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#include "rb_lapack.h"
extern VOID dlasd4_(integer* n, integer* i, doublereal* d, doublereal* z, doublereal* delta, doublereal* rho, doublereal* sigma, doublereal* work, integer* info);
static VALUE
rblapack_dlasd4(int argc, VALUE *argv, VALUE self){
VALUE rblapack_i;
integer i;
VALUE rblapack_d;
doublereal *d;
VALUE rblapack_z;
doublereal *z;
VALUE rblapack_rho;
doublereal rho;
VALUE rblapack_delta;
doublereal *delta;
VALUE rblapack_sigma;
doublereal sigma;
VALUE rblapack_info;
integer info;
doublereal *work;
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 delta, sigma, info = NumRu::Lapack.dlasd4( i, d, z, rho, [:usage => usage, :help => help])\n\n\nFORTRAN MANUAL\n SUBROUTINE DLASD4( N, I, D, Z, DELTA, RHO, SIGMA, WORK, INFO )\n\n* Purpose\n* =======\n*\n* This subroutine computes the square root of the I-th updated\n* eigenvalue of a positive symmetric rank-one modification to\n* a positive diagonal matrix whose entries are given as the squares\n* of the corresponding entries in the array d, and that\n*\n* 0 <= D(i) < D(j) for i < j\n*\n* and that RHO > 0. This is arranged by the calling routine, and is\n* no loss in generality. The rank-one modified system is thus\n*\n* diag( D ) * diag( D ) + RHO * Z * Z_transpose.\n*\n* where we assume the Euclidean norm of Z is 1.\n*\n* The method consists of approximating the rational functions in the\n* secular equation by simpler interpolating rational functions.\n*\n\n* Arguments\n* =========\n*\n* N (input) INTEGER\n* The length of all arrays.\n*\n* I (input) INTEGER\n* The index of the eigenvalue to be computed. 1 <= I <= N.\n*\n* D (input) DOUBLE PRECISION array, dimension ( N )\n* The original eigenvalues. It is assumed that they are in\n* order, 0 <= D(I) < D(J) for I < J.\n*\n* Z (input) DOUBLE PRECISION array, dimension ( N )\n* The components of the updating vector.\n*\n* DELTA (output) DOUBLE PRECISION array, dimension ( N )\n* If N .ne. 1, DELTA contains (D(j) - sigma_I) in its j-th\n* component. If N = 1, then DELTA(1) = 1. The vector DELTA\n* contains the information necessary to construct the\n* (singular) eigenvectors.\n*\n* RHO (input) DOUBLE PRECISION\n* The scalar in the symmetric updating formula.\n*\n* SIGMA (output) DOUBLE PRECISION\n* The computed sigma_I, the I-th updated eigenvalue.\n*\n* WORK (workspace) DOUBLE PRECISION array, dimension ( N )\n* If N .ne. 1, WORK contains (D(j) + sigma_I) in its j-th\n* component. If N = 1, then WORK( 1 ) = 1.\n*\n* INFO (output) INTEGER\n* = 0: successful exit\n* > 0: if INFO = 1, the updating process failed.\n*\n* Internal Parameters\n* ===================\n*\n* Logical variable ORGATI (origin-at-i?) is used for distinguishing\n* whether D(i) or D(i+1) is treated as the origin.\n*\n* ORGATI = .true. origin at i\n* ORGATI = .false. origin at i+1\n*\n* Logical variable SWTCH3 (switch-for-3-poles?) is for noting\n* if we are working with THREE poles!\n*\n* MAXIT is the maximum number of iterations allowed for each\n* eigenvalue.\n*\n\n* Further Details\n* ===============\n*\n* Based on contributions by\n* Ren-Cang Li, Computer Science Division, University of California\n* at Berkeley, USA\n*\n* =====================================================================\n*\n\n");
return Qnil;
}
if (rb_hash_aref(rblapack_options, sUsage) == Qtrue) {
printf("%s\n", "USAGE:\n delta, sigma, info = NumRu::Lapack.dlasd4( i, d, z, rho, [:usage => usage, :help => help])\n");
return Qnil;
}
} else
rblapack_options = Qnil;
if (argc != 4 && argc != 4)
rb_raise(rb_eArgError,"wrong number of arguments (%d for 4)", argc);
rblapack_i = argv[0];
rblapack_d = argv[1];
rblapack_z = argv[2];
rblapack_rho = argv[3];
if (argc == 4) {
} else if (rblapack_options != Qnil) {
} else {
}
i = NUM2INT(rblapack_i);
if (!NA_IsNArray(rblapack_z))
rb_raise(rb_eArgError, "z (3th argument) must be NArray");
if (NA_RANK(rblapack_z) != 1)
rb_raise(rb_eArgError, "rank of z (3th argument) must be %d", 1);
n = NA_SHAPE0(rblapack_z);
if (NA_TYPE(rblapack_z) != NA_DFLOAT)
rblapack_z = na_change_type(rblapack_z, NA_DFLOAT);
z = NA_PTR_TYPE(rblapack_z, doublereal*);
if (!NA_IsNArray(rblapack_d))
rb_raise(rb_eArgError, "d (2th argument) must be NArray");
if (NA_RANK(rblapack_d) != 1)
rb_raise(rb_eArgError, "rank of d (2th argument) must be %d", 1);
if (NA_SHAPE0(rblapack_d) != n)
rb_raise(rb_eRuntimeError, "shape 0 of d must be the same as shape 0 of z");
if (NA_TYPE(rblapack_d) != NA_DFLOAT)
rblapack_d = na_change_type(rblapack_d, NA_DFLOAT);
d = NA_PTR_TYPE(rblapack_d, doublereal*);
rho = NUM2DBL(rblapack_rho);
{
na_shape_t shape[1];
shape[0] = n;
rblapack_delta = na_make_object(NA_DFLOAT, 1, shape, cNArray);
}
delta = NA_PTR_TYPE(rblapack_delta, doublereal*);
work = ALLOC_N(doublereal, (n));
dlasd4_(&n, &i, d, z, delta, &rho, &sigma, work, &info);
free(work);
rblapack_sigma = rb_float_new((double)sigma);
rblapack_info = INT2NUM(info);
return rb_ary_new3(3, rblapack_delta, rblapack_sigma, rblapack_info);
}
void
init_lapack_dlasd4(VALUE mLapack, VALUE sH, VALUE sU, VALUE zero){
sHelp = sH;
sUsage = sU;
rblapack_ZERO = zero;
rb_define_module_function(mLapack, "dlasd4", rblapack_dlasd4, -1);
}
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