Since you’ve tagged this question with sympy, I will give such an example. From the documentation: http://docs.sympy.org/latest/modules/plotting.html. from sympy import var, plot_implicit var(‘x y’) plot_implicit(x*y**3 – y*x**3)
Don’t laugh, but the easiest would be to use the rectangle function, indeed 😉 %// radius r = 2; %// center c = [3 3]; pos = [c-r 2*r 2*r]; rectangle(‘Position’,pos,’Curvature’,[1 1]) axis equal but set the curvature of the rectangle to 1! The position vector defines the rectangle, the first two values x and … Read more
Try mathjax http://www.mathjax.org/ . I personally find it very good.
By using masked arrays you can avoid plotting selected regions of a curve. To remove the singularity at x=2: import matplotlib.numerix.ma as M # for older versions, prior to .98 #import numpy.ma as M # for newer versions of matplotlib from pylab import * figure() xx = np.arange(-0.5,5.5,0.01) vals = 1/(xx-2) vals = M.array(vals) mvals … Read more
One way would be to use numexpr. It’s mostly a module for optimizing (and multithreading) numpy operations but it can also handle mathematical python expressions: >>> import numexpr >>> numexpr.evaluate(‘2 + 4.1 * 3′) array(14.299999999999999) You can call .item on the result to get a python-like type: >>> numexpr.evaluate(’17 / 3′).item() 5.666666666666667 It’s a 3rd … Read more
How about SymPy? Their solver looks like what you need. Have a look at their source code if you want to build the library yourself…
I don’t believe there’s very good support for this, but you could try something like import matplotlib.pyplot from numpy import arange from numpy import meshgrid delta = 0.025 xrange = arange(-5.0, 20.0, delta) yrange = arange(-5.0, 20.0, delta) X, Y = meshgrid(xrange,yrange) # F is one side of the equation, G is the other F … Read more
Python’s own internal compiler can parse this, if you use Python notation. If your change the notation slightly, you’ll be happier. import compiler eq= “sin(x)*x**2” ast= compiler.parse( eq ) You get an abstract syntax tree that you can work with.
The shunting yard algorithm is the right tool for this. Wikipedia is really confusing about this, but basically the algorithm works like this: Say, you want to evaluate 1 + 2 * 3 + 4. Intuitively, you “know” you have to do the 2 * 3 first, but how do you get this result? The … Read more