using Prandtl-Glauert pressure approximation using Prandtl-Glauert pressure approximationdouble armcrpg(double g, double cp0, int *ierr);
Compute critical mach number given 
Prandtl-Glauert pressure approximation.
| Argument | Intent | Description |
| g | in | Specific heat constant |
| cp0 | in | Critical pressure coefficent |
| ierr | out | (optional) Return status code |
Specific heat ratio 
.
Iterative solver failed.
Return Value
Critical mach number 
or NAN on error.
. 
.