/* See stmatrix.h */
/* Last edited on 2003-08-29 02:07:06 by stolfi */

#include <stmatrix.h>

#include <js.h>
#include <fget.h>
#include <nget.h>

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <values.h>

/* IMPLEMENTATIONS */

Matrix st_read_Matrix(char *name)
  { affirm(name != NULL, "no file name given");
    affirm(strlen(name) != 0, "empty file name");
    FILE *rd = (strcmp(name, "-") == 0 ? stdin : open_read(name));
    Matrix M = st_fread_Matrix(rd);
    if (rd != stdin) { fclose(rd); }
    return M;
  }
  
Matrix st_fread_Matrix(FILE *rd)
  { int nel = nget_int(rd, "elems"); fget_eol(rd);
    Matrix M = Matrix_new(nel);
    int i;
    for (i = 0; i < nel; i++) 
      { MatEntry *e = &(M.el[i]);
        e->row = fget_int(rd);
        e->col = fget_int(rd);
        e->val = fget_double(rd);
        fget_eol(rd);
      }
    return M;
  }
  
void st_write_Matrix(char *name, Matrix M)
  { affirm(name != NULL, "no file name given");
    affirm(strlen(name) != 0, "empty file name");
    FILE *wr = (strcmp(name, "-") == 0 ? stdout : open_write(name));
    st_fwrite_Matrix(wr, M);
    if (wr != stdout) { fclose(wr); }
  }

void st_fwrite_Matrix(FILE *wr, Matrix M)
  { int i;
    fprintf(wr, "elems = %d\n", M.nel);
    for (i = 0; i < M.nel; i++) 
      { MatEntry *e = &(M.el[i]);
        fprintf(wr, "%5d %5d %24.16e\n", e->row, e->col, e->val); }
    fflush(wr);
  }

Matrix Matrix_new(nat nel)
  { /* This is not a macro only because gcc does not allow cast of struct: */
    vec_t v = vec_new(nel, sizeof(MatEntry));
    Matrix r;
    r.nel = v.nel; r.el = (MatEntry *)v.el;
    return r;
  }