NMatrixLU

static VALUE
na_lu_solve(VALUE self, volatile VALUE other)
{
  int  n, ndim;
  int *shape;
  struct NARRAY *a1, *a2, *l, *p;
  VALUE pv, obj, klass;
  volatile VALUE lu;

  klass = CLASS_OF(other);
  if (klass==cNVector)
    other = na_newdim_ref(1,(VALUE*)na_funcset[NA_ROBJ].zero,other);
  else if (klass!=cNMatrix)
    rb_raise(rb_eTypeError,"neither NMatrix or NVector");

  lu = rb_ivar_get(self, id_lu);
  pv = rb_ivar_get(self, id_pivot);

  GetNArray(lu,l);

  other = na_upcast_object(other,l->type);
  GetNArray(other,a1);

  lu = na_upcast_type(lu,a1->type);
  GetNArray(lu,l);
  GetNArray(pv,p);

  n = l->shape[0];
  if (n != a1->shape[1])
    rb_raise(rb_eTypeError,"size mismatch (%i!=%i)",n,a1->shape[1]);

  ndim  = NA_MAX(l->rank, a1->rank);
  shape = ALLOCA_N(int, ndim);

  shape[0] = a1->shape[0];
  na_shape_max2( ndim-1, shape+1, a1->rank-1, a1->shape+1,
                 l->rank-1, l->shape+1 );
  obj = na_make_object( a1->type, ndim, shape, klass );

  GetNArray(obj,a2);

  na_exec_linalg( a2, a1, p, 2, 2, 1, na_lu_pivot_func );
  na_exec_linalg( a2, a2, l, 2, 2, 2, na_lu_solve_func );

  if (klass==cNVector) {
    shape = ALLOC_N(int, ndim-1);
    memcpy(shape,a2->shape+1,sizeof(int)*(ndim-1));
    xfree(a2->shape);
    a2->shape = shape;
    --(a2->rank);
  }
  return obj;
}