*DECK CARG FUNCTION CARG (Z) C***BEGIN PROLOGUE CARG C***PURPOSE Compute the argument of a complex number. C***LIBRARY SLATEC (FNLIB) C***CATEGORY A4A C***TYPE COMPLEX (CARG-C) C***KEYWORDS ARGUMENT OF A COMPLEX NUMBER, ELEMENTARY FUNCTIONS, FNLIB C***AUTHOR Fullerton, W., (LANL) C***DESCRIPTION C C CARG(Z) calculates the argument of the complex number Z. Note C that CARG returns a real result. If Z = X+iY, then CARG is ATAN(Y/X), C except when both X and Y are zero, in which case the result C will be zero. C C***REFERENCES (NONE) C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 770401 DATE WRITTEN C 861211 REVISION DATE from Version 3.2 C 891214 Prologue converted to Version 4.0 format. (BAB) C***END PROLOGUE CARG COMPLEX Z C***FIRST EXECUTABLE STATEMENT CARG CARG = 0.0 IF (REAL(Z).NE.0. .OR. AIMAG(Z).NE.0.) CARG = 1 ATAN2 (AIMAG(Z), REAL(Z)) C RETURN END