Introduction - If you have any usage issues, please Google them yourself
H = DENSITYALT(rho) returns altitude, H, in the standard atmosphere that corresponds to the provided array of air densities, rho.
DENSITYALT is valid for the entire standard atmosphere up through the mesopause (86 km height). It assumes that all that is known is air density. If other combinations of pressure, temperature, and/or density are known, there exist more straightforward methods for calculating density altitude, e.g. in the troposphere DA = (288.15-T)/0.0065.