Merge pull request #168 from mehlis/random

add mersenne twister

sys/Makefile

@@ -79,6 +79,9 @@ endif
 ifneq (,$(findstring crypto,$(USEMODULE)))
     DIRS += crypto
 endif
+ifneq (,$(findstring random,$(USEMODULE)))
+    DIRS += random
+endif
 
 all: $(BINDIR)$(MODULE).a 
 	@for i in $(DIRS) ; do $(MAKE) -C $$i ; done ;

sys/include/random.h

@@ -0,0 +1,59 @@
+#include <inttypes.h>
+
+#ifndef PRNG_FLOAT
+#  define PRNG_FLOAT (0)
+#endif
+
+/**
+ * @brief initializes mt[N] with a seed
+ *
+ * @param s seed for the PRNG
+ */
+void genrand_init(uint32_t s);
+
+/**
+ * @brief initialize by an array with array-length
+ * init_key is the array for initializing keys
+ * key_length is its length
+ * slight change for C++, 2004/2/26
+ *
+ * @param init_key array of keys (seeds) to initialize the PRNG
+ * @param key_length number of lements in init_key
+ */
+void genrand_init_by_array(uint32_t init_key[], int key_length);
+
+/**
+ * @brief generates a random number on [0,0xffffffff]-interval
+ * @return a random number on [0,0xffffffff]-interval
+ */
+uint32_t genrand_uint32(void);
+
+
+#if PRNG_FLOAT
+/* These real versions are due to Isaku Wada, 2002/01/09 added */
+
+/**
+ * @brief generates a random number on [0,1)-real-interval
+ * @return a random number on [0,1)-real-interval
+ */
+double genrand_real(void);
+
+/**
+ * @brief generates a random number on [0,1]-real-interval
+ * @return a random number on [0,1]-real-interval
+ */
+double genrand_real_inclusive(void);
+
+/**
+ * @brief generates a random number on (0,1)-real-interval
+ * @return a random number on (0,1)-real-interval
+ */
+double genrand_real_exclusive(void);
+
+/**
+ * @brief generates a random number on [0,1) with 53-bit resolution
+ * @return a random number on [0,1) with 53-bit resolution
+ */
+double genrand_res53(void);
+
+#endif /* PRNG_FLOAT */

sys/random/Makefile

@@ -0,0 +1,5 @@
+INCLUDES = -I../include -I$(RIOTBASE)/core/include
+MODULE = random
+
+include $(RIOTBASE)/Makefile.base
+

sys/random/mersenne.c

@@ -0,0 +1,165 @@
+/*
+ A C-program for MT19937, with initialization improved 2002/1/26.
+ Coded by Takuji Nishimura and Makoto Matsumoto.
+
+ Before using, initialize the state by using init_genrand(seed)
+ or init_by_array(init_key, key_length).
+
+ Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ 3. The names of its contributors may not be used to endorse or promote
+ products derived from this software without specific prior written
+ permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+ Any feedback is very welcome.
+ http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
+ email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
+ */
+
+#include "random.h"
+
+/** Period parameters */
+#define N 624
+#define M 397
+#define MATRIX_A 0x9908b0dfUL   /** constant vector a */
+#define UPPER_MASK 0x80000000UL /** most significant w-r bits */
+#define LOWER_MASK 0x7fffffffUL /** least significant r bits */
+
+#define MTI_UNINITIALIZED (N + 1)
+
+static uint32_t mt[N]; /** the array for the state vector  */
+static uint16_t mti = MTI_UNINITIALIZED;
+
+void genrand_init(uint32_t s)
+{
+    mt[0] = s;
+    for (int i = 1; i < N; ++i) {
+        mt[i] = 1812433253UL * (mt[i - 1] ^ (mt[i - 1] >> 30)) + i;
+        /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
+        /* In the previous versions, MSBs of the seed affect   */
+        /* only MSBs of the array mt[].                        */
+        /* 2002/01/09 modified by Makoto Matsumoto             */
+    }
+
+    mti = N;
+}
+
+void genrand_init_by_array(uint32_t *init_key, int key_length)
+{
+    genrand_init(19650218UL);
+    int i = 1;
+    int j = 0;
+    for (int k = N > key_length ? N : key_length; k; --k) {
+        mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525UL))
+                + init_key[j] + j; /* non linear */
+        ++i;
+        ++j;
+        if (i >= N) {
+            mt[0] = mt[N - 1];
+            i = 1;
+        }
+        if (j >= key_length) {
+            j = 0;
+        }
+    }
+    for (int k = N - 1; k; k--) {
+        mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941UL)) - i; /* non linear */
+        i++;
+        if (i >= N) {
+            mt[0] = mt[N - 1];
+            i = 1;
+        }
+    }
+
+    mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
+}
+
+/** generates N words at one time */
+static void generate_numbers(void)
+{
+    if (mti == MTI_UNINITIALIZED) {
+        /* if init_genrand() has not been called, a default initial seed is used */
+        genrand_init(5489UL);
+    }
+
+    for (int k = 0; k < N; ++k) {
+        uint32_t y = (mt[k] & UPPER_MASK) | (mt[(k + 1) % N] & LOWER_MASK);
+        mt[k] = mt[(k + M) % N] ^ (y >> 1);
+        if (y & 1) {
+            mt[k] ^= MATRIX_A;
+        }
+    }
+
+    mti = 0;
+}
+
+uint32_t genrand_uint32(void)
+{
+    if (mti >= N) {
+        generate_numbers();
+    }
+
+    uint32_t y = mt[mti++];
+    y ^= y >> 11;
+    y ^= (y << 7) & 0x9d2c5680UL;
+    y ^= (y << 15) & 0xefc60000UL;
+    y ^= y >> 18;
+    return y;
+}
+
+#if PRNG_FLOAT
+
+#define TWO_POW_6 64.0
+#define TWO_POW_26 67108864.0
+#define TWO_POW_32_M1 4294967295.0
+#define TWO_POW_32 4294967296.0
+#define TWO_POW_53 9007199254740992.0
+
+double genrand_real(void)
+{
+    return genrand_uint32() * (1.0 / TWO_POW_32);
+}
+
+double genrand_real_inclusive(void)
+{
+    return genrand_uint32() * (1.0 / TWO_POW_32_M1);
+}
+
+double genrand_real_exclusive(void)
+{
+    return ((double) genrand_uint32() + 0.5) * (1.0 / TWO_POW_32);
+}
+
+double genrand_res53(void)
+{
+    double a = genrand_uint32() * TWO_POW_26;
+    double b = genrand_uint32() * (1.0 / TWO_POW_6);
+    return (a + b) * (1.0 / TWO_POW_53);
+}
+
+#endif /* PRNG_FLOAT */