Function luminosityDistance( z, H0, omegaM, omegaLambda )

Description:
Luminosity distance.
Parameters:
z (floating point)
redshift
H0 (floating point)
Hubble constant in km/sec/Mpc
omegaM (floating point)
density ratio of the universe
omegaLambda (floating point)
normalised cosmological constant
Return Value (floating point):
luminosity distance in Mpc
Signature:
double luminosityDistance(double, double, double, double)