352 lines
7.8 KiB
C
352 lines
7.8 KiB
C
#include "f2c.h"
|
|
|
|
/* Subroutine */ int dpotrs_(char *uplo, integer *n, integer *nrhs,
|
|
doublereal *a, integer *lda, doublereal *b, integer *ldb, integer *
|
|
info)
|
|
{
|
|
/* -- LAPACK routine (version 2.0) --
|
|
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
|
|
Courant Institute, Argonne National Lab, and Rice University
|
|
March 31, 1993
|
|
|
|
|
|
Purpose
|
|
=======
|
|
|
|
DPOTRS solves a system of linear equations A*X = B with a symmetric
|
|
positive definite matrix A using the Cholesky factorization
|
|
A = U**T*U or A = L*L**T computed by DPOTRF.
|
|
|
|
Arguments
|
|
=========
|
|
|
|
UPLO (input) CHARACTER*1
|
|
= 'U': Upper triangle of A is stored;
|
|
= 'L': Lower triangle of A is stored.
|
|
|
|
N (input) INTEGER
|
|
The order of the matrix A. N >= 0.
|
|
|
|
NRHS (input) INTEGER
|
|
The number of right hand sides, i.e., the number of columns
|
|
of the matrix B. NRHS >= 0.
|
|
|
|
A (input) DOUBLE PRECISION array, dimension (LDA,N)
|
|
The triangular factor U or L from the Cholesky factorization
|
|
|
|
A = U**T*U or A = L*L**T, as computed by DPOTRF.
|
|
|
|
LDA (input) INTEGER
|
|
The leading dimension of the array A. LDA >= max(1,N).
|
|
|
|
B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
|
|
On entry, the right hand side matrix B.
|
|
On exit, the solution matrix X.
|
|
|
|
LDB (input) INTEGER
|
|
The leading dimension of the array B. LDB >= max(1,N).
|
|
|
|
INFO (output) INTEGER
|
|
= 0: successful exit
|
|
< 0: if INFO = -i, the i-th argument had an illegal value
|
|
|
|
=====================================================================
|
|
|
|
|
|
|
|
Test the input parameters.
|
|
|
|
|
|
Parameter adjustments
|
|
Function Body */
|
|
/* Table of constant values */
|
|
static doublereal c_b9 = 1.;
|
|
|
|
/* System generated locals */
|
|
integer i__1;
|
|
/* Local variables */
|
|
extern logical lsame_(char *, char *);
|
|
extern /* Subroutine */ int dtrsm_(char *, char *, char *, char *,
|
|
integer *, integer *, doublereal *, doublereal *, integer *,
|
|
doublereal *, integer *);
|
|
static logical upper;
|
|
extern /* Subroutine */ int xerbla_(char *, integer *);
|
|
|
|
|
|
|
|
|
|
#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]
|
|
#define B(I,J) b[(I)-1 + ((J)-1)* ( *ldb)]
|
|
|
|
*info = 0;
|
|
upper = lsame_(uplo, "U");
|
|
if (! upper && ! lsame_(uplo, "L")) {
|
|
*info = -1;
|
|
} else if (*n < 0) {
|
|
*info = -2;
|
|
} else if (*nrhs < 0) {
|
|
*info = -3;
|
|
} else if (*lda < max(1,*n)) {
|
|
*info = -5;
|
|
} else if (*ldb < max(1,*n)) {
|
|
*info = -7;
|
|
}
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_("DPOTRS", &i__1);
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*n == 0 || *nrhs == 0) {
|
|
return 0;
|
|
}
|
|
|
|
if (upper) {
|
|
|
|
/* Solve A*X = B where A = U'*U.
|
|
|
|
Solve U'*X = B, overwriting B with X. */
|
|
|
|
dtrsm_("Left", "Upper", "Transpose", "Non-unit", n, nrhs, &c_b9, &A(1,1), lda, &B(1,1), ldb);
|
|
|
|
/* Solve U*X = B, overwriting B with X. */
|
|
|
|
dtrsm_("Left", "Upper", "No transpose", "Non-unit", n, nrhs, &c_b9, &
|
|
A(1,1), lda, &B(1,1), ldb);
|
|
} else {
|
|
|
|
/* Solve A*X = B where A = L*L'.
|
|
|
|
Solve L*X = B, overwriting B with X. */
|
|
|
|
dtrsm_("Left", "Lower", "No transpose", "Non-unit", n, nrhs, &c_b9, &
|
|
A(1,1), lda, &B(1,1), ldb);
|
|
|
|
/* Solve L'*X = B, overwriting B with X. */
|
|
|
|
dtrsm_("Left", "Lower", "Transpose", "Non-unit", n, nrhs, &c_b9, &A(1,1), lda, &B(1,1), ldb);
|
|
}
|
|
|
|
return 0;
|
|
|
|
/* End of DPOTRS */
|
|
|
|
} /* dpotrs_ */
|
|
|
|
/* f2c.h -- Standard Fortran to C header file */
|
|
|
|
/** barf [ba:rf] 2. "He suggested using FORTRAN, and everybody barfed."
|
|
|
|
- From The Shogakukan DICTIONARY OF NEW ENGLISH (Second edition) */
|
|
|
|
#ifndef F2C_INCLUDE
|
|
#define F2C_INCLUDE
|
|
|
|
typedef long int integer;
|
|
typedef char *address;
|
|
typedef short int shortint;
|
|
typedef float real;
|
|
typedef double doublereal;
|
|
typedef struct { real r, i; } complex;
|
|
typedef struct { doublereal r, i; } doublecomplex;
|
|
typedef long int logical;
|
|
typedef short int shortlogical;
|
|
typedef char logical1;
|
|
typedef char integer1;
|
|
/* typedef long long longint; */ /* system-dependent */
|
|
|
|
#define TRUE_ (1)
|
|
#define FALSE_ (0)
|
|
|
|
/* Extern is for use with -E */
|
|
#ifndef Extern
|
|
#define Extern extern
|
|
#endif
|
|
|
|
/* I/O stuff */
|
|
|
|
#ifdef f2c_i2
|
|
/* for -i2 */
|
|
typedef short flag;
|
|
typedef short ftnlen;
|
|
typedef short ftnint;
|
|
#else
|
|
typedef long flag;
|
|
typedef long ftnlen;
|
|
typedef long ftnint;
|
|
#endif
|
|
|
|
/*external read, write*/
|
|
typedef struct
|
|
{ flag cierr;
|
|
ftnint ciunit;
|
|
flag ciend;
|
|
char *cifmt;
|
|
ftnint cirec;
|
|
} cilist;
|
|
|
|
/*internal read, write*/
|
|
typedef struct
|
|
{ flag icierr;
|
|
char *iciunit;
|
|
flag iciend;
|
|
char *icifmt;
|
|
ftnint icirlen;
|
|
ftnint icirnum;
|
|
} icilist;
|
|
|
|
/*open*/
|
|
typedef struct
|
|
{ flag oerr;
|
|
ftnint ounit;
|
|
char *ofnm;
|
|
ftnlen ofnmlen;
|
|
char *osta;
|
|
char *oacc;
|
|
char *ofm;
|
|
ftnint orl;
|
|
char *oblnk;
|
|
} olist;
|
|
|
|
/*close*/
|
|
typedef struct
|
|
{ flag cerr;
|
|
ftnint cunit;
|
|
char *csta;
|
|
} cllist;
|
|
|
|
/*rewind, backspace, endfile*/
|
|
typedef struct
|
|
{ flag aerr;
|
|
ftnint aunit;
|
|
} alist;
|
|
|
|
/* inquire */
|
|
typedef struct
|
|
{ flag inerr;
|
|
ftnint inunit;
|
|
char *infile;
|
|
ftnlen infilen;
|
|
ftnint *inex; /*parameters in standard's order*/
|
|
ftnint *inopen;
|
|
ftnint *innum;
|
|
ftnint *innamed;
|
|
char *inname;
|
|
ftnlen innamlen;
|
|
char *inacc;
|
|
ftnlen inacclen;
|
|
char *inseq;
|
|
ftnlen inseqlen;
|
|
char *indir;
|
|
ftnlen indirlen;
|
|
char *infmt;
|
|
ftnlen infmtlen;
|
|
char *inform;
|
|
ftnint informlen;
|
|
char *inunf;
|
|
ftnlen inunflen;
|
|
ftnint *inrecl;
|
|
ftnint *innrec;
|
|
char *inblank;
|
|
ftnlen inblanklen;
|
|
} inlist;
|
|
|
|
#define VOID void
|
|
|
|
union Multitype { /* for multiple entry points */
|
|
integer1 g;
|
|
shortint h;
|
|
integer i;
|
|
/* longint j; */
|
|
real r;
|
|
doublereal d;
|
|
complex c;
|
|
doublecomplex z;
|
|
};
|
|
|
|
typedef union Multitype Multitype;
|
|
|
|
typedef long Long; /* No longer used; formerly in Namelist */
|
|
|
|
struct Vardesc { /* for Namelist */
|
|
char *name;
|
|
char *addr;
|
|
ftnlen *dims;
|
|
int type;
|
|
};
|
|
typedef struct Vardesc Vardesc;
|
|
|
|
struct Namelist {
|
|
char *name;
|
|
Vardesc **vars;
|
|
int nvars;
|
|
};
|
|
typedef struct Namelist Namelist;
|
|
|
|
#define abs(x) ((x) >= 0 ? (x) : -(x))
|
|
#define dabs(x) (doublereal)abs(x)
|
|
#define min(a,b) ((a) <= (b) ? (a) : (b))
|
|
#define max(a,b) ((a) >= (b) ? (a) : (b))
|
|
#define dmin(a,b) (doublereal)min(a,b)
|
|
#define dmax(a,b) (doublereal)max(a,b)
|
|
|
|
/* procedure parameter types for -A and -C++ */
|
|
|
|
#define F2C_proc_par_types 1
|
|
#ifdef __cplusplus
|
|
typedef int /* Unknown procedure type */ (*U_fp)(...);
|
|
typedef shortint (*J_fp)(...);
|
|
typedef integer (*I_fp)(...);
|
|
typedef real (*R_fp)(...);
|
|
typedef doublereal (*D_fp)(...), (*E_fp)(...);
|
|
typedef /* Complex */ VOID (*C_fp)(...);
|
|
typedef /* Double Complex */ VOID (*Z_fp)(...);
|
|
typedef logical (*L_fp)(...);
|
|
typedef shortlogical (*K_fp)(...);
|
|
typedef /* Character */ VOID (*H_fp)(...);
|
|
typedef /* Subroutine */ int (*S_fp)(...);
|
|
#else
|
|
typedef int /* Unknown procedure type */ (*U_fp)();
|
|
typedef shortint (*J_fp)();
|
|
typedef integer (*I_fp)();
|
|
typedef real (*R_fp)();
|
|
typedef doublereal (*D_fp)(), (*E_fp)();
|
|
typedef /* Complex */ VOID (*C_fp)();
|
|
typedef /* Double Complex */ VOID (*Z_fp)();
|
|
typedef logical (*L_fp)();
|
|
typedef shortlogical (*K_fp)();
|
|
typedef /* Character */ VOID (*H_fp)();
|
|
typedef /* Subroutine */ int (*S_fp)();
|
|
#endif
|
|
/* E_fp is for real functions when -R is not specified */
|
|
typedef VOID C_f; /* complex function */
|
|
typedef VOID H_f; /* character function */
|
|
typedef VOID Z_f; /* double complex function */
|
|
typedef doublereal E_f; /* real function with -R not specified */
|
|
|
|
/* undef any lower-case symbols that your C compiler predefines, e.g.: */
|
|
|
|
#ifndef Skip_f2c_Undefs
|
|
#undef cray
|
|
#undef gcos
|
|
#undef mc68010
|
|
#undef mc68020
|
|
#undef mips
|
|
#undef pdp11
|
|
#undef sgi
|
|
#undef sparc
|
|
#undef sun
|
|
#undef sun2
|
|
#undef sun3
|
|
#undef sun4
|
|
#undef u370
|
|
#undef u3b
|
|
#undef u3b2
|
|
#undef u3b5
|
|
#undef unix
|
|
#undef vax
|
|
#endif
|
|
#endif
|