八度值尺寸

Question

I'm using Octave in c++ code. I'm trying to figure out the dimensions of every element of out

octave_value_list out = feval (q, in, 1);

I used

dim_vector x=out(0).dims();

According to dim-vector.h, it can only support up to 7 dimensions. Is there any way I can get the rows, columns and pages for every element of out ?

Answer 1

First, there is need to correct a mistake on your premises:

According to dim-vector.h, it can only support up to 7 dimensions.

Not true. What the header says is that there are constructors for only up to 7 dimensions. Above that, you'll have to increase the number of dimensions and set their lengths yourself.

Compare the following which are equivalent:

// create dim_vector for 5x5x5 array
dim_vector d1 = dim_vector (5, 5, 5);

dim_vector d2 = dim_vector ();

dim_vector d3 = d2.redim (3);
d3(2) = 5;
d2.resize (3, 5);

To generate dim_vectors above 7 dimensions, you can:

// 10 dimensional dim_vector of size 5x5x5...x5
dim_vector d = dim_vector ();
d.resize (10, 5);

See doxygen dev docs for dim_vector . They are more complete on the current development sources.

---

Now, to answer your specific question

Is there any way I can get the rows, columns and pages for every element of out?

Just index the dim_vector you get out of each octave_value in the octave_value_list

octave_value_list out = feval (q, in, 1);
for (octave_idx_type out_i = 0; out_i < out.length (); out_++)
  {
    dim_vector d = out(out_i).dims ();
    for (octave_idx_type di = 0 ; di < d.length (); di++)
      std::cout << "Length of dimension " << di << ": " << d(di) << std:endl;
  }