Compiler Library/XL Reference Manual (32650-90029)

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is a real identifier of the matrix for D, an

integer identifier.

Result: CINVERT replaces the original matrix, and D

equals 1 if the matrix is non-singular or 0 if

the matrix is singular and no inverse exists.

HP FORTRAN 77/XL: Callable as a system intrinsic:

CALL CINVERT(N, A, D)

or as a system intrinsic statement.

Error: None.

CLOG (or CLOG')

CLOG calculates the natural logarithm of a complex number.

Declaration

Complex numbers in HP FORTRAN 77/XL programs are represented as an

ordered pair of real numbers: one for the real part

and one for the

imaginary part

. Thus, complex numbers occupy eight bytes.

TYPE complex=RECORD

realpart:REAL;

imagpart:REAL;

END;

FUNCTION CLOG(VAR x:complex):complex; EXTERNAL;

Accuracy

Depends on the accuracy of ALOG, SQRT, and ATAN2.

Attributes

Parameter: Any nonzero complex number representable in two

real numbers; both parts must not be zero.

Result: A complex number.

HP FORTRAN 77/XL: Intrinsic function: Y=CLOG(X).

Error: See the ALOG, SQRT, and ATAN2 error

descriptions.

COS (or COS')

COS calculates the cosine of a real number in radians.

Declaration

FUNCTION COS(VAR x:REAL):REAL; EXTERNAL;

Accuracy

When x-y ~ ∈ , maximum f-g ~ ∈ sin x