var/da/da_biascorr_airmass/pythag.f90

   1 FUNCTION pythag(a,b)
   2 IMPLICIT NONE
   3 INTEGER, PARAMETER :: sp = 8
   4 REAL(sp), INTENT(IN) :: a,b
   5 REAL(sp) :: pythag
   6 !Computes (a2 + b2)1/2 without destructive under.ow or over.ow.
   7 REAL(sp) :: absa,absb
   8 absa=abs(a)
   9 absb=abs(b)
  10 if (absa > absb) then
  11 pythag=absa*sqrt(1.0+(absb/absa)**2)
  12 else
  13 if (absb == 0.0) then
  14 pythag=0.0
  15 else
  16 pythag=absb*sqrt(1.0+(absa/absb)**2)
  17 end if
  18 end if
  19 END FUNCTION pythag