Populating an array through a loop

I am working on code that calculates grain sizes (and other things) of different mineral phases and I want it to spit out a table at the end of it with the mean, mode, etc of each phase. I am having trouble populating the "Phase List", which will be the row values of the final table. Green cells in image.

% How many unique phase IDs are in the dataset?
u = unique(grains.phase);

Unable to resolve the name 'grains.phase'.

% So how long is the list of phase ID's?
s = size(u,1);

   phaselist = zeros(s,1);
%for loop to repeat each step for each phase (starts at 2 because 1 = not
%indexed grains
  for j=2:s
    phase = grains(grains.phase==u(j)).mineral;
    
    %% calculations
    
    phaselist(j,1) = {phase}; % ERROR HERE
  end

The error I get is with the braces and it not populating the cell in phaselist with the phase, which is a character array. I have tried it several ways but get the following:

    phaselist(j,1) = {phase};
Conversion to double from cell is not possible.
    phaselist{j,1} = {phase};
Unable to perform assignment because brace indexing is not supported for variables of this type.

Any help is appreciated. Thank You.

Answer 1

[Cris LaPierre]

Why do you need to use braces at all? You create phaselist using zeros. You can assign without converting your values to cells first.

phaselist = zeros(5,1);
phase = 5;
phaselist(2,1) = phase

phaselist = 5×1

0 5 0 0 0