What software can be used to draw phase planes easily?
I want to input some $\begin{pmatrix}x_1 \\ x_2\end{pmatrix}=$blahblah, and have it plotted with or without initial conditions. Is there any software that can do this, or will I always need to do a great number of things, e.g. in Matlab you have to script together the functions and then the meshgrid and then the vectorplot etc.
Note: User Amzoti linked this beautiful tool: http://onlinesciencetools.com/tools/phaseportrait?dx=3*x%20%2B%20y&dy=4*x%2B3*y%2B1&domx_a=-5&domx_b=5&domy_a=-5&domy_b=5&domt_a=-5&domt_b=5&conc=10