arsptp - (Rayleigh-)Pitot relations given p0/p or p02/p1

DOUBLE PRECISION FUNCTION AR15AB(G,P0,IS_SUB,IERR)
  DOUBLE PRECISION G, P0
  LOGICAL IS_SUB
  INTEGER IERR

Compute the Rayleigh-Pitot properties given a one of the pressure ratios $p0/p$ or $p02/p1$ .

Performance

Arguments

G - REAL: ENTRY: Specific heat constant $γ$ .
P0 - REAL: ENTRY: The pressure ratio $p0/p≥ 1$ or $p02/p1≥ ((1+ γ)/2)(γ/(γ-1))$ depending upon is_sub.
IS_SUB - BOOLEAN: ENTRY: Whether p0 refers to a Pitot pressure fraction (true) or to a Rayleigh-Pitot pressure fraction (false).
RESULT - ARRAY OF REAL: EXIT: Array with result properties as described in 13.
IERR - INTEGER: EXIT: (optional) Return status code.

Status codes

Return Values
The Mach number $M$ or NAN on error.