55 lines
2.2 KiB
C
Executable File
55 lines
2.2 KiB
C
Executable File
/* RAND.H - Interface to random number generation procedures. */
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/* Copyright (c) 1995-2012 by Radford M. Neal.
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*
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* Permission is granted for anyone to copy, use, modify, and distribute
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* these programs and accompanying documents for any purpose, provided
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* this copyright notice is retained and prominently displayed, and note
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* is made of any changes made to these programs. These programs and
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* documents are distributed without any warranty, express or implied.
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* As the programs were written for research purposes only, they have not
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* been tested to the degree that would be advisable in any important
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* application. All use of these programs is entirely at the user's own
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* risk.
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*/
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/* STATE OF RANDOM NUMBER GENERATOR. */
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#define N_tables 5 /* Number of tables of real random numbers */
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typedef struct
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{ int seed; /* Seed state derives from */
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int ptr[N_tables]; /* Pointers for tables of real random numbers */
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unsigned short state48[3]; /* State of 'rand48' pseudo-random generator */
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} rand_state;
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/* BASIC PSEUDO-RANDOM GENERATION PROCEDURES. */
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void rand_seed (int); /* Initialize current state structure by seed */
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void rand_use_state (rand_state *); /* Start using given state structure */
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rand_state *rand_get_state (void); /* Return pointer to current state */
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int rand_word (void); /* Generate random 31-bit positive integer */
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/* GENERATORS FOR VARIOUS DISTRIBUTIONS. */
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double rand_uniform (void); /* Uniform from [0,1) */
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double rand_uniopen (void); /* Uniform from (0,1) */
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int rand_int (int); /* Uniform from 0, 1, ... (n-1) */
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int rand_pickd (double *, int); /* From 0 ... (n-1), with given distribution */
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int rand_pickf (float *, int); /* Same as above, but with floats */
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void rand_permutation (int *, int); /* Random permutation */
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int rand_poisson (double); /* Poisson with given mean */
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double rand_gaussian (void); /* Gaussian with mean zero and unit variance */
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double rand_logistic (void); /* Logistic centred at zero with unit width */
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double rand_cauchy (void); /* Cauchy centred at zero with unit width */
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double rand_gamma (double); /* Gamma with given shape parameter */
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double rand_exp (void); /* Exponential with mean one */
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double rand_beta (double, double); /* Beta with given parameters */
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