2.9BSD - /usr/src/lib/libF77/rand_.c

   1: /*
   2: char id_rand[] = "@(#)rand_.c	1.1";
   3:  *
   4:  * Routines to return random values
   5:  *
   6:  * calling sequence:
   7:  *	double precision d, drand
   8:  *	i = irand(iflag)
   9:  *	x = rand(iflag)
  10:  *	d = drand(iflag)
  11:  * where:
  12:  *	If arg is 1, generator is restarted. If arg is 0, next value
  13:  *	is returned. Any other arg is a new seed for the generator.
  14:  *	Integer values will range from 0 thru 2147483647.
  15:  *	Real values will range from 0.0 thru 1.0
  16:  *	(see rand(3))
  17:  */
  18: 
  19: #if vax
  20: #define RANDMAX     2147483647
  21: #else   vax
  22: #if pdp11
  23: #define RANDMAX     32767
  24: #else   pdp11
  25:     UNKNOWN MACHINE!
  26: #endif	pdp11
  27: #endif	vax
  28: 
  29: long irand_(iarg)
  30: long *iarg;
  31: {
  32:     if (*iarg) srand((int)*iarg);
  33: #if pdp11
  34:     return(( ((long)rand()) << 16) | rand());
  35: #else   pdp11
  36:     return( rand() );
  37: #endif	pdp11
  38: }
  39: 
  40: float rand_(iarg)
  41: long *iarg;
  42: {
  43:     if (*iarg) srand((int)*iarg);
  44:     return( (float)(rand())/(float)RANDMAX );
  45: }
  46: 
  47: double drand_(iarg)
  48: long *iarg;
  49: {
  50:     if (*iarg) srand((int)*iarg);
  51:     return( (double)(rand())/(double)RANDMAX );
  52: }

Defined functions

Defined macros