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#include "rb_lapack.h"
extern VOID ctbrfs_(char* uplo, char* trans, char* diag, integer* n, integer* kd, integer* nrhs, complex* ab, integer* ldab, complex* b, integer* ldb, complex* x, integer* ldx, real* ferr, real* berr, complex* work, real* rwork, integer* info);
static VALUE
rblapack_ctbrfs(int argc, VALUE *argv, VALUE self){
VALUE rblapack_uplo;
char uplo;
VALUE rblapack_trans;
char trans;
VALUE rblapack_diag;
char diag;
VALUE rblapack_kd;
integer kd;
VALUE rblapack_ab;
complex *ab;
VALUE rblapack_b;
complex *b;
VALUE rblapack_x;
complex *x;
VALUE rblapack_ferr;
real *ferr;
VALUE rblapack_berr;
real *berr;
VALUE rblapack_info;
integer info;
complex *work;
real *rwork;
integer ldab;
integer n;
integer ldb;
integer nrhs;
integer ldx;
VALUE rblapack_options;
if (argc > 0 && TYPE(argv[argc-1]) == T_HASH) {
argc--;
rblapack_options = argv[argc];
if (rb_hash_aref(rblapack_options, sHelp) == Qtrue) {
printf("%s\n", "USAGE:\n ferr, berr, info = NumRu::Lapack.ctbrfs( uplo, trans, diag, kd, ab, b, x, [:usage => usage, :help => help])\n\n\nFORTRAN MANUAL\n SUBROUTINE CTBRFS( UPLO, TRANS, DIAG, N, KD, NRHS, AB, LDAB, B, LDB, X, LDX, FERR, BERR, WORK, RWORK, INFO )\n\n* Purpose\n* =======\n*\n* CTBRFS provides error bounds and backward error estimates for the\n* solution to a system of linear equations with a triangular band\n* coefficient matrix.\n*\n* The solution matrix X must be computed by CTBTRS or some other\n* means before entering this routine. CTBRFS does not do iterative\n* refinement because doing so cannot improve the backward error.\n*\n\n* Arguments\n* =========\n*\n* UPLO (input) CHARACTER*1\n* = 'U': A is upper triangular;\n* = 'L': A is lower triangular.\n*\n* TRANS (input) CHARACTER*1\n* Specifies the form of the system of equations:\n* = 'N': A * X = B (No transpose)\n* = 'T': A**T * X = B (Transpose)\n* = 'C': A**H * X = B (Conjugate transpose)\n*\n* DIAG (input) CHARACTER*1\n* = 'N': A is non-unit triangular;\n* = 'U': A is unit triangular.\n*\n* N (input) INTEGER\n* The order of the matrix A. N >= 0.\n*\n* KD (input) INTEGER\n* The number of superdiagonals or subdiagonals of the\n* triangular band matrix A. KD >= 0.\n*\n* NRHS (input) INTEGER\n* The number of right hand sides, i.e., the number of columns\n* of the matrices B and X. NRHS >= 0.\n*\n* AB (input) COMPLEX array, dimension (LDAB,N)\n* The upper or lower triangular band matrix A, stored in the\n* first kd+1 rows of the array. The j-th column of A is stored\n* in the j-th column of the array AB as follows:\n* if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;\n* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd).\n* If DIAG = 'U', the diagonal elements of A are not referenced\n* and are assumed to be 1.\n*\n* LDAB (input) INTEGER\n* The leading dimension of the array AB. LDAB >= KD+1.\n*\n* B (input) COMPLEX array, dimension (LDB,NRHS)\n* The right hand side matrix B.\n*\n* LDB (input) INTEGER\n* The leading dimension of the array B. LDB >= max(1,N).\n*\n* X (input) COMPLEX array, dimension (LDX,NRHS)\n* The solution matrix X.\n*\n* LDX (input) INTEGER\n* The leading dimension of the array X. LDX >= max(1,N).\n*\n* FERR (output) REAL array, dimension (NRHS)\n* The estimated forward error bound for each solution vector\n* X(j) (the j-th column of the solution matrix X).\n* If XTRUE is the true solution corresponding to X(j), FERR(j)\n* is an estimated upper bound for the magnitude of the largest\n* element in (X(j) - XTRUE) divided by the magnitude of the\n* largest element in X(j). The estimate is as reliable as\n* the estimate for RCOND, and is almost always a slight\n* overestimate of the true error.\n*\n* BERR (output) REAL array, dimension (NRHS)\n* The componentwise relative backward error of each solution\n* vector X(j) (i.e., the smallest relative change in\n* any element of A or B that makes X(j) an exact solution).\n*\n* WORK (workspace) COMPLEX array, dimension (2*N)\n*\n* RWORK (workspace) REAL array, dimension (N)\n*\n* INFO (output) INTEGER\n* = 0: successful exit\n* < 0: if INFO = -i, the i-th argument had an illegal value\n*\n\n* =====================================================================\n*\n\n");
return Qnil;
}
if (rb_hash_aref(rblapack_options, sUsage) == Qtrue) {
printf("%s\n", "USAGE:\n ferr, berr, info = NumRu::Lapack.ctbrfs( uplo, trans, diag, kd, ab, b, x, [:usage => usage, :help => help])\n");
return Qnil;
}
} else
rblapack_options = Qnil;
if (argc != 7 && argc != 7)
rb_raise(rb_eArgError,"wrong number of arguments (%d for 7)", argc);
rblapack_uplo = argv[0];
rblapack_trans = argv[1];
rblapack_diag = argv[2];
rblapack_kd = argv[3];
rblapack_ab = argv[4];
rblapack_b = argv[5];
rblapack_x = argv[6];
if (argc == 7) {
} else if (rblapack_options != Qnil) {
} else {
}
uplo = StringValueCStr(rblapack_uplo)[0];
diag = StringValueCStr(rblapack_diag)[0];
if (!NA_IsNArray(rblapack_ab))
rb_raise(rb_eArgError, "ab (5th argument) must be NArray");
if (NA_RANK(rblapack_ab) != 2)
rb_raise(rb_eArgError, "rank of ab (5th argument) must be %d", 2);
ldab = NA_SHAPE0(rblapack_ab);
n = NA_SHAPE1(rblapack_ab);
if (NA_TYPE(rblapack_ab) != NA_SCOMPLEX)
rblapack_ab = na_change_type(rblapack_ab, NA_SCOMPLEX);
ab = NA_PTR_TYPE(rblapack_ab, complex*);
if (!NA_IsNArray(rblapack_x))
rb_raise(rb_eArgError, "x (7th argument) must be NArray");
if (NA_RANK(rblapack_x) != 2)
rb_raise(rb_eArgError, "rank of x (7th argument) must be %d", 2);
ldx = NA_SHAPE0(rblapack_x);
nrhs = NA_SHAPE1(rblapack_x);
if (NA_TYPE(rblapack_x) != NA_SCOMPLEX)
rblapack_x = na_change_type(rblapack_x, NA_SCOMPLEX);
x = NA_PTR_TYPE(rblapack_x, complex*);
trans = StringValueCStr(rblapack_trans)[0];
if (!NA_IsNArray(rblapack_b))
rb_raise(rb_eArgError, "b (6th argument) must be NArray");
if (NA_RANK(rblapack_b) != 2)
rb_raise(rb_eArgError, "rank of b (6th argument) must be %d", 2);
ldb = NA_SHAPE0(rblapack_b);
if (NA_SHAPE1(rblapack_b) != nrhs)
rb_raise(rb_eRuntimeError, "shape 1 of b must be the same as shape 1 of x");
if (NA_TYPE(rblapack_b) != NA_SCOMPLEX)
rblapack_b = na_change_type(rblapack_b, NA_SCOMPLEX);
b = NA_PTR_TYPE(rblapack_b, complex*);
kd = NUM2INT(rblapack_kd);
{
na_shape_t shape[1];
shape[0] = nrhs;
rblapack_ferr = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
ferr = NA_PTR_TYPE(rblapack_ferr, real*);
{
na_shape_t shape[1];
shape[0] = nrhs;
rblapack_berr = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
berr = NA_PTR_TYPE(rblapack_berr, real*);
work = ALLOC_N(complex, (2*n));
rwork = ALLOC_N(real, (n));
ctbrfs_(&uplo, &trans, &diag, &n, &kd, &nrhs, ab, &ldab, b, &ldb, x, &ldx, ferr, berr, work, rwork, &info);
free(work);
free(rwork);
rblapack_info = INT2NUM(info);
return rb_ary_new3(3, rblapack_ferr, rblapack_berr, rblapack_info);
}
void
init_lapack_ctbrfs(VALUE mLapack, VALUE sH, VALUE sU, VALUE zero){
sHelp = sH;
sUsage = sU;
rblapack_ZERO = zero;
rb_define_module_function(mLapack, "ctbrfs", rblapack_ctbrfs, -1);
}
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