Sympy Plot Backends v3.1.0

What's Changed

• User can now specify an existing figure over which symbolic expressions will be plotted. Just use the ax= or fig= keyword argument.

• Added arrow_3d to spb.graphics.vectors in order to plot a single arrow in a three-dimensional space.

• Enhanced capabilities of line plots with the steps keyword argument. Possible values are "pre", "post", "mid", mimicking Matplotlib's step function.

• New features on the spb.graphics.control sub-module:

  • It now depends on the python-control module. This dependency allows the implementation of new plotting functions and to seamlessly deal with transfer functions from sympy, control and
    scipy.signal, supporting both continous-time and discrete-time systems.

  • Added support for MIMO systems.

  • Created sgrid, zgrid, ngrid, mcircles functions to easily create grids for control system plots. Appropriate keyword arguments have been created on all major plot functions in order to activate these grids.

  • Added plot_root_locus to the control submodule.

  • plot_bode now auto-computes an appropriate frequency range.

  • Removed the transfer function's Latex representation from the title of plots related to control systems. This decision is motivated from practical experience, where most of the transfer functions have floating point coefficients, which makes their Latex representation too big to fit into the small width of a plot.

• Refactoring of the series.py sub-module:

  • code has been re-organized to make extensibility easier and slightly improve performance. In particular, the mixin class CommonUniformEvaluation has been introduced, which handles all the machinery necessary to evaluate symbolic expressions. Series classes may or may not inherit from it. CommonUniformEvaluation allows for a better separation of scopes: data series that don't need that code are faster to instantiate.

  • Breaking: refactoring of NyquistLineSeries in order to use the control module. In particular, the get_data method now returns many more arrays.

  • Breaking: removed attribute use_quiver_solid_color from Vector2DSeries.

• Fixed bug with labels of 2D vector fields.