1 DOUBLE PRECISION FUNCTION MZABS(ZR, ZI) 2C***BEGIN PROLOGUE ZABS 3C***REFER TO ZBESH,ZBESI,ZBESJ,ZBESK,ZBESY,ZAIRY,ZBIRY 4C 5C ZABS COMPUTES THE ABSOLUTE VALUE OR MAGNITUDE OF A DOUBLE 6C PRECISION COMPLEX VARIABLE CMPLX(ZR,ZI) 7C 8C***ROUTINES CALLED (NONE) 9C***END PROLOGUE ZABS 10 DOUBLE PRECISION ZR, ZI, U, V, Q, S 11 12 MZABS = ZABS(CMPLX(ZR,ZI,kind=KIND(1.0D0))) 13 RETURN 14 END 15 16c U = DABS(ZR) 17c V = DABS(ZI) 18c S = U + V 19C----------------------------------------------------------------------- 20C S*1.0D0 MAKES AN UNNORMALIZED UNDERFLOW ON CDC MACHINES INTO A 21C TRUE FLOATING ZERO 22C----------------------------------------------------------------------- 23c S = S*1.0D+0 24c IF (S.EQ.0.0D+0) GO TO 20 25c IF (U.GT.V) GO TO 10 26c Q = U/V 27c ZABS = V*DSQRT(1.D+0+Q*Q) 28c RETURN 29c 10 Q = V/U 30c ZABS = U*DSQRT(1.D+0+Q*Q) 31c RETURN 32c 20 ZABS = 0.0D+0 33c RETURN 34c END 35