projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| d8f9b501 | 1 | /* |
| be6e3ddf RE |
2 | * Copyright (c) 1980 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement | |
| 4 | * specifies the terms and conditions for redistribution. | |
| d8f9b501 | 5 | * |
| 1c15e888 | 6 | * @(#)rand_.c 5.4 5/13/90 |
| eda8efe9 | 7 | * |
| d8f9b501 DW |
8 | * Routines to return random values |
| 9 | * | |
| 10 | * calling sequence: | |
| 11 | * double precision d, drand | |
| 12 | * i = irand(iflag) | |
| 13 | * x = rand(iflag) | |
| 14 | * d = drand(iflag) | |
| 15 | * where: | |
| 16 | * If arg is 1, generator is restarted. If arg is 0, next value | |
| 17 | * is returned. Any other arg is a new seed for the generator. | |
| 18 | * Integer values will range from 0 thru 2147483647. | |
| 19 | * Real values will range from 0.0 thru 1.0 | |
| 20 | * (see rand(3)) | |
| 21 | */ | |
| 22 | ||
| 02188c47 | 23 | #if defined(vax) || defined(tahoe) || defined(hp300) |
| d8f9b501 | 24 | #define RANDMAX 2147483647 |
| d008ac38 | 25 | #else vax || tahoe |
| d8f9b501 DW |
26 | #if pdp11 |
| 27 | #define RANDMAX 32767 | |
| 28 | #else pdp11 | |
| 29 | UNKNOWN MACHINE! | |
| 30 | #endif pdp11 | |
| d008ac38 | 31 | #endif vax || tahoe |
| d8f9b501 DW |
32 | |
| 33 | long irand_(iarg) | |
| 34 | long *iarg; | |
| 35 | { | |
| 36 | if (*iarg) srand((int)*iarg); | |
| 37 | #if pdp11 | |
| 38 | return(( ((long)rand()) << 16) | rand()); | |
| 39 | #else pdp11 | |
| 40 | return( rand() ); | |
| 41 | #endif pdp11 | |
| 42 | } | |
| 43 | ||
| 44 | float rand_(iarg) | |
| 45 | long *iarg; | |
| 46 | { | |
| 47 | if (*iarg) srand((int)*iarg); | |
| 48 | return( (float)(rand())/(float)RANDMAX ); | |
| 49 | } | |
| 50 | ||
| 51 | double drand_(iarg) | |
| 52 | long *iarg; | |
| 53 | { | |
| 54 | if (*iarg) srand((int)*iarg); | |
| 55 | return( (double)(rand())/(double)RANDMAX ); | |
| 56 | } |