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Diffstat (limited to 'xs/src/qhull/src/libqhull/random.c')
| -rw-r--r-- | xs/src/qhull/src/libqhull/random.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/xs/src/qhull/src/libqhull/random.c b/xs/src/qhull/src/libqhull/random.c new file mode 100644 index 000000000..176d697ae --- /dev/null +++ b/xs/src/qhull/src/libqhull/random.c @@ -0,0 +1,245 @@ +/*<html><pre> -<a href="index.htm#TOC" + >-------------------------------</a><a name="TOP">-</a> + + random.c and utilities + Park & Miller's minimimal standard random number generator + argc/argv conversion + + Used by rbox. Do not use 'qh' +*/ + +#include "libqhull.h" +#include "random.h" + +#include <string.h> +#include <stdio.h> +#include <stdlib.h> + +#ifdef _MSC_VER /* Microsoft Visual C++ -- warning level 4 */ +#pragma warning( disable : 4706) /* assignment within conditional function */ +#pragma warning( disable : 4996) /* function was declared deprecated(strcpy, localtime, etc.) */ +#endif + +/*-<a href="qh-globa.htm#TOC" + >-------------------------------</a><a name="argv_to_command">-</a> + + qh_argv_to_command( argc, argv, command, max_size ) + + build command from argc/argv + max_size is at least + + returns: + a space-delimited string of options (just as typed) + returns false if max_size is too short + + notes: + silently removes + makes option string easy to input and output + matches qh_argv_to_command_size() + + argc may be 0 +*/ +int qh_argv_to_command(int argc, char *argv[], char* command, int max_size) { + int i, remaining; + char *s; + *command= '\0'; /* max_size > 0 */ + + if (argc) { + if ((s= strrchr( argv[0], '\\')) /* get filename w/o .exe extension */ + || (s= strrchr( argv[0], '/'))) + s++; + else + s= argv[0]; + if ((int)strlen(s) < max_size) /* WARN64 */ + strcpy(command, s); + else + goto error_argv; + if ((s= strstr(command, ".EXE")) + || (s= strstr(command, ".exe"))) + *s= '\0'; + } + for (i=1; i < argc; i++) { + s= argv[i]; + remaining= max_size - (int)strlen(command) - (int)strlen(s) - 2; /* WARN64 */ + if (!*s || strchr(s, ' ')) { + char *t= command + strlen(command); + remaining -= 2; + if (remaining < 0) { + goto error_argv; + } + *t++= ' '; + *t++= '"'; + while (*s) { + if (*s == '"') { + if (--remaining < 0) + goto error_argv; + *t++= '\\'; + } + *t++= *s++; + } + *t++= '"'; + *t= '\0'; + }else if (remaining < 0) { + goto error_argv; + }else + strcat(command, " "); + strcat(command, s); + } + return 1; + +error_argv: + return 0; +} /* argv_to_command */ + +/*-<a href="qh-globa.htm#TOC" +>-------------------------------</a><a name="argv_to_command_size">-</a> + +qh_argv_to_command_size( argc, argv ) + + return size to allocate for qh_argv_to_command() + +notes: + argc may be 0 + actual size is usually shorter +*/ +int qh_argv_to_command_size(int argc, char *argv[]) { + unsigned int count= 1; /* null-terminator if argc==0 */ + int i; + char *s; + + for (i=0; i<argc; i++){ + count += (int)strlen(argv[i]) + 1; /* WARN64 */ + if (i>0 && strchr(argv[i], ' ')) { + count += 2; /* quote delimiters */ + for (s=argv[i]; *s; s++) { + if (*s == '"') { + count++; + } + } + } + } + return count; +} /* argv_to_command_size */ + +/*-<a href="qh-geom.htm#TOC" + >-------------------------------</a><a name="rand">-</a> + + qh_rand() + qh_srand( seed ) + generate pseudo-random number between 1 and 2^31 -2 + + notes: + For qhull and rbox, called from qh_RANDOMint(),etc. [user.h] + + From Park & Miller's minimal standard random number generator + Communications of the ACM, 31:1192-1201, 1988. + Does not use 0 or 2^31 -1 + this is silently enforced by qh_srand() + Can make 'Rn' much faster by moving qh_rand to qh_distplane +*/ + +/* Global variables and constants */ + +int qh_last_random= 1; /* define as global variable instead of using qh */ + +#define qh_rand_a 16807 +#define qh_rand_m 2147483647 +#define qh_rand_q 127773 /* m div a */ +#define qh_rand_r 2836 /* m mod a */ + +int qh_rand( void) { + int lo, hi, test; + int seed = qh_last_random; + + hi = seed / qh_rand_q; /* seed div q */ + lo = seed % qh_rand_q; /* seed mod q */ + test = qh_rand_a * lo - qh_rand_r * hi; + if (test > 0) + seed= test; + else + seed= test + qh_rand_m; + qh_last_random= seed; + /* seed = seed < qh_RANDOMmax/2 ? 0 : qh_RANDOMmax; for testing */ + /* seed = qh_RANDOMmax; for testing */ + return seed; +} /* rand */ + +void qh_srand( int seed) { + if (seed < 1) + qh_last_random= 1; + else if (seed >= qh_rand_m) + qh_last_random= qh_rand_m - 1; + else + qh_last_random= seed; +} /* qh_srand */ + +/*-<a href="qh-geom.htm#TOC" +>-------------------------------</a><a name="randomfactor">-</a> + +qh_randomfactor( scale, offset ) + return a random factor r * scale + offset + +notes: + qh.RANDOMa/b are defined in global.c +*/ +realT qh_randomfactor(realT scale, realT offset) { + realT randr; + + randr= qh_RANDOMint; + return randr * scale + offset; +} /* randomfactor */ + +/*-<a href="qh-geom.htm#TOC" +>-------------------------------</a><a name="randommatrix">-</a> + +qh_randommatrix( buffer, dim, rows ) + generate a random dim X dim matrix in range [-1,1] + assumes buffer is [dim+1, dim] + +returns: + sets buffer to random numbers + sets rows to rows of buffer + sets row[dim] as scratch row +*/ +void qh_randommatrix(realT *buffer, int dim, realT **rows) { + int i, k; + realT **rowi, *coord, realr; + + coord= buffer; + rowi= rows; + for (i=0; i < dim; i++) { + *(rowi++)= coord; + for (k=0; k < dim; k++) { + realr= qh_RANDOMint; + *(coord++)= 2.0 * realr/(qh_RANDOMmax+1) - 1.0; + } + } + *rowi= coord; +} /* randommatrix */ + +/*-<a href="qh-globa.htm#TOC" + >-------------------------------</a><a name="strtol">-</a> + + qh_strtol( s, endp) qh_strtod( s, endp) + internal versions of strtol() and strtod() + does not skip trailing spaces + notes: + some implementations of strtol()/strtod() skip trailing spaces +*/ +double qh_strtod(const char *s, char **endp) { + double result; + + result= strtod(s, endp); + if (s < (*endp) && (*endp)[-1] == ' ') + (*endp)--; + return result; +} /* strtod */ + +int qh_strtol(const char *s, char **endp) { + int result; + + result= (int) strtol(s, endp, 10); /* WARN64 */ + if (s< (*endp) && (*endp)[-1] == ' ') + (*endp)--; + return result; +} /* strtol */ |