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
|
/******************************************************************************
*
* MiXViews - an X window system based sound & data editor/processor
*
* Copyright (c) 1993, 1994 Regents of the University of California
*
* Author: Douglas Scott
* Date: December 13, 1994
*
* Permission to use, copy and modify this software and its documentation
* for research and/or educational purposes and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation. The author reserves the right to distribute this
* software and its documentation. The University of California and the author
* make no representations about the suitability of this software for any
* purpose, and in no event shall University of California be liable for any
* damage, loss of data, or profits resulting from its use.
* It is provided "as is" without express or implied warranty.
*
******************************************************************************/
/* kaiser.f -- translated by f2c (version of 16 February 1991 0:35:15).
You must link the resulting object file with the libraries:
-lf2c -lm -lc (in that order)
*/
#include "f2c.h"
/* ----------------------------------------------------------------------- */
/* SUBROUTINE: KAISER */
/* KAISER WINDOW */
/* ----------------------------------------------------------------------- */
/* Subroutine */ int kaiser_(integer *nf, real *w, integer *n, integer *ieo,
real *beta)
{
/* System generated locals */
integer i__1;
real r__1;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
static real xind;
static integer i;
static real xi, bes;
extern real ino_(real *);
/* NF = FILTER LENGTH IN SAMPLES */
/* W = WINDOW ARRAY OF SIZE N */
/* N = FILTER HALF LENGTH=(NF+1)/2 */
/* IEO = EVEN ODD INDICATOR--IEO=0 IF NF EVEN */
/* BETA = PARAMETER OF KAISER WINDOW */
/* Parameter adjustments */
--w;
/* Function Body */
bes = ino_(beta);
xind = (real) (*nf - 1) * (real) (*nf - 1);
i__1 = *n;
for (i = 1; i <= i__1; ++i) {
xi = (real) (i - 1);
if (*ieo == 0) {
xi += .5f;
}
xi = xi * 4.f * xi;
r__1 = *beta * sqrt(1.f - xi / xind);
w[i] = ino_(&r__1);
w[i] /= bes;
/* L10: */
}
return 0;
} /* kaiser_ */
/* ----------------------------------------------------------------------- */
/* FUNCTION: INO */
/* BESSEL FUNCTION FOR KAISER WINDOW */
/* ----------------------------------------------------------------------- */
real ino_(real *x)
{
/* System generated locals */
real ret_val;
/* Local variables */
static real e;
static integer i;
static real t, y, de, xi, sde;
y = *x / 2.f;
t = 1e-8f;
e = 1.f;
de = 1.f;
for (i = 1; i <= 25; ++i) {
xi = (real) i;
de = de * y / xi;
sde = de * de;
e += sde;
if (e * t - sde <= 0.f) {
goto L10;
} else {
goto L20;
}
L10:
;
}
L20:
ret_val = e;
return ret_val;
} /* ino_ */
|
