/usr/share/doc/libsuperlu-dev/tests/MATGEN/slarnv.c is in libsuperlu3-dev 3.0+20070106-3.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | #include "f2c.h"
/* Subroutine */ int slarnv_(integer *idist, integer *iseed, integer *n, real
*x)
{
/* -- LAPACK auxiliary routine (version 2.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
SLARNV 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) REAL array, dimension (N)
The generated random numbers.
Further Details
===============
This routine calls the auxiliary routine SLARUV 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.
=====================================================================
Parameter adjustments
Function Body */
/* System generated locals */
integer i__1, i__2, i__3;
/* Builtin functions */
double log(doublereal), sqrt(doublereal), cos(doublereal);
/* Local variables */
static integer i;
static real u[128];
static integer il, iv, il2;
extern /* Subroutine */ int slaruv_(integer *, integer *, real *);
#define X(I) x[(I)-1]
#define ISEED(I) iseed[(I)-1]
i__1 = *n;
for (iv = 1; iv <= *n; 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 SLARUV to generate IL2 numbers from a uniform (0,1)
distribution (IL2 <= LV) */
slaruv_(&ISEED(1), &il2, u);
if (*idist == 1) {
/* Copy generated numbers */
i__2 = il;
for (i = 1; i <= il; ++i) {
X(iv + i - 1) = u[i - 1];
/* L10: */
}
} else if (*idist == 2) {
/* Convert generated numbers to uniform (-1,1) distribut
ion */
i__2 = il;
for (i = 1; i <= il; ++i) {
X(iv + i - 1) = u[i - 1] * 2.f - 1.f;
/* L20: */
}
} else if (*idist == 3) {
/* Convert generated numbers to normal (0,1) distributio
n */
i__2 = il;
for (i = 1; i <= il; ++i) {
X(iv + i - 1) = sqrt(log(u[(i << 1) - 2]) * -2.f) * cos(u[(i
<< 1) - 1] * 6.2831853071795864769252867663f);
/* L30: */
}
}
/* L40: */
}
return 0;
/* End of SLARNV */
} /* slarnv_ */
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