Python-plotdf用以绘制2D微分方程相图的Python模块

Plot phase portraits of 2D differential equations using Python's `matplotlib` and `scipy` libraries. Inspired by Maxima's `plotdf` function. ## Usage To plot `dx/dt = y`, `dy/dt = -g sin(x) / l - b y/ (m l)`: ```` from math import sin from plotdf import plotdf def f(x,g=1,l=1,m=1,b=1): return np.array([x[1],-g*sin(x[0])/l-b*x[1]/m/l]) plotdf(f, # Function giving the rhs of the diff. eq. system np.array([-10,2]), # [xmin,xmax] np.array([-14,14]),# [ymin,ymax] [(1.05,-9),(0,5)], # list of initial values for trajectories (optional) # Additional parameters for `f` (optional) parameters={"g":9.8,"l":0.5,"m":0.3,"b":0.05}) ```` For the full list of parameters to `plotdf`, see `help(plotdf.plotdf)`. ## Dependencies Both Python 2 and 3 are supported. You need `matplotlib`, `numpy` and `scipy` installed. ## Installation The package is on PyPI so you can install it with $ pip install plotdf