Non-constant expression or empty matrix

Hi,

I have this error in Coder when am converting the following code, in the last line:

if ~isempty(coder.target)
    coder.varsize('lattice', [100 100]);
    lattice = zeros(0,0);
end
...
lattice = init_lattice(points,i);

if ~isempty(coder.target)
  proposed_lattice = { 0 0 0 0 };
  coder.varsize('proposed_lattice');
  energy = zeros(4);
end
    
for j=1:4
  proposed_lattice{j} = grow_lattice(lattice,points,j);
  energy(j) = lattice_energy(proposed_lattice{j},points);
end
    
[~,min_idx] = min(energy);
    
if energy(min_idx) < previous_energy
  lattice = proposed_lattice{min_idx};
...

'lattice' grows in size after each reassignment. First assignment by 'init_lattice' makes it 3*3, but as I understand, 'varsize' allows it to grow until 100*100. Would appreciate any clues.

[Walter Roberson]

I would be more comfortable if you defined energy with two parameters to zeros .zeroes(4) is 4x4 but you are assigning to it like it was 1d column vector.

[Yuri Rzhanov]

I can write

energy(j,1) = lattice_energy(proposed_lattice{j},points);
...
    if energy(min_idx,1) < previous_energy
      lattice = proposed_lattice{min_idx};
    else
        break;
    end
    

but this doesn't change anything. Checking code readiness doesn't show anything wrong, but the coder (while generating trial code) throws this error, pointing to 'min_idx' which is a scalar. 'proposed_lattice' is a cell array, so {} are suitable, right?