chapman.py 文件源码

def chapman(z, Nm, Hm, H_O, exp=NP.exp):
    """
    Return Chapman function electron density at height *z*, maximum
    electron density at the F-peak *Nm*, height at the maximum *Hm*,
    and the scale height of atomic oxygen *H_O*. The exponential
    function can be overridden with *exp*.
    """
    return Nm * exp((1 - ((z - Hm) / H_O) - exp(-(z - Hm) / H_O)) / 2)