appl121105_iotorus.f2j

Convert f value to j value

''' Convert f value to j value
'''
import numpy as np

def f2j(f, ene, mass):
    ''' Convert distribution function to differential flux.

    :param f: Distribution function in the unit of s^3 / m^6.
    :param ene: Energy in eV.
    :param mass: Mass in AMU.
    :returns: Differential flux in /cm2 sr eV s.

    >>> print('%.2e' % f2j(2.04751735385e-07, 800., 16.))
    1.17e+06
    '''
    m = mass * 1.67e-27
    j = 2 * ene * f / (m ** 2) * 1e-4 * (1.60e-19)**2
    return j


def ene(vel, mass):
    ''' Energy in eV

    :param vel: Velocity in km/s
    :param mass: Mass in AMU
    :returns: Energy in eV.

    >>> print('%.2f' % ene(13.8, 1))
    0.99
    '''
    m = mass * 1.67e-27  # kg
    v = vel * 1e3  # m/s

    e = v * v * m / 2. / 1.60e-19
    return e

def vel(ene, mass):
    ''' Return velocity in km/s

    :param ene: Energy in eV.
    :param mass: Mass in AMU
    :returns: Velocity in km/s.

    >>> print('%.1f' % vel(1000, 1))
    437.7

    >>> print('%.1f' % vel(1000, 16))
    109.4
    '''
    m = mass * 1.67e-27
    v = np.sqrt(np.array(ene) * 1.60e-19 * 2 / m)
    return v / 1e3

    
import unittest
import doctest


def doctests():
    return unittest.TestSuite((
        doctest.DocTestSuite(),
        ))
if __name__ == '__main__':
    unittest.main(defaultTest='doctests')