OpenLibm/slatec/dsindg.f
Viral B. Shah c977aa998f Add Makefile.extras to build libopenlibm-extras.
Replace amos with slatec
2012-12-31 16:37:05 -05:00

36 lines
1.1 KiB
Fortran

*DECK DSINDG
DOUBLE PRECISION FUNCTION DSINDG (X)
C***BEGIN PROLOGUE DSINDG
C***PURPOSE Compute the sine of an argument in degrees.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C4A
C***TYPE DOUBLE PRECISION (SINDG-S, DSINDG-D)
C***KEYWORDS DEGREES, ELEMENTARY FUNCTIONS, FNLIB, SINE, TRIGONOMETRIC
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C DSINDG(X) calculates the double precision sine for double
C precision argument X where X is in degrees.
C
C***REFERENCES (NONE)
C***ROUTINES CALLED (NONE)
C***REVISION HISTORY (YYMMDD)
C 770601 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890531 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C***END PROLOGUE DSINDG
DOUBLE PRECISION X, RADDEG
SAVE RADDEG
DATA RADDEG / 0.0174532925 1994329576 9236907684 886 D0 /
C***FIRST EXECUTABLE STATEMENT DSINDG
DSINDG = SIN (RADDEG*X)
C
IF (MOD(X,90.D0).NE.0.D0) RETURN
N = ABS(X)/90.D0 + 0.5D0
N = MOD (N, 2)
IF (N.EQ.0) DSINDG = 0.D0
IF (N.EQ.1) DSINDG = SIGN (1.0D0, DSINDG)
C
RETURN
END