >>> plot.linemap(0).symbols.size = 3.5
            """
            return self._get_style(float, sv.SIZE)

        @size.setter
        def size(self, value):
            self._set_style(float(value), sv.SIZE)

        @property
        def fill_mode(self):
            """The fill mode for the background.

            :type: `FillMode`

            Possible values: `FillMode.UseSpecificColor`, `FillMode.UseLineColor`,
                `FillMode.UseBackgroundColor` or `FillMode.None_`.

            Example usage::

                >>> from tecplot.constant import Color, FillMode
                >>> symbols = plot.linemap(0).symbols
                >>> symbols.fill_mode = FillMode.UseBackgroundColor
            """
            return self._get_style(FillMode, sv.FILLMODE)

        @fill_mode.setter
        def fill_mode(self, value):
            self._set_style(FillMode(value), sv.FILLMODE)

        @property
        def fill_color(self):
            """The fill or background color.

            :type: `Color`

            The ``fill_mode`` attribute must be set to
            `FillMode.UseSpecificColor`::

                >>> from tecplot.constant import Color, FillMode
                >>> symbols = plot.linemap(0).symbols
                >>> symbols.fill_mode = FillMode.UseSpecificColor
                >>> symbols.fill_color = Color.Yellow
            """
            return self._get_style(Color, sv.FILLCOLOR)

        @fill_color.setter
        def fill_color(self, value):
            self._set_style(Color(value), sv.FILLCOLOR)

        @property
        def color(self):
            """Edge or text `Color` of the drawn symbols.

            :type: `Color`

            Example usage::

                >>> from tecplot.constant import Color
                >>> plot.linemap(1).symbols.color = Color.Blue
            """
            return self._get_style(Color, sv.COLOR)

        @color.setter
        def color(self, value):
            self._set_style(Color(value), sv.COLOR)

        @property
        def line_thickness(self):
            """Width of the lines when drawing geometry symbols.

            :type: `float`

            Example usage::

                >>> from tecplot.constant import SymbolType
                >>> symbols = plot.linemap(0).symbols
                >>> symbols.symbol_type = SymbolType.Geometry
                >>> symbols.line_thickness = 0.8
            """
            return self._get_style(float, sv.LINETHICKNESS)

        @line_thickness.setter
        def line_thickness(self, value):
            self._set_style(float(value), sv.LINETHICKNESS)

    class Linemap(session.Style):
        """Style control for line plots.

        The Linemap layer controls how ordered or connected data is represented.
        This may be either a simple collection of line segments connecting all the
        data points, or a curve fitted to the original data::

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color, LinePattern, AxisTitleMode

            # load data from examples directory
            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            # get handle to the active frame and set plot type to XY Line
            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            # We will set the name, color and a few other properties
            # for the first three linemaps in the dataset.
            names = ['Seattle', 'Dallas', 'Miami']
            colors = [Color.Blue, Color.DeepRed, Color.Khaki]

            # loop over the linemaps, setting style for each
            for lmap,name,color in zip(plot.linemaps(),names,colors):
                lmap.show = True
                lmap.name = name # This will be used in the legend

                # Changing some line attributes
                line = lmap.line
                line.color = color
                line.line_thickness = 1
                line.line_pattern = LinePattern.LongDash
                line.pattern_length = 2

            # Set the y-axis label
            plot.axes.y_axis(0).title.title_mode = AxisTitleMode.UseText
            plot.axes.y_axis(0).title.text = 'Rainfall'

            # Turn on legend
            plot.legend.show = True

            # Adjust the axes limits to show all the data
            plot.view.fit()

            # save image to file
            tp.export.save_png('linemap.png', 600)

        ..  figure:: /_static/images/linemap.png
            :width: 300px
            :figwidth: 300px
        """
        def __init__(self, uid, plot):
            self.uid = uid
            self.plot = plot
            super().__init__(sv.LINEMAP, uniqueid=self.plot.frame.uid,
                             offset1=self.index, multiset=True)

        def __eq__(self, that):
            return self.uid == that.uid

        def __ne__(self, that):
            return not (self == that)

        @property
        def aux_data(self):
            """Auxiliary data for this linemap.

            Returns: `AuxData`

            This is the auxiliary data attached to the linemap. Such data is
            written to the layout file by default and can be retrieved later.
            Example usage::

                >>> from tecplot.constant import PlotType
                >>> plot = tp.active_frame().plot(PlotType.XYLine)
                >>> aux = plot.linemap(0).aux_data
                >>> aux['Result'] = '3.14159'
                >>> print(aux['Result'])
                3.14159
            """
            return session.AuxData(self.plot.frame, AuxDataObjectType.Linemap,
                                   self.index)

        @property
        def index(self):
            """Zero-based integer identifier for this :ref:`Linemap`.

            :type: `integer <int>`

            Example::

                >>> lmap = plot.linemap(1)
                >>> print(lmap.index)
                1
            """
            with self.plot.frame.activated():
                return Index(_tecutil.LineMapGetNumByUniqueID(self.uid) - 1)

        @property
        def name(self):
            """Name identifier of this :ref:`Linemap`.

            :type: `string <str>`

            Names are automatically assigned to each mapping. The nature of the
            name depends on the type of data used to create the mapping. If your
            data has only one dependent variable, the default is to use the zone
            name for the mapping. If your data has multiple dependent variables,
            then the default is to use the dependent variable name for the mapping.
            In either case each mapping is assigned a special name (``&ZN&`` or
            ``&DN&``) that is replaced with the zone or variable name when the name
            is displayed.

            Selecting variables in a 3D finite element zone may require significant
            time, since the variable must be loaded over the entire zone. XY and
            Polar line plots are best used with linear or ordered data, or with
            two-dimensional finite element data.

            Certain placeholder text will be replaced with values based on elements
            within the plot. By combining static text with these placeholders, you
            can construct a name in any format you like::

                >>> plot.linemap(2).name = 'Zone: &ZN&'

            The placeholders available are:

            Zone name (``&ZN&``)
                This will be replaced with the actual name of the zone assigned to
                that mapping.
            Zone number (``&Z#&``)
                This will be replaced with the actual number of the zone assigned
                to the mapping.
            Independent variable name (``&IV&``)
                This will be replaced with the actual name of the independent
                variable assigned to that mapping.
            Independent variable number (``&I#&``)
                This will be replaced with the actual number of the independent
                variable assigned to the mapping.
            Dependent variable name (``&DV&``)
                This will be replaced with the actual name of the dependent
                variable assigned to that mapping.
            Dependent variable number (``&D#&``)
                This will be replaced with the actual number of the dependent
                variable assigned to the mapping.
            Map number (``&M#&``)
                This will be replaced with the actual number of the mapping.
            X-Axis number (``&X#&``)
                This will be replaced with the actual number of the X-axis assigned
                to that mapping for XY Line plots. This option is not available
                for Polar Line plots.
            Y-Axis number (``&Y#&``)
                This will be replaced with the actual number of the Y-axis assigned
                to that mapping for XY Line plots. This option is not available
                for Polar Line plots.
            """
            return self._get_style(str, sv.NAME)

        @name.setter
        def name(self, name):
            self._set_style(str(name), sv.NAME)

        @property
        def show(self):
            """Display this linemap on the plot.

            :type: `bool`

            Example usage for turning on all linemaps::

                >>> for lmap in plot.linemaps():
                ...     lmap.show = True
            """
            return self.index in self.plot.active_linemap_indices

        @show.setter
        def show(self, show):
            assignment = AssignOp.PlusEquals if show else AssignOp.MinusEquals
            session.set_style({self.index}, sv.ACTIVELINEMAPS,
                              assignmodifier=assignment,
                              uniqueid=self.plot.frame.uid)

        @property
        def zone_index(self):
            """Zero-based index of the `Zone <data_access>` this :ref:`Linemap` will draw.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).zone_index = 2
            """
            return self._get_style(Index, sv.ASSIGN, sv.ZONE)

        @zone_index.setter
        def zone_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.ZONE)

        @property
        def zone(self):
            """`Zone <data_access>` this :ref:`Linemap` will draw.

            :type: `Zone <data_access>`

            Example usage::

                >>> plot.linemap(0).zone = dataset.zone('Zone 1')
            """
            return self.plot.frame.dataset.zone(self.zone_index)

        @zone.setter
        def zone(self, zone):
            self.zone_index = zone.index

        @property
        def show_in_legend(self):
            """Show this :ref:`Linemap` in the legend.

            :type: `LegendShow`

            Possible values:

            `LegendShow.Yes`
                The mapping appears in the legend even if the mapping is turned off
                (deactivated) or its entry in the table looks exactly like another
                mapping's entry.

            `LegendShow.No`
                The mapping never appears in the legend.

            `LegendShow.Auto` (default)
                The mapping appears in the legend only when the mapping is turned
                on. If two mappings would result in the same entry in the legend,
                only one entry is shown.
            """
            return self._get_style(LegendShow, sv.ASSIGN, sv.SHOWINLEGEND)

        @show_in_legend.setter
        def show_in_legend(self, value):
            self._set_style(LegendShow(value or 1), sv.ASSIGN, sv.SHOWINLEGEND)

        @property
        def sort_mode(self):
            """Mode controlling which `Variable` to use when sorting lines.

            :type: `LineMapSort`

            Possible values:  `LineMapSort.SpecificVar`,
            `LineMapSort.IndependentVar`, `LineMapSort.DependentVar` or
            `LineMapSort.None_`.

            Example usage::

                >>> from tecplot.constant import LineMapSort
                >>> plot.linemap(0).sort_mode = LineMapSort.DependentVar
            """
            return self._get_style(LineMapSort, sv.ASSIGN, sv.SORT)

        @sort_mode.setter
        def sort_mode(self, value):
            try:
                self._set_style(LineMapSort(value), sv.ASSIGN, sv.SORT)
            except TecplotSystemError:
                msg = dedent('''\
                    A variable must be set using sort_variable before the mode can
                    be set to SpecificVar''')
                raise TecplotLogicError(msg)

        @property
        def sort_variable(self):
            """Specific `Variable` used when listing lines.

            :type: `Variable`

            The ``sort_mode`` attribute must be set to `LineMapSort.SpecificVar`::

                >>> from tecplot.constant import LineMapSort
                >>> plot.linemap(0).sort_by = LineMapSort.SpecificVar
                >>> plot.linemap(0).sort_variable = dataset.variable('P')
            """
            idx = self.sort_variable_index
            return self.plot.frame.dataset.variable(idx)

        @sort_variable.setter
        def sort_variable(self, value):
            self.sort_variable_index = value.index

        @property
        def sort_variable_index(self):
            """Zero-based index of the specific `Variable` used for sorting.

            :type: `integer <int>`

            The ``sort_mode`` attribute must be set to `LineMapSort.SpecificVar`::

                >>> from tecplot.constant import LineMapSort
                >>> plot.linemap(0).sort_by = LineMapSort.SpecificVar
                >>> plot.linemap(0).sort_variable_index = 3
            """
            return self._get_style(Index, sv.ASSIGN, sv.SORTVAR)

        @sort_variable_index.setter
        def sort_variable_index(self, value):
            self._set_style(Index(value), sv.ASSIGN, sv.SORTVAR)

        @property
        def curve(self):
            """`LinemapCurve` style and fitting-method control for lines.

            :type: `LinemapCurve`
            """
            return LinemapCurve(self)

        @property
        def indices(self):
            """`LinemapIndices` object controlling which lines are shown.

            :type: `LinemapIndices`
            """
            return LinemapIndices(self)

        @property
        def line(self):
            """`LinemapLine` style for lines to be drawn.

            :type: `LinemapLine`
            """
            return LinemapLine(self)

        @property
        def symbols(self):
            """`LinemapSymbols` style for markers at points along the lines.

            :type: `LinemapSymbols`
            """
            return LinemapSymbols(self)

    class XYLinemap(Linemap):
        """Data mapping for 2D Cartesian line plots.

        Linemaps connect a specific `Zone <data_access>`/`Variable` combination to
        a line or set of lines, depending on the dimension of the data if ordered.
        Linemaps can share any of the axes available in the plot and orientation
        can be verical or horizontal by setting the independent variable with
        `XYLinemap.function_dependency`:

        .. code-block:: python
            :emphasize-lines: 13-16,17-23

            from os import path
            import tecplot as tp
            from tecplot.constant import PlotType, Color

            examples_dir = tp.session.tecplot_examples_directory()
            infile = path.join(examples_dir, 'XY', 'rainfall.plt')
            dataset = tp.data.load_tecplot(infile)

            frame = tp.active_frame()
            frame.plot_type = PlotType.XYLine
            plot = frame.plot()

            lmap = plot.linemap(0)
            lmap.line.line_thickness = 0.8
            lmap.line.color = Color.DeepRed
            lmap.y_axis.title.color = Color.DeepRed

            lmap = plot.linemap(1)
            lmap.show = True
            lmap.y_axis_index = 1
            lmap.line.line_thickness = 0.8
            lmap.line.color = Color.Blue
            lmap.y_axis.title.color = Color.Blue

            tp.export.save_png('linemap_xy.png', 600)

        ..  figure:: /_static/images/linemap_xy.png
            :width: 300px
            :figwidth: 300px
        """

        @property
        def x_axis_index(self):
            """Zero-based index of the x-axis used by this linemap.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).x_axis_index = 2
            """
            return self._get_style(Index, sv.ASSIGN, sv.XAXIS)

        @x_axis_index.setter
        def x_axis_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.XAXIS)

        @property
        def x_axis(self):
            """X-axis used by this linemap.

            :type: `LineAxis`

            Example usage::

                >>> plot.linemap(0).x_axis = plot.axes.x_axis(2)
            """
            return self.plot.axes.x_axis(self.x_axis_index)

        @x_axis.setter
        def x_axis(self, axis):
            self.x_axis_index = axis.index

        @property
        def y_axis_index(self):
            """Zero-based index of the y-axis used by this linemap.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).y_axis_index = 2
            """
            return self._get_style(Index, sv.ASSIGN, sv.YAXIS)

        @y_axis_index.setter
        def y_axis_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.YAXIS)

        @property
        def y_axis(self):
            """Y-axis used by this linemap.

            :type: `LineAxis`

            Example usage::

                >>> plot.linemap(0).x_axis = plot.axes.y_axis(2)
            """
            return self.plot.axes.y_axis(self.y_axis_index)

        @y_axis.setter
        def y_axis(self, axis):
            self.y_axis_index = axis.index

        @property
        def x_variable_index(self):
            """Zero-based index of the `Variable` used for x-positions.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).x_variable_index = 2
            """
            return self._get_style(Index, sv.ASSIGN, sv.XAXISVAR)

        @x_variable_index.setter
        def x_variable_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.XAXISVAR)

        @property
        def x_variable(self):
            """`Variable` used for x-positions of this linemap.

            :type: `Variable`

            Example usage::

                >>> plot.linemap(0).x_variable = dataset.variable('P')
            """
            return self.plot.frame.dataset.variable(self.x_variable_index)

        @x_variable.setter
        def x_variable(self, variable):
            self.x_variable_index = variable.index

        @property
        def y_variable_index(self):
            """Zero-based index of the `Variable` used for y-positions.

            :type: `integer <int>`

            Example usage::

                >>> plot.linemap(0).y_variable_index = 2
            """
            return self._get_style(Index, sv.ASSIGN, sv.YAXISVAR)

        @y_variable_index.setter
        def y_variable_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.YAXISVAR)

        @property
        def y_variable(self):
            """`Variable` used for y-positions of this linemap.

            :type: `Variable`

            Example usage::

                >>> plot.linemap(0).y_variable = dataset.variable('Q')
            """
            return self.plot.frame.dataset.variable(self.y_variable_index)

        @y_variable.setter
        def y_variable(self, variable):
            self.y_variable_index = variable.index

        @property
        def function_dependency(self):
            """The independent variable for function evalulation.

            :type: `FunctionDependency`

            Possible values: `XIndependent`, `YIndependent`.

            Example usage::

                >>> from tecplot.constant import FunctionDependency
                >>> lmap = plot.linemap(0)
                >>> lmap.function_dependency = FunctionDependency.YIndependent
            """
            return self._get_style(FunctionDependency, sv.ASSIGN,
                                   sv.FUNCTIONDEPENDENCY)

        @function_dependency.setter
        def function_dependency(self, value):
            self._set_style(FunctionDependency(value), sv.ASSIGN,
                            sv.FUNCTIONDEPENDENCY)

        @property
        def bars(self):
            """`LinemapBars` style for bar charts.

            :type: `LinemapBars`
            """
            return LinemapBars(self)

        @property
        def error_bars(self):
            """`LinemapErrorBars` style for error bars.

            :type: `LinemapErrorBars`
            """
            return LinemapErrorBars(self)

    class PolarLinemap(Linemap):

        @property
        def r_axis(self):
            """Radial axis used by this linemap.

            :type: `RadialLineAxis`
            """
            return self.plot.axes.r_axis

        @property
        def theta_axis(self):
            """Angular axis used by this linemap.

            :type: `PolarAngleLineAxis`
            """
            return self.plot.axes.theta_axis

        @property
        def r_variable_index(self):
            return self._get_style(Index, sv.ASSIGN, sv.YAXISVAR)

        @r_variable_index.setter
        def r_variable_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.YAXISVAR)

        @property
        def r_variable(self):
            return self.plot.frame.dataset.variable(self.r_variable_index)

        @r_variable.setter
        def r_variable(self, variable):
            self.r_variable_index = variable.index

        @property
        def theta_variable_index(self):
            return self._get_style(Index, sv.ASSIGN, sv.XAXISVAR)

        @theta_variable_index.setter
        def theta_variable_index(self, index):
            self._set_style(Index(index), sv.ASSIGN, sv.XAXISVAR)

        @property
        def theta_variable(self):
            return self.plot.frame.dataset.variable(self.theta_variable_index)

        @theta_variable.setter
        def theta_variable(self, variable):
            self.theta_variable_index = variable.index

        @property
        def function_dependency(self):
            """The independent variable for function evalulation.

            :type: `FunctionDependency`

            Possible values: `RIndependent <FunctionDependency>`, `ThetaIndependent
            <FunctionDependency>`.
            """
            return self._get_style(FunctionDependency, sv.ASSIGN,
                                   sv.FUNCTIONDEPENDENCY)

        @function_dependency.setter
        def function_dependency(self, value):
            self._set_style(FunctionDependency(value), sv.ASSIGN,
                            sv.FUNCTIONDEPENDENCY)

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