: \$Id: rand.mod,v 1.4 1995/08/23 18:33:27 billl Exp \$ COMMENT \$Header: /usr/site/nrniv/local/mod/RCS/rand.mod,v 1.4 1995/08/23 18:33:27 billl Exp \$ Author: Stephen Fisher Date: December 1992 Email: fisher@james.psych.yale.edu Misc. random routines: fseed(seed) - set seed - return seed n_rand() - uniform distribution (0.0 <= rand < 1.0) fran(low, high) - returns random number between low and high u_rand() - uniform distribution (0.0 <= rand <= 1.0) norm() - gaussian distribution around 0 pois(mean) - poisson distribution poisrand(mean) - integer poisson distribution using scop ** Note that with a SUFFIX equal to "nothing" these functions do not have a suffix in hoc. Thus to call norm() in hoc use simply type "norm()" <- without the quotes. ENDCOMMENT INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} NEURON { SUFFIX nothing } VERBATIM #include #include /* #include /* contains MAXLONG */ #include /* contains MAXLONG */ /* Michael Hines fix for cygwin on mswin */ #if !defined(MAXLONG) #define MAXLONG LONG_MAX #endif /* extern double drand48(); #define random() drand48()*MAXLONG #define initstate(c1,c2,c3) srand48(c1) */ static long state2[32] = { 470594912, 650447616, 310934240, 695012864, 850358912, 61088076, 481306752, 786902080, 224042800, 805177664, 938284096, 145937936, 622867968, 160207584, 977329216, 716234240, 127727624, 415316352, 870137472, 18664444, 330872224, 93728752, 914779200, 736261248, 643647616, 755802688, 213052336, 410240448, 218974736, 109419280, 178026128, 689569664 }; ENDVERBATIM FUNCTION fseed(seed) { VERBATIM initstate((unsigned)_lseed,(char *)state2,32); _lfseed = _lseed; ENDVERBATIM } FUNCTION n_rand() { : 0.0 <= n_rand < 1.0 VERBATIM _ln_rand = ((double)random()) / (((double)MAXLONG) + 1.); ENDVERBATIM } FUNCTION fran(l, h) { : returns random number between low and high VERBATIM { int low, high; double num, imax, *getarg(); low = (int)_ll; high = (int)_lh; imax = high-low+1; /* the total number of numbers being used */ _lfran = (double)(low + (int) (imax*n_rand())); } ENDVERBATIM } FUNCTION u_rand() { : uniform distribution (0.0 <= rand <= 1.0) VERBATIM _lu_rand = (((double)random()) / ((double)MAXLONG)); ENDVERBATIM } FUNCTION norm() { : gaussian distribution around 0 VERBATIM { static int iset = 0; static float gset; float fac, r , v1, v2; double sqrt(); if (iset == 0) { do { v1 = 2.0 * n_rand() - 1.0; v2 = 2.0 * n_rand() - 1.0; r = v1 * v1 + v2 * v2; } while (r >= 1.0); fac = (float)sqrt(-2.0 * log(r) / r); gset = v1 * fac; iset = 1; _lnorm = v2 * fac; } else { iset = 0; _lnorm = (double)gset; } } ENDVERBATIM } FUNCTION pois(mean) { : poisson distribution VERBATIM _lpois = - _lmean * log(((double)random()+1.) / ((double)MAXLONG+1.)); ENDVERBATIM } FUNCTION poisint(mean) { poisint = poisrand(mean) }