meijerint.py 文件源码

def _guess_expansion(f, x):
    """ Try to guess sensible rewritings for integrand f(x). """
    from sympy import expand_trig
    from sympy.functions.elementary.trigonometric import TrigonometricFunction
    from sympy.functions.elementary.hyperbolic import HyperbolicFunction
    res = [(f, 'originial integrand')]

    expanded = expand_mul(res[-1][0])
    if expanded != res[-1][0]:
        res += [(expanded, 'expand_mul')]

    expanded = expand(res[-1][0])
    if expanded != res[-1][0]:
        res += [(expanded, 'expand')]

    if res[-1][0].has(TrigonometricFunction, HyperbolicFunction):
        expanded = expand_mul(expand_trig(res[-1][0]))
        if expanded != res[-1][0]:
            res += [(expanded, 'expand_trig, expand_mul')]

    return res