/*
* call-seq:
* difcost(GSL::Matrix, GSL::Matrix) -> Float
*
* Calculates the geometric distance between two matrices
*/
static VALUE difcost_wrap(VALUE obj, VALUE matrix1, VALUE matrix2)
{
gsl_matrix *m1, *m2;
Data_Get_Struct(matrix1, gsl_matrix, m1);
Data_Get_Struct(matrix2, gsl_matrix, m2);
return rb_float_new(difcost(m1, m2));
}
static double update(gsl_matrix *v, gsl_matrix *w, gsl_matrix *h)
{
double dist = 0;
gsl_matrix *wt=NULL, *ht=NULL, *wh=NULL;
gsl_matrix *w_h=NULL, *wt_w=NULL;
gsl_matrix *wt_v = NULL;
gsl_matrix *v_ht=NULL, *wt_w_h=NULL, *w_h_ht=NULL;
wt = gsl_matrix_alloc(w->size2, w->size1);
gsl_matrix_transpose_memcpy(wt, w);
ht = gsl_matrix_alloc(h->size2, h->size1);
gsl_matrix_transpose_memcpy(ht, h);
// wt * v
wt_v = mm(wt, v);
// wt * w * h
wt_w = mm(wt, w);
wt_w_h = mm(wt_w, h);
gsl_matrix_free(wt_w);
// h = h.mul_elements(wt * v).div_elements(wt * w * h)
gsl_matrix_mul_elements(h, wt_v);
gsl_matrix_div_elements(h, wt_w_h);
gsl_matrix_free(wt_v);
gsl_matrix_free(wt_w_h);
// v * ht
v_ht = mm(v, ht);
// w * h * ht
w_h = mm(w, h);
w_h_ht = mm(w_h, ht);
gsl_matrix_free(w_h);
// w = w.mul_elements(v * ht).div_elements(w * h * ht)
gsl_matrix_mul_elements(w, v_ht);
gsl_matrix_div_elements(w, w_h_ht);
gsl_matrix_free(v_ht);
gsl_matrix_free(w_h_ht);
gsl_matrix_free(wt);
gsl_matrix_free(ht);
wh = mm(w, h);
dist = difcost(v, wh);
gsl_matrix_free(wh);
// w and h were modified in place
return dist;
}