Compiler Library/XL Reference Manual (32650-90029)

2- 4

Attributes

Parameters: Real numbers; both must not be zero.

Result: A representable real number in one of the

following ranges:

See Chapter 1 for details on the internal

representation of real numbers.

HP FORTRAN 77/XL: Intrinsic function: Z=ATAN2(X,Y)

Error: If either of the arguments is a NaN or if both

arguments are zero (or Infinity), there are two

possible actions. If the INVALID trap is

enabled, the message "ATAN2(X,Y): X=Y=0.0 OR

X=Y=INFINITY OR ANY OF X AND Y=NaN" occurs.

Otherwise, the INVALID flag is set. In either

case, a quiet NaN is returned.

See Appendix A for more details.

CABS (or CABS')

CABS calculates the absolute value of a complex number.

Declaration

TYPE complex=RECORD

realpart:REAL;

imagpart:REAL;

END;

FUNCTION CABS(VAR x:complex):REAL; EXTERNAL;

Accuracy

Depends on the accuracy of SQRT.

Attributes

Parameter: Any complex number representable in two real

numbers: one for

and one for