[Python-checkins] python/nondist/sandbox/twister MersenneTwister.c,1.1,1.2

2002年12月18日 09:57:09 -0800

Update of /cvsroot/python/python/nondist/sandbox/twister
In directory sc8-pr-cvs1:/tmp/cvs-serv24832
Modified Files:
	MersenneTwister.c 
Log Message:
Removed randomlist() method from interface.
Added _randbelow(n) method for fast integer generation.
Index: MersenneTwister.c
===================================================================
RCS file: /cvsroot/python/python/nondist/sandbox/twister/MersenneTwister.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -C2 -d -r1.1 -r1.2
*** MersenneTwister.c	17 Dec 2002 00:22:46 -0000	1.1
--- MersenneTwister.c	18 Dec 2002 17:57:06 -0000	1.2
***************
*** 98,109 ****
 /* Random methods */
 
! static PyObject *
! random_random(RandomObject *self)
 {
! unsigned long y, z;
 static unsigned long mag01[2]={0x0UL, MATRIX_A};
 /* mag01[x] = x * MATRIX_A for x=0,1 */
 unsigned long *mt;
- double result;
 
 mt = self->state;
--- 98,110 ----
 /* Random methods */
 
! 
! /* generates a random number on [0,0xffffffff]-interval */
! static unsigned long 
! genrand_int32(RandomObject *self)
 {
! unsigned long y;
 static unsigned long mag01[2]={0x0UL, MATRIX_A};
 /* mag01[x] = x * MATRIX_A for x=0,1 */
 unsigned long *mt;
 
 mt = self->state;
***************
*** 130,144 ****
 y ^= (y << 15) & 0xefc60000UL;
 y ^= (y >> 18);
 
! assert(N%2 == 0 && self->index < N);
! z = mt[self->index++]; /* doesn't range check. relies on N being even */
! z ^= (z >> 11);
! z ^= (z << 7) & 0x9d2c5680UL;
! z ^= (z << 15) & 0xefc60000UL;
! z ^= (z >> 18);
 result = ((y>>5)*67108864.0+(z>>6))*(1.0/9007199254740992.0);
 return PyFloat_FromDouble(result);
 }
 
 /* initializes mt[N] with a seed */
 static PyObject * 
--- 131,160 ----
 y ^= (y << 15) & 0xefc60000UL;
 y ^= (y >> 18);
+ return y;
+ }
 
! static PyObject *
! random_random(RandomObject *self)
! {
! unsigned long y, z;
! double result;
! 
! y = genrand_int32(self);
! z = genrand_int32(self);
 result = ((y>>5)*67108864.0+(z>>6))*(1.0/9007199254740992.0);
 return PyFloat_FromDouble(result);
 }
 
+ static PyObject *
+ random_randbelow(RandomObject *self, PyObject *n)
+ {
+ unsigned long limit;
+ 
+ limit = PyInt_AsLong(n);
+ if (limit == -1 && PyErr_Occurred())
+ 		return NULL;
+ return PyInt_FromLong((long)(genrand_int32(self) % limit));
+ }
+ 
 /* initializes mt[N] with a seed */
 static PyObject * 
***************
*** 317,340 ****
 }
 
- static PyObject * // XXX ? make an iterator ? remove from interface when testing is done
- random_randomlist(RandomObject *self, PyObject *cnt)
- {
- 	long count, i;
- 	PyObject *list;
- 
- 	count = PyInt_AsLong(cnt);
- 	if (count == -1 && PyErr_Occurred())
- 		return NULL;
- 	list = PyList_New((int) count);
- 	if (list == NULL)
- 		return NULL;
- 	for (i=0 ; i<count ; i++)
- 		PyList_SET_ITEM(list, i, random_random(self));
- 	return list;
- }
- 
 static PyMethodDef random_methods[] = {
 {"random", (PyCFunction)random_random, METH_NOARGS,
 		PyDoc_STR("random() -> x in the interval [0,1).")},
 {"seed",	(PyCFunction)random_seed, METH_VARARGS,
 		PyDoc_STR("seed(*seeds) -> None. Defaults to current time")},
--- 333,341 ----
 }
 
 static PyMethodDef random_methods[] = {
 {"random", (PyCFunction)random_random, METH_NOARGS,
 		PyDoc_STR("random() -> x in the interval [0,1).")},
+ {"_randbelow", (PyCFunction)random_randbelow, METH_O,
+ 		PyDoc_STR("_randbelow(n) -> integer x in the interval [0,n).")},
 {"seed",	(PyCFunction)random_seed, METH_VARARGS,
 		PyDoc_STR("seed(*seeds) -> None. Defaults to current time")},
***************
*** 346,351 ****
 		PyDoc_STR("jumpahead(int) -> None. Create a new state from\n\
 the existing state and the supplied integer.")},
- 	{"randomlist",	(PyCFunction)random_randomlist, METH_O,
- 		PyDoc_STR("randomlist(len) -> list. Return a list of random floats.")},
 	{NULL,		NULL}		/* sentinel */
 };
--- 347,350 ----