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
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
/* classq.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int classq_(integer *n, complex *x, integer *incx, real *
scale, real *sumsq)
{
/* System generated locals */
integer i__1, i__2, i__3;
real r__1;
/* Builtin functions */
double r_imag(complex *);
/* Local variables */
integer ix;
real temp1;
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* CLASSQ returns the values scl and ssq such that */
/* ( scl**2 )*ssq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, */
/* where x( i ) = abs( X( 1 + ( i - 1 )*INCX ) ). The value of sumsq is */
/* assumed to be at least unity and the value of ssq will then satisfy */
/* 1.0 .le. ssq .le. ( sumsq + 2*n ). */
/* scale is assumed to be non-negative and scl returns the value */
/* scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ), */
/* i */
/* scale and sumsq must be supplied in SCALE and SUMSQ respectively. */
/* SCALE and SUMSQ are overwritten by scl and ssq respectively. */
/* The routine makes only one pass through the vector X. */
/* Arguments */
/* ========= */
/* N (input) INTEGER */
/* The number of elements to be used from the vector X. */
/* X (input) COMPLEX array, dimension (N) */
/* The vector x as described above. */
/* x( i ) = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. */
/* INCX (input) INTEGER */
/* The increment between successive values of the vector X. */
/* INCX > 0. */
/* SCALE (input/output) REAL */
/* On entry, the value scale in the equation above. */
/* On exit, SCALE is overwritten with the value scl . */
/* SUMSQ (input/output) REAL */
/* On entry, the value sumsq in the equation above. */
/* On exit, SUMSQ is overwritten with the value ssq . */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--x;
/* Function Body */
if (*n > 0) {
i__1 = (*n - 1) * *incx + 1;
i__2 = *incx;
for (ix = 1; i__2 < 0 ? ix >= i__1 : ix <= i__1; ix += i__2) {
i__3 = ix;
if (x[i__3].r != 0.f) {
i__3 = ix;
temp1 = (r__1 = x[i__3].r, dabs(r__1));
if (*scale < temp1) {
/* Computing 2nd power */
r__1 = *scale / temp1;
*sumsq = *sumsq * (r__1 * r__1) + 1;
*scale = temp1;
} else {
/* Computing 2nd power */
r__1 = temp1 / *scale;
*sumsq += r__1 * r__1;
}
}
if (r_imag(&x[ix]) != 0.f) {
temp1 = (r__1 = r_imag(&x[ix]), dabs(r__1));
if (*scale < temp1) {
/* Computing 2nd power */
r__1 = *scale / temp1;
*sumsq = *sumsq * (r__1 * r__1) + 1;
*scale = temp1;
} else {
/* Computing 2nd power */
r__1 = temp1 / *scale;
*sumsq += r__1 * r__1;
}
}
/* L10: */
}
}
return 0;
/* End of CLASSQ */
} /* classq_ */
|
