Metadata-Version: 2.1
Name: pybde
Version: 0.4
Summary: Boolean Delay Equation simulator
Home-page: https://github.com/EPCCed/pybde/wiki/pybde
Author: Ally Hume
Author-email: a.hume@epcc.ed.ac.uk
License: MIT
Description: ## Introduction
        
        Boolean Delay Equations (BDEs) can be used to model a variety of problems.  ```pybde``` allows
        to you write Boolean delay equations models in Python and simulate them.
        
        More detailed documentation can be found at: Documentation for pynmmso can be found at: https://github.com/EPCCed/pybde/wiki/pybde
        
        Code for the examples included here can be found at: https://github.com/EPCCed/pybde-examples
        
        ## Install pybde
        
        ```pybde``` requires Python 3.5 or above.  
        
        You can install `pybde` using `pip`:
        
        ```
        pip install pybde
        ```
        
        ## Writing and simulating a model
        
        The first model we will simulate has a single variable and a single delay.  The single equation 
        for the model is:
        
        x(t) = NOT x(t-Ï„)
        
        where x is the model variable, t is time, and Ï„ is the time delay.  In our example Ï„ = 1.
        
        To implement this model we must write a function that when given the state of the model's
        variables at each of the time delays returns the state of the model's variables at the current time.
        The argument to this function is a list of lists.  If the argument is called `z` then `z[i][j]` contains
        the state of the _j_ th variable at the _i_ th delay (note that indexing starts from 0).
        
        So in this case we can write our model in the following function:
        
        ```
        def my_model(z):
           return [ not z[0][0] ]
        ```
        
        To simulate this model we must provide:
        * the history of the state variables prior to the start of the simulation,
        * the time delays, and
        * the end time for the simulation.
        
        Our model has only one variable and we will specify its history from t=0 until t=1.  We 
        define this as a Boolean time series specifying:
        * a list of time points where the state changes, 
        * a corresponding list of the new variable state at each of these time points, and
        * the final time point for the time series.
        
        The code to do this is:
        
        ```
        history = BooleanTimeSeries([0], [True], 1)
        ```
        
        We only have a single delay parameter in this model and its value is 1 so the delay_parameters list is:
        ```
        delay_parameters = [ 1 ]
        ```
        
        Our simulation will run from the end of the defined history (t=1) and will end at time t=5:
        ```
        end_time = 5
        ```
        
        Note that the history must last at least a long as the maximum delay parameter.  In this case both are 1 seconds
        so this is valid.
        
        Putting this altogether gives:
        
        ```
        from pybde import BDESolver, BooleanTimeSeries
        
        
        def my_model(z):
            return [not z[0][0]]
        
        
        def main():
            history = BooleanTimeSeries([0], [True], 1)
            delay_parameters = [1]
            end_time = 5
        
            my_bde_solver = BDESolver(my_model, delay_parameters, [history])
            my_bde_solver.solve(end_time)
            my_bde_solver.show_result()
        
        
        if __name__ == "__main__":
            main()
        ```
        
        This will display the following plot showing the state of the variable
        over the duration of the simulation.
        
        ![One variable one delay output](https://github.com/EPCCed/pybde/wiki/images/v1.0/single_variable_output.png)
        
        ## Multiple variables and delays
        
        In this example our model will contain two variable and two delays.  The model
        equations are:
        
        x1(t) = x2(t-Ï„1)
        
        x2(t) = NOT x1(t-Ï„2)
        
        where x1 and x2 are the model variables, t is time, and Ï„1 and Ï„2 are the time delays.
        In this example example Ï„1 = 1 and Ï„2 = 0.5.
        
        We implement this model with the following function.  Note that the first index 
        specifies the delay and the second index specifies the variable.  Here we have
        explicitly named index variables so the code looks more like the equations
        expressed above.
        
        ```
        def my_two_variable_model(z):
            x1 = 0
            x2 = 1
            tau1 = 0
            tau2 = 1
            return [z[tau1][x2], not z[tau2][x1]]
        ```
        
        We wish to start the simulation at t=2 with input history until this point as shown below:
        
        ![Two variables, two delays history](https://github.com/EPCCed/pybde/wiki/images/v1.0/two_variables_history.png)
        
        So we specify the history of variables x1 and x2 as:
        
        ```
        x1_history = BooleanTimeSeries([0, 1.5], [True, False], 2)
        x2_history = BooleanTimeSeries([0, 1], [True, False], 2)
        ```
        
        To distinguish the variables when plotting results we can give them
        labels and matlplotlib plotting styles:
        
        ```
        x1_history.label = "x1"
        x1_history.style = "-r"
        x2_history.label = "x2"
        x2_history.style = "-b"
        ```
        
        So the full simulation is run with the following code:
        
        ```
        from pybde import BDESolver, BooleanTimeSeries
        
        
        def my_two_variable_model(z):
            x1 = 0
            x2 = 1
            tau1 = 0
            tau2 = 1
            return [z[tau1][x2], not z[tau2][x1]]
        
        
        def main():
            x1_history = BooleanTimeSeries([0, 1.5], [True, False], 2)
            x2_history = BooleanTimeSeries([0, 1], [True, False], 2)
        
            x1_history.label = "x1"
            x1_history.style = "-r"
            x2_history.label = "x2"
            x2_history.style = "-b"
        
            delay_parameters = [1, 0.5]
        
            end_time = 6
        
            my_bde_solver = BDESolver(my_two_variable_model, delay_parameters,[x1_history, x2_history])
            my_bde_solver.solve(end_time)
            my_bde_solver.show_result()
        
        
        if __name__ == "__main__":
            main()
        ```
        
        This will display the following plot showing the state of the variables
        over the duration of the simulation.
        
        ![Two variables, two delays output](https://github.com/EPCCed/pybde/wiki/images/v1.0/two_variables_output.png)
        
        
        ## Forcing inputs
        
        Forcing inputs are input variables that must be specified for the whole duration of
        the simulation.  These variables' state are not determined by model equations but
        can be used within model equations to determine the state of other variables.
        
        As an example of forced inputs consider the following model equations:
        
        x1(t) = 1 if t mod 1 >= 0.5, 0 otherwise   
        
        x2(t) = x1(t-Ï„)                        
        
        where x1 and x2 are model state variables, t is the time and Ï„ is the delay.
        In this case Ï„ is 0.3.
        
        Here we can model x1 as a forcing input as we can define the value of x1 for
        the whole duration of the simulation. To specify x1 we must define the
        starting state and switch points for the whole simulation.  
        
        For a three second simulation this can be defined as:
        
        ```
        x1_input = BooleanTimeSeries([0, 0.5, 1, 1.5, 2, 2.5, 3], [False], 3)
        ```
        
        Note that in the code above we only specify the initial Boolean state rather than
        all seven Boolean states.  If the length of the state list is smaller than the length
        of the timepoint list then the state list is simply extended with alternative True
        and False values.  The above code is identical to:
        
        ```
        x1_input = BooleanTimeSeries([0, 0.5, 1, 1.5, 2, 2.5, 3], [False, True, False, True, False, True, False], 3)
        ```
        
        
        Given that x1 is a forcing variable the only normal variable will be
        x2.  The following code initialises it to `True` for 0.5 time units:
        
        ```
        x2_history = BooleanTimeSeries([0], [True], 0.5)
        ```
        
        The inputs to the simulation are shown in the following plot:
        
        ![Forcing input before simulation](https://github.com/EPCCed/pybde/wiki/images/v1.0/forcing_input_before.png)
        
        When using forcing inputs the state of forcing inputs at the various
        time delays is passed to the model function as a second 
        argument.  The model function is therefore:
        
        ```
        def my_forced_input_model(z, forced_inputs):
            tau = 0
            x1 = 0
            return [ forced_inputs[tau][x1] ]
        ```
        
        To run the simulation is very similar to before except the forcing inputs
        must be passed when constructing the ```BDESolver``` object:
        
        ```
        my_bde_solver = BDESolver(my_forcing_input_model, 
                                  delay_parameters, 
                                  [x2_history], 
                                  [x1_input])
        ```
        
        The whole code is:
        
        ```
        from pybde import BDESolver, BooleanTimeSeries
        
        
        def my_forcing_input_model(z, forcing_inputs):
            tau = 0
            x1 = 0
            return [ forcing_inputs[tau][x1] ]
        
        
        def main():
            x2_history = BooleanTimeSeries([0], [True], 0.5)
            x2_history.label = 'x2'
            x2_history.style = '-r'
        
            x1_input = BooleanTimeSeries([0, 0.5, 1, 1.5, 2, 2.5, 3], [False], 3)
            x1_input.label = 'x1'
            x1_input.style = '-b'
        
            delay_parameters = [0.3]
            end_time = 3
        
            my_bde_solver = BDESolver(my_forcing_input_model, 
                                      delay_parameters, 
                                      [x2_history], 
                                      [x1_input])
            my_bde_solver.solve(end_time)
        
            my_bde_solver.show_result()
        
        
        if __name__ == "__main__":
            main()
        ```
        
        
        Running this simulation produces the following plot:
        
        ![Forcing input after simulation](https://github.com/EPCCed/pybde/wiki/images/v1.0/forcing_input_after.png)
        
        ## Plotting and printing result data
        
        The `BDESolver` class provides basic methods to plot or print results. These
        can be useful to quickly see the result of a simulation. For more detailed
        analysis of the results see the `BooleanTimeSeries` convenience functions
        below.
        
        ### `plot_result()`
        
        `plot_result` plots the variable state and any forcing inputs to a single
        plot. Line styles and labels are taken from the `BooleanTimeSeries` objects 
        passed to the solver. The plot will not be displayed.  Use `matplotlib` functions
        to display or save the plot.  For example:
        
        ```
        import matplotlib.pyplot as plt
        
        ...
        
        plt.figure(figsize=(5, 2))
        my_bde_solver.plot_result()
        plt.savefig("result_plot.png")
        ```
        
        ### `show_result()`
        
        `show_result` is similar to `plot_result` except the `show()` function is called
        to display the plot.
        
        ### `print_result(file=sys.stdout)`
        
        `print_result` prints the state of the variables at each switch point producing
        output such as:
        
        ```
            0.00 ->     1.00 : T T 
            1.00 ->     1.50 : T F 
            1.50 ->     2.00 : F F 
            2.00 ->     3.00 : F T 
            3.00 ->     3.50 : T T 
            3.50 ->     4.50 : T F 
            4.50 ->     5.00 : F F 
            5.00 ->     6.00 : F T 
            6.00 ->     6.00 : T T 
        ```
        
        By default the method prints to standard output but alternative outputs can be
        specified using the `file` argument.
        
        
        ## Obtaining the result data
        
        The `solve` method of `BDESolver` returns a list containing a `BooleanTimeSeries`
        object for each of the variables.
        
        You can obtain and process the results with code such as:
        
        ```
        result = my_bde_solver.solve(end_time)
        for bts in result:
            print(bts)
        ```
        
        Or you can explicitly obtain the time series for each variable using code such as:
        
        ```
        [x1_result, x2_result] = my_bde_solver.solve(end_time)
        ```
        
        
        
        ## `BooleanTimeSeries` convenience functions
        
        The `BooleanTimeSeries` class includes various convenience functions that help
        processing and manipulating Boolean time series data.  These are documented
        here.
        
        ### BooleanTimeSeries(list_of_switch_point_times, list_of_variable_state, end_time, label=None, style=None)
        
        The `BooleanTimeSeries` constructor takes a list of switch point times,
        a list of the new variable state at each of these times and the end_time of the
        time series. These values are represent the state of the Boolean time series.
        
        The `list_of_switch_point_times` parameter may be a list of numeric values or
        a numpy array of numeric values.
        
        The `list_of_variable_state` may be a list of `bool` values or a numpy array
        of `bool` values. To save specifying a list of alternating `True` and `False`
        values it is possible to specify a list with just the first state value and
        this will automatically be padded out with alternating Boolean values for
        each specified switch point.
        
        The optional `label` parameter specifies a label to use when plotting the data.
        The value also be accessed and set using the class's `label` attribute.
        
        The optional `style` parameter specifies a style to use when plotting the data.
        The value also be accessed and set using the class's `style` attribute.
        
        
        ### plot(offset=0, scale=1)
        
        Plots the Boolean time series to a `matplotlib` plot. If present the plot
        label and line style are taken from the `label` and `style` attributes of this
        `BooleanTimeSeries` instance.
        
        The plot will not be displayed. To show or save the plot use the appropriate
        `matplotlib` functionality.
        
        The `offset` parameter can be used to specify an offset from 0 and 1 at which
        to plot the line.  This can be very useful if plotting multiple Boolean time
        series on the same plot.
        
        The `scale` parameter can be used to specify that the value to plot for `True`
        is a value other than 1.  This can be useful when plotting Boolean time series
        alongside experimental data.
        
        ### show(offset=0, scale=1)
        
        `show` is similar to `plot` expect the matplotlib `show` method will be called
        to display the plot.
        
        ### plot_many(list_of_time_series, offset=0.05)
        
        Static method that plots multiple Boolean time series in a single plot. The offset
        parameter is used to specify the offset between plots in the y axis.
        
        Example of usage:
        
        ```
        import matplotlib.pyplot as plt
        
        ...
        
        plt.figure(figsize=(5, 2))
        list_of_boolean_time_series = my_bde_solver.solve(end_time)
        BooleanTimeSeries.plot_many(list_of_boolean_time_series, offset=0.1)
        plt.savefig("result_plot.png")
        ```
        
        
        ### show_many(list_of_time_series, offset=0.05)
        
        Static method that is similar to `plot_many` but calls the `matplotlib` `show`
        function to display the plot.
        
        ### to_plot_data(offset=0, scale=1)
        
        The `to_plot_data` method can use used to obtain the Boolean time series in a format suitable
        for plotting as using various plotting libraries.  The method returns two
        lists: one for x (time) values and the other of y values.
        
        This method is useful if you wish to take full control over how the results
        are plotted. 
        
        The `offset` parameter can be used to specify an offset from 0 and 1 at which
        to plot the line.  This can be very useful if plotting multiple Boolean time
        series on the same plot.
        
        The `scale` parameter can be used to specify that the value to plot for `True`
        is a value other than 1.  This can be useful when plotting Boolean time series
        alongside experimental data.
        
        Example of usage:
        
        ```
        from pybde import BooleanTimeSeries
        
        bts = BooleanTimeSeries([0, 2, 6, 10], [True], 12)
        
        x, y = bts.to_plot_data()
        
        print('x = {}'.format(x))
        print('y = {}'.format(y))
        ```
        
        Outputs:
        
        ```
        x = [0, 2, 2, 6, 6, 10, 10, 12]
        y = [1, 1, 0, 0, 1, 1, 0, 0]
        ```
        
        
        ### absolute_threshold(t, y, threshold) 
        
        The static `absolute_threshold` method produces Boolean time series data from
        numerical time series data. An absolute threshold value is specified above
        which the Boolean time series will be `True` and below which the Boolean time
        series will be `False`.
        
        Input parameter `t` must be either a list of numeric values or a numpy array of
        numeric values. Input parameter `y` must be either a list of `bool` values
        or a numpy array of `bool` values.
        
        Linear interpolation is used to determine the time at which the state
        changes.
        
        For example:
        
        ```
        from pybde import BooleanTimeSeries
        
        t = [0,  1, 2, 3,  4]
        y = [0, 10, 8, 3, 12]
        
        bts = BooleanTimeSeries.absolute_threshold(t, y, 5)
        
        print(bts)
        ```
        
        produces:
        
        ```
        t=[0, 0.5, 2.6, 3.2222222222222223], y=[False, True, False, True], end=4
        ```
        
        ### relative_threshold(t, y, threshold)
        
        The static `relative_threshold` method produces Boolean time series data from
        numerical time series data. An threshold value is calculated specified above
        which the Boolean time series will be `True` and below which the Boolean time
        series will be `False`.  The absolute threshold value used is calculated
        as `(max(y)-min(y))*threshold + min(y)`.  The specified threshold parameter
        should be a number between 0 and 1.
        
        Input parameter `t` must be either a list of numeric values or a numpy array of
        numeric values. Input parameter `y` must be either a list of `bool` values
        or a numpy array of `bool` values.
        
        Linear interpolation is used to determine the time at which the state
        changes.
        
        For example:
        
        ```
        from pybde import BooleanTimeSeries
        
        t = [0,  1, 2, 3,  4]
        y = [4, 10, 8, 2, 12]
        
        bts = BooleanTimeSeries.relative_threshold(t, y, 0.5)
        
        print(bts)
        ```
        
        produces:
        
        ```
        t=[0, 0.5, 2.1666666666666665, 3.5], y=[False, True, False, True], end=4
        ```
        
        ### cut(new_start, new_end, keep_switch_on_end=False)
        
        The `cut` method return a new `BooleanTimeSeries` which is a sub-series of the original
        series. The returned series will run from the specified new start time to the specified
        new end time. By default a state switch that occurs on the new end time will be omitted,
        the `keep_switch_on_end` flag can be set to `True` to keep such state switches.
        
        For example:
        
        ```
        > from pybde import BooleanTimeSeries
        > bts = BooleanTimeSeries([0,1,2,3,4,5,6], [True], 7)
        > print(bts)
        t=[0, 1, 2, 3, 4, 5, 6], y=[True, False, True, False, True, False, True], end=7
        
        > print( bts.cut(0,6) )
        t=[0, 1, 2, 3, 4, 5], y=[True, False, True, False, True, False], end=6
        
        > print( bts.cut(0, 6, keep_switch_on_end=True) )
        t=[0, 1, 2, 3, 4, 5, 6], y=[True, False, True, False, True, False, True], end=6
        
        > print( bts.cut(1.5, 4.5) )
        t=[1.5, 2, 3, 4], y=[False, True, False, True], end=4.5
        ```
        
        ### hamming_distance(boolean_time_series)
        
        The `hamming_distance` method compares the Boolean Time Series with another 
        Boolean time series and returns the total duration for which they differ.
        Two time series that are identical will have a Hamming distance of zero.
        
        For example:
        
        ```
        > from pybde import BooleanTimeSeries
        > bts = BooleanTimeSeries([0,1,2,3,4,5,6], [True], 7)
        > print(bts.hamming_distance(bts))
        0.0
        
        > bts2 = BooleanTimeSeries([0,1.5,2,3,4.3,5,6], [True], 7)
        print(bts.hamming_distance(bts2))
        0.8
        ```
        
        ### merge(list_of_time_series)
        
        The static `merge` method takes a list of BooleanTimeSeries objects and outputs
        two lists.  The first list is the switch point times and the second list is
        a list of lists of the state variables at these time points.
        
        For example:
        
        ```
        from pybde import BooleanTimeSeries
        
        bts1 = BooleanTimeSeries([0, 1.0, 2.0], [True], 3)
        bts2 = BooleanTimeSeries([0, 1.5, 2.5], [True], 3)
        
        t, y = BooleanTimeSeries.merge([bts1, bts2])
        
        print('t = {}'.format(t))
        print('y = {}'.format(y))
        ```
        
        outputs:
        
        ```
        t = [0, 1.0, 1.5, 2.0, 2.5]
        y = [[True, True], [False, True], [False, False], [True, False], [True, True]]
        ```
        
        ### unmerge(list_of_switch_timepoints, list_of_lists_of_variable_states, end)
        
        The static function `unmerge` is the opposite of `merge`. `unmerge` takes as input 
        a list a switch point times, a list of list of variable states at these
        time points and the time series end time and returns a list of BooleanTimeSeries objects.
        
        For example:
        
        ```
        from pybde import BooleanTimeSeries
        
        t = [0, 1.0, 1.5, 2.0, 2.5]
        y = [[True, True], [False, True], [False, False], [True, False], [True, True]]
        
        for bts in BooleanTimeSeries.unmerge(t, y, 3):
            print(bts)
        ```
        
        outputs
        
        ```
        t=[0, 1.0, 2.0], y=[True, False, True], end=3
        t=[0, 1.5, 2.5], y=[True, False, True], end=3
        ```
        
        ## Do not include switch points at the end of variable's history
        
        When running a simulation the input history time series must not end on a switch point.
        This is because when the simulation starts from the time point the model equations may
        contradict the history state at this point. To avoid this simply remove the final switch
        point from the history.  This can be easily achieved using the `cut` function which
        by default removes any switch point at the end of the time series duration.  For example:
        
        ```
        > hist = BooleanTimeSeries([0,1,2], [True], 2)
        > print(hist)
        t=[0, 1, 2], y=[True, False, True], end=2
        > hist = hist.cut(0,hist.end)
        > print(hist)
        t=[0, 1], y=[True, False], end=2
        ```
        
        ## Logging
        
        `pybde` using Python's [logging library](https://docs.python.org/3/library/logging.html) to provide
        some debug logging. For example, the following line can be used to turn own debug logging:
        
        ```
        import logging
        
        logging.basicConfig(level=logging.DEBUG)
        ```
        
        ## Numerical accuracy
        
        The implementation of `pydbe` has to compare possible switch times generated in 
        different ways to see if they are the same time.  For example, is t1+Ï„2 the timepoint
        as t2+Ï„1. To perform comparisons of floating point numbers `pydbe` uses [`math.isclose`](https://docs.python.org/3.5/library/math.html#math.isclose) function.  This function
        defines the acceptable accuracy using the `rel_tol` and `abs_tol` arguments. To specify
        non-default values for these arguments you can specify `rel_tol` and `abs_tol` arguments
        when constructing the `BDESolver` object.
        
        The `BooleanTimeSeries` class also performs some floating point comparisons and adopts
        the same approach a `BSESolver`.  To alter the default relative and absolute tolerances
        for the `BooleanTimeSeries` class set the `rel_tol` and `abs_tol` static attributes of
        the class.
        
        ## Acknowledgements
        
        This work was supported by the Engineering and Physical Sciences Research Council (grant number [EP/N018125/1](https://gow.epsrc.ukri.org/NGBOViewGrant.aspx?GrantRef=EP/N018125/1))
        
        
        
        
        
        
        
        
Keywords: BDE,boolean,delay,equations,solver,simulator
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Topic :: Scientific/Engineering
Classifier: Operating System :: OS Independent
Requires-Python: >=3.5
Description-Content-Type: text/markdown
