This documentation provides information for the usage of the IDL functions calc_dm.pro, calc_vol.pro, calc_t.pro and calc_scale.pro. These functions may be used within IDL to calculate the distance modulus, comoving volume element, lookback time and scale factor (respectively) from a given redshift z and a set of parameters

,

,
H0 and w.
It also provides information about the example files distplots.pro, volplots.pro, timeplots.pro, scaleplots.pro and scaleplot_z.pro.
The functions serve as interface to library routines written in C which perform the actual numerical calculations.