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#include "rb_lapack.h"
extern VOID spoequb_(integer* n, real* a, integer* lda, real* s, real* scond, real* amax, integer* info);
static VALUE
rblapack_spoequb(int argc, VALUE *argv, VALUE self){
VALUE rblapack_a;
real *a;
VALUE rblapack_s;
real *s;
VALUE rblapack_scond;
real scond;
VALUE rblapack_amax;
real amax;
VALUE rblapack_info;
integer info;
integer lda;
integer n;
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 s, scond, amax, info = NumRu::Lapack.spoequb( a, [:usage => usage, :help => help])\n\n\nFORTRAN MANUAL\n SUBROUTINE SPOEQUB( N, A, LDA, S, SCOND, AMAX, INFO )\n\n* Purpose\n* =======\n*\n* SPOEQU computes row and column scalings intended to equilibrate a\n* symmetric positive definite matrix A and reduce its condition number\n* (with respect to the two-norm). S contains the scale factors,\n* S(i) = 1/sqrt(A(i,i)), chosen so that the scaled matrix B with\n* elements B(i,j) = S(i)*A(i,j)*S(j) has ones on the diagonal. This\n* choice of S puts the condition number of B within a factor N of the\n* smallest possible condition number over all possible diagonal\n* scalings.\n*\n\n* Arguments\n* =========\n*\n* N (input) INTEGER\n* The order of the matrix A. N >= 0.\n*\n* A (input) REAL array, dimension (LDA,N)\n* The N-by-N symmetric positive definite matrix whose scaling\n* factors are to be computed. Only the diagonal elements of A\n* are referenced.\n*\n* LDA (input) INTEGER\n* The leading dimension of the array A. LDA >= max(1,N).\n*\n* S (output) REAL array, dimension (N)\n* If INFO = 0, S contains the scale factors for A.\n*\n* SCOND (output) REAL\n* If INFO = 0, S contains the ratio of the smallest S(i) to\n* the largest S(i). If SCOND >= 0.1 and AMAX is neither too\n* large nor too small, it is not worth scaling by S.\n*\n* AMAX (output) REAL\n* Absolute value of largest matrix element. If AMAX is very\n* close to overflow or very close to underflow, the matrix\n* should be scaled.\n*\n* INFO (output) INTEGER\n* = 0: successful exit\n* < 0: if INFO = -i, the i-th argument had an illegal value\n* > 0: if INFO = i, the i-th diagonal element is nonpositive.\n*\n\n* =====================================================================\n*\n\n");
return Qnil;
}
if (rb_hash_aref(rblapack_options, sUsage) == Qtrue) {
printf("%s\n", "USAGE:\n s, scond, amax, info = NumRu::Lapack.spoequb( a, [:usage => usage, :help => help])\n");
return Qnil;
}
} else
rblapack_options = Qnil;
if (argc != 1 && argc != 1)
rb_raise(rb_eArgError,"wrong number of arguments (%d for 1)", argc);
rblapack_a = argv[0];
if (argc == 1) {
} else if (rblapack_options != Qnil) {
} else {
}
if (!NA_IsNArray(rblapack_a))
rb_raise(rb_eArgError, "a (1th argument) must be NArray");
if (NA_RANK(rblapack_a) != 2)
rb_raise(rb_eArgError, "rank of a (1th argument) must be %d", 2);
lda = NA_SHAPE0(rblapack_a);
n = NA_SHAPE1(rblapack_a);
if (NA_TYPE(rblapack_a) != NA_SFLOAT)
rblapack_a = na_change_type(rblapack_a, NA_SFLOAT);
a = NA_PTR_TYPE(rblapack_a, real*);
{
na_shape_t shape[1];
shape[0] = n;
rblapack_s = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
s = NA_PTR_TYPE(rblapack_s, real*);
spoequb_(&n, a, &lda, s, &scond, &amax, &info);
rblapack_scond = rb_float_new((double)scond);
rblapack_amax = rb_float_new((double)amax);
rblapack_info = INT2NUM(info);
return rb_ary_new3(4, rblapack_s, rblapack_scond, rblapack_amax, rblapack_info);
}
void
init_lapack_spoequb(VALUE mLapack, VALUE sH, VALUE sU, VALUE zero){
sHelp = sH;
sUsage = sU;
rblapack_ZERO = zero;
rb_define_module_function(mLapack, "spoequb", rblapack_spoequb, -1);
}
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