This function evaluates the cosine for the argument in degrees.

Function Return Value

COSDG — Function value.   (Output)

Required Arguments

X — Argument in degrees for which the cosine is desired.   (Input)

FORTRAN 90 Interface

Generic:                              COSDG (X)

Specific:                             The specific interface names are S_COSDG and D_COSDG.

FORTRAN 77 Interface

Single:                                COSDG (X)

Double:                              The double precision function name is DCOSDG.

Description

To avoid unduly inaccurate results, the magnitude of x must not be so large that the integer part fills more than the computer word. Under no circumstances is the magnitude of x allowed to be larger than the largest representable integer because complete loss of accuracy occurs in this case.

Example

In this example, cos 100° computed and printed.

 

      USE COSDG_INT

      USE UMACH_INT

 

      IMPLICIT   NONE

!                                 Declare variables

      INTEGER    NOUT

      REAL       VALUE, X

!                                 Compute

      X     = 100.0

      VALUE = COSDG(X)

!                                 Print the results

      CALL UMACH (2, NOUT)

      WRITE (NOUT,99999) X, VALUE

99999 FORMAT (' COS(', F6.2, ' deg) = ', F6.3)

      END

Output

 

COS(100.00 deg) = -0.174

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