control.phaseplot.separatrices
- control.phaseplot.separatrices(sys, pointdata, timedata=None, gridspec=None, ax=None, _check_kwargs=True, suppress_warnings=False, **kwargs)[source]
Plot separatrices in the phase plane.
This function plots separatrices for a two-dimensional state space system.
- Parameters
- sys
NonlinearIOSystem
or callable(t, x, …) I/O system or function used to generate phase plane data. If a function is given, the remaining arguments are drawn from the
params
keyword.- pointdatalist or 2D array
List of the form [xmin, xmax, ymin, ymax] describing the boundaries of the phase plot or an array of shape (N, 2) giving points of at which to plot the vector field.
- timedataint or list of int
Time to simulate each streamline. If a list is given, a different time can be used for each initial condition in
pointdata
.- gridtypestr, optional
The type of grid to use for generating initial conditions: ‘meshgrid’ (default) generates a mesh of initial conditions within the specified boundaries, ‘boxgrid’ generates initial conditions along the edges of the boundary, ‘circlegrid’ generates a circle of initial conditions around each point in point data.
- gridspeclist, optional
If the gridtype is ‘meshgrid’ and ‘boxgrid’,
gridspec
gives the size of the grid in the x and y axes on which to generate points. If gridtype is ‘circlegrid’, thengridspec
is a 2-tuple specifying the radius and number of points around each point in thepointdata
array.- paramsdict or list, optional
Parameters to pass to system. For an I/O system,
params
should be a dict of parameters and values. For a callable,params
should be dict with key ‘args’ and value given by a tuple (passed to callable).- colormatplotlib color spec, optional
Plot the separatrices in the given color. If a single color specification is given, this is used for both stable and unstable separatrices. If a tuple is given, the first element is used as the color specification for stable separatrices and the second element for unstable separatrices.
- ax
matplotlib.axes.Axes
, optional Use the given axes for the plot, otherwise use the current axes.
- sys
- Returns
- outlist of Line2D objects
- Other Parameters
- rcParamsdict
Override the default parameters used for generating plots. Default is set by
config.defaults['ctrlplot.rcParams']
.- suppress_warningsbool, optional
If set to True, suppress warning messages in generating trajectories.
Notes
The value of
config.defaults['separatrices_radius']
is used to set the offset from the equilibrium point to the starting point of the separatix traces, in the direction of the eigenvectors evaluated at that equilibrium point.