Error using sub2ind (line 43) Out of range subscript. How to solve this?

I have a code here that finds the data i need for specific cell values, for some reason it breaks when i get to the 27th iteration. Which to me doesn't make sense as everything should be within the desired range and the matrix dimensions agree, any help would be appreciated

PM25 Data

PM = ('C:\Users\jorda\Desktop\Physics Project\PM Dust Not Removed\ACAG_PM25_V4GL03_199801_199812_0p05.nc');

x_val = ncread(PM,'LAT');
y_val = ncread(PM,'LON');
PM_val = ncread(PM,'PM25');

S = shaperead('C:\Users\jorda\Desktop\Physics Project\filt_country.shp');

[LAT,LON]=cdtgrid([0.05 0.05]);

strc1 = struct2cell(S);
strc2 = strc1(5,:)';
st = cell2mat(strc2);

i = 1;
while i <= 51
    mat_zer=zeros(3600,7200);
    isin1 = inpolygon(LON,LAT,S(i).X,S(i).Y);
    mat_zer(isin1)=st(i);
    [row1,col1] = find(mat_zer~=0);
    mat_zer_pm = PM_val;
    inds1 = sub2ind(size(mat_zer_pm),row1,col1);
    new_mat1 = nan(size(mat_zer_pm));
    new_mat1(inds1) = mat_zer_pm(inds1);
    Country{i,2} = new_mat1;
    i = i + 1;
end

Answer 1

[Fangjun Jiang]

[row1,col1] is the index for mat_zer

in sub2ind(), it is using size(mat_zer_pm)

Do mat_zer_pm and mat_zer have the same size all the time?

[Jordan Coombs]

Ahh no i hadn't. Thank you that solved my problem!