ODE  0.13.1
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misc.h
1 /*************************************************************************
2  * *
3  * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
4  * All rights reserved. Email: russ@q12.org Web: www.q12.org *
5  * *
6  * This library is free software; you can redistribute it and/or *
7  * modify it under the terms of EITHER: *
8  * (1) The GNU Lesser General Public License as published by the Free *
9  * Software Foundation; either version 2.1 of the License, or (at *
10  * your option) any later version. The text of the GNU Lesser *
11  * General Public License is included with this library in the *
12  * file LICENSE.TXT. *
13  * (2) The BSD-style license that is included with this library in *
14  * the file LICENSE-BSD.TXT. *
15  * *
16  * This library is distributed in the hope that it will be useful, *
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of *
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
19  * LICENSE.TXT and LICENSE-BSD.TXT for more details. *
20  * *
21  *************************************************************************/
22 
23 /* miscellaneous math functions. these are mostly useful for testing */
24 
25 #ifndef _ODE_MISC_H_
26 #define _ODE_MISC_H_
27 
28 #include <ode/common.h>
29 
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
35 
36 /* return 1 if the random number generator is working. */
37 ODE_API int dTestRand(void);
38 
39 /* return next 32 bit random number. this uses a not-very-random linear
40  * congruential method.
41  */
42 ODE_API unsigned long dRand(void);
43 
44 /* get and set the current random number seed. */
45 ODE_API unsigned long dRandGetSeed(void);
46 ODE_API void dRandSetSeed (unsigned long s);
47 
48 /* return a random integer between 0..n-1. the distribution will get worse
49  * as n approaches 2^32.
50  */
51 ODE_API int dRandInt (int n);
52 
53 /* return a random real number between 0..1 */
54 ODE_API dReal dRandReal(void);
55 
56 /* print out a matrix */
57 #ifdef __cplusplus
58 ODE_API void dPrintMatrix (const dReal *A, int n, int m, const char *fmt = "%10.4f ",
59  FILE *f=stdout);
60 #else
61 ODE_API void dPrintMatrix (const dReal *A, int n, int m, const char *fmt, FILE *f);
62 #endif
63 
64 /* make a random vector with entries between +/- range. A has n elements. */
65 ODE_API void dMakeRandomVector (dReal *A, int n, dReal range);
66 
67 /* make a random matrix with entries between +/- range. A has size n*m. */
68 ODE_API void dMakeRandomMatrix (dReal *A, int n, int m, dReal range);
69 
70 /* clear the upper triangle of a square matrix */
71 ODE_API void dClearUpperTriangle (dReal *A, int n);
72 
73 /* return the maximum element difference between the two n*m matrices */
74 ODE_API dReal dMaxDifference (const dReal *A, const dReal *B, int n, int m);
75 
76 /* return the maximum element difference between the lower triangle of two
77  * n*n matrices */
78 ODE_API dReal dMaxDifferenceLowerTriangle (const dReal *A, const dReal *B, int n);
79 
80 
81 #ifdef __cplusplus
82 }
83 #endif
84 
85 #endif