Two-line function to make expressions callable.

[Andre Bolle]

A function a fund quite useful, so I thought I'd pass it on.

def mkfun(expr):

    """ Creates a lambda with arguments which are the alphabetically ordered free symbols.
    E.g.
    f1 = mkfun(x**2)
    print(f1(3))
    f2 = mkfun(x**2 + y**2)
    print(f2(3,4))
    f3 = mkfun(x**2 + y**2 + z**2)
    print(f3(3,4,5))
    """
    free = list(ordered(expr.free_symbols))
    return lambda *x: expr.subs(zip(free,x))

[Andre Bolle]

Sorry about the spelling. I meant to write "A function which I find quite useful."

def mkfun(expr):

    free = list(ordered(expr.free_symbols))

    return lambda *x: expr.subs(zip(free,x))

:o)

[emanuel.c...@gmail.com]

Try :

In [1]: from sympy import Lambda

In [2]: help(Lambda)

HTH,

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