workbench/libs/mathieeedoubtrans/ieeedptan.c

   1 /*
   2     Copyright © 1995-2008, The AROS Development Team. All rights reserved.
   3     $Id: $
   4 */
   5
   6 #include "mathieeedoubtrans_intern.h"
   7
   8 /*
   9     FUNCTION
  10       Calculate the tangens of the given IEEE double precision number
  11       where y represents an angle in radians.
  12
  13     RESULT
  14       result - IEEE double precision floating point number
  15
  16     NOTES
  17
  18     EXAMPLE
  19
  20     BUGS
  21
  22     SEE ALSO
  23
  24     INTERNALS
  25
  26     HISTORY
  27 */
  28
  29 AROS_LH1(double, IEEEDPTan,
  30     AROS_LHA(double, y, D0),
  31     struct MathIeeeDoubTransBase *, MathIeeeDoubTransBase, 8, MathIeeeDoubTrans
  32 )
  33 {
  34     AROS_LIBFUNC_INIT
  35     double sn, cs;
  36
  37     cs = IEEEDPCos(y);
  38     sn = IEEEDPSin(y);
  39     if (cs == 0)
  40     {
  41         if (sn > 0)
  42         {
  43             return IEEEDPPInfty_Hi;
  44         }
  45         else
  46         {
  47             return IEEEDPPInfty_Lo;
  48         }
  49     }
  50     else
  51     {
  52         return sn/cs;
  53     }
  54
  55     AROS_LIBFUNC_EXIT
  56 }
  57