mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
133 lines
3.3 KiB
133 lines
3.3 KiB
#include "clapack.h" |
|
|
|
/* Subroutine */ int dlarnv_(integer *idist, integer *iseed, integer *n, |
|
doublereal *x) |
|
{ |
|
/* System generated locals */ |
|
integer i__1, i__2, i__3; |
|
|
|
/* Builtin functions */ |
|
double log(doublereal), sqrt(doublereal), cos(doublereal); |
|
|
|
/* Local variables */ |
|
integer i__; |
|
doublereal u[128]; |
|
integer il, iv, il2; |
|
extern /* Subroutine */ int dlaruv_(integer *, integer *, doublereal *); |
|
|
|
|
|
/* -- LAPACK auxiliary routine (version 3.1) -- */ |
|
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ |
|
/* November 2006 */ |
|
|
|
/* .. Scalar Arguments .. */ |
|
/* .. */ |
|
/* .. Array Arguments .. */ |
|
/* .. */ |
|
|
|
/* Purpose */ |
|
/* ======= */ |
|
|
|
/* DLARNV returns a vector of n random real numbers from a uniform or */ |
|
/* normal distribution. */ |
|
|
|
/* Arguments */ |
|
/* ========= */ |
|
|
|
/* IDIST (input) INTEGER */ |
|
/* Specifies the distribution of the random numbers: */ |
|
/* = 1: uniform (0,1) */ |
|
/* = 2: uniform (-1,1) */ |
|
/* = 3: normal (0,1) */ |
|
|
|
/* ISEED (input/output) INTEGER array, dimension (4) */ |
|
/* On entry, the seed of the random number generator; the array */ |
|
/* elements must be between 0 and 4095, and ISEED(4) must be */ |
|
/* odd. */ |
|
/* On exit, the seed is updated. */ |
|
|
|
/* N (input) INTEGER */ |
|
/* The number of random numbers to be generated. */ |
|
|
|
/* X (output) DOUBLE PRECISION array, dimension (N) */ |
|
/* The generated random numbers. */ |
|
|
|
/* Further Details */ |
|
/* =============== */ |
|
|
|
/* This routine calls the auxiliary routine DLARUV to generate random */ |
|
/* real numbers from a uniform (0,1) distribution, in batches of up to */ |
|
/* 128 using vectorisable code. The Box-Muller method is used to */ |
|
/* transform numbers from a uniform to a normal distribution. */ |
|
|
|
/* ===================================================================== */ |
|
|
|
/* .. Parameters .. */ |
|
/* .. */ |
|
/* .. Local Scalars .. */ |
|
/* .. */ |
|
/* .. Local Arrays .. */ |
|
/* .. */ |
|
/* .. Intrinsic Functions .. */ |
|
/* .. */ |
|
/* .. External Subroutines .. */ |
|
/* .. */ |
|
/* .. Executable Statements .. */ |
|
|
|
/* Parameter adjustments */ |
|
--x; |
|
--iseed; |
|
|
|
/* Function Body */ |
|
i__1 = *n; |
|
for (iv = 1; iv <= i__1; iv += 64) { |
|
/* Computing MIN */ |
|
i__2 = 64, i__3 = *n - iv + 1; |
|
il = min(i__2,i__3); |
|
if (*idist == 3) { |
|
il2 = il << 1; |
|
} else { |
|
il2 = il; |
|
} |
|
|
|
/* Call DLARUV to generate IL2 numbers from a uniform (0,1) */ |
|
/* distribution (IL2 <= LV) */ |
|
|
|
dlaruv_(&iseed[1], &il2, u); |
|
|
|
if (*idist == 1) { |
|
|
|
/* Copy generated numbers */ |
|
|
|
i__2 = il; |
|
for (i__ = 1; i__ <= i__2; ++i__) { |
|
x[iv + i__ - 1] = u[i__ - 1]; |
|
/* L10: */ |
|
} |
|
} else if (*idist == 2) { |
|
|
|
/* Convert generated numbers to uniform (-1,1) distribution */ |
|
|
|
i__2 = il; |
|
for (i__ = 1; i__ <= i__2; ++i__) { |
|
x[iv + i__ - 1] = u[i__ - 1] * 2. - 1.; |
|
/* L20: */ |
|
} |
|
} else if (*idist == 3) { |
|
|
|
/* Convert generated numbers to normal (0,1) distribution */ |
|
|
|
i__2 = il; |
|
for (i__ = 1; i__ <= i__2; ++i__) { |
|
x[iv + i__ - 1] = sqrt(log(u[(i__ << 1) - 2]) * -2.) * cos(u[( |
|
i__ << 1) - 1] * 6.2831853071795864769252867663); |
|
/* L30: */ |
|
} |
|
} |
|
/* L40: */ |
|
} |
|
return 0; |
|
|
|
/* End of DLARNV */ |
|
|
|
} /* dlarnv_ */
|
|
|