e3181f26b1
Changed MPI routines to hypre_MPI routines. Added hypre_printf, etc. routines. Added AUTOTEST tests to look for 'int' and 'MPI_' calls. Added a new approach for the Fortran interface (not implemented everywhere yet).
141 lines
3.8 KiB
C
141 lines
3.8 KiB
C
|
|
#include "hypre_lapack.h"
|
|
#include "f2c.h"
|
|
|
|
doublereal dlanst_(char *norm, integer *n, doublereal *d__, doublereal *e)
|
|
{
|
|
/* -- LAPACK auxiliary routine (version 3.0) --
|
|
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
|
|
Courant Institute, Argonne National Lab, and Rice University
|
|
February 29, 1992
|
|
|
|
|
|
Purpose
|
|
=======
|
|
|
|
DLANST returns the value of the one norm, or the Frobenius norm, or
|
|
the infinity norm, or the element of largest absolute value of a
|
|
real symmetric tridiagonal matrix A.
|
|
|
|
Description
|
|
===========
|
|
|
|
DLANST returns the value
|
|
|
|
DLANST = ( max(abs(A(i,j))), NORM = 'M' or 'm'
|
|
(
|
|
( norm1(A), NORM = '1', 'O' or 'o'
|
|
(
|
|
( normI(A), NORM = 'I' or 'i'
|
|
(
|
|
( normF(A), NORM = 'F', 'f', 'E' or 'e'
|
|
|
|
where norm1 denotes the one norm of a matrix (maximum column sum),
|
|
normI denotes the infinity norm of a matrix (maximum row sum) and
|
|
normF denotes the Frobenius norm of a matrix (square root of sum of
|
|
squares). Note that max(abs(A(i,j))) is not a matrix norm.
|
|
|
|
Arguments
|
|
=========
|
|
|
|
NORM (input) CHARACTER*1
|
|
Specifies the value to be returned in DLANST as described
|
|
above.
|
|
|
|
N (input) INTEGER
|
|
The order of the matrix A. N >= 0. When N = 0, DLANST is
|
|
set to zero.
|
|
|
|
D (input) DOUBLE PRECISION array, dimension (N)
|
|
The diagonal elements of A.
|
|
|
|
E (input) DOUBLE PRECISION array, dimension (N-1)
|
|
The (n-1) sub-diagonal or super-diagonal elements of A.
|
|
|
|
=====================================================================
|
|
|
|
|
|
Parameter adjustments */
|
|
/* Table of constant values */
|
|
static integer c__1 = 1;
|
|
|
|
/* System generated locals */
|
|
integer i__1;
|
|
doublereal ret_val, d__1, d__2, d__3, d__4, d__5;
|
|
/* Builtin functions */
|
|
double sqrt(doublereal);
|
|
/* Local variables */
|
|
static integer i__;
|
|
static doublereal scale;
|
|
extern logical lsame_(char *, char *);
|
|
static doublereal anorm;
|
|
extern /* Subroutine */ HYPRE_Int dlassq_(integer *, doublereal *, integer *,
|
|
doublereal *, doublereal *);
|
|
static doublereal sum;
|
|
|
|
|
|
--e;
|
|
--d__;
|
|
|
|
/* Function Body */
|
|
if (*n <= 0) {
|
|
anorm = 0.;
|
|
} else if (lsame_(norm, "M")) {
|
|
|
|
/* Find max(abs(A(i,j))). */
|
|
|
|
anorm = (d__1 = d__[*n], abs(d__1));
|
|
i__1 = *n - 1;
|
|
for (i__ = 1; i__ <= i__1; ++i__) {
|
|
/* Computing MAX */
|
|
d__2 = anorm, d__3 = (d__1 = d__[i__], abs(d__1));
|
|
anorm = max(d__2,d__3);
|
|
/* Computing MAX */
|
|
d__2 = anorm, d__3 = (d__1 = e[i__], abs(d__1));
|
|
anorm = max(d__2,d__3);
|
|
/* L10: */
|
|
}
|
|
} else if (lsame_(norm, "O") || *(unsigned char *)
|
|
norm == '1' || lsame_(norm, "I")) {
|
|
|
|
/* Find norm1(A). */
|
|
|
|
if (*n == 1) {
|
|
anorm = abs(d__[1]);
|
|
} else {
|
|
/* Computing MAX */
|
|
d__3 = abs(d__[1]) + abs(e[1]), d__4 = (d__1 = e[*n - 1], abs(
|
|
d__1)) + (d__2 = d__[*n], abs(d__2));
|
|
anorm = max(d__3,d__4);
|
|
i__1 = *n - 1;
|
|
for (i__ = 2; i__ <= i__1; ++i__) {
|
|
/* Computing MAX */
|
|
d__4 = anorm, d__5 = (d__1 = d__[i__], abs(d__1)) + (d__2 = e[
|
|
i__], abs(d__2)) + (d__3 = e[i__ - 1], abs(d__3));
|
|
anorm = max(d__4,d__5);
|
|
/* L20: */
|
|
}
|
|
}
|
|
} else if (lsame_(norm, "F") || lsame_(norm, "E")) {
|
|
|
|
/* Find normF(A). */
|
|
|
|
scale = 0.;
|
|
sum = 1.;
|
|
if (*n > 1) {
|
|
i__1 = *n - 1;
|
|
dlassq_(&i__1, &e[1], &c__1, &scale, &sum);
|
|
sum *= 2;
|
|
}
|
|
dlassq_(n, &d__[1], &c__1, &scale, &sum);
|
|
anorm = scale * sqrt(sum);
|
|
}
|
|
|
|
ret_val = anorm;
|
|
return ret_val;
|
|
|
|
/* End of DLANST */
|
|
|
|
} /* dlanst_ */
|
|
|