sympy/sympy — pull request #1193 by tesserahub (2012-04-02 02:56:27+00:00)
Title: Issue 3129: stats symbols

Moved `symbol` argument to the first argument and made it mandatory (removing the need for auto-variable generation). Allowed strings to be used as the symbol input (as they will be sympified) for continuous random variables.

todo/issues:
* Error about code-wrapping; not sure how to fix
* Doctests and tests have some extraneous symbol creation, making `x = Symbol('x')` and then passing it to `Binomial(x, n, p)` or whatever, when we could just do `Binomial('x', n, p)`
* Sympifying is imperfect: it doesn't let you use some strings as symbols: `E` returns Euler's constant, `N` returns the approximation function and so on. Instead, we should detect if the variable is already a symbol, and explicitly use `Symbol` if it is a string.