FOR LOOP WITH CELLS: Index exceeds the number of array elements. Index must not exceed 3.

Dearest,

I am unable to solve this error.

I have to compute the mean of voxel, of three lesions(nameLesion_list), in six different "brain maps"(nameMaps_list).

When I run the for loop my command window shows: "Index exceeds the number of array elements. Index must not exceed 3".

I understand that is for the nameLesion_list that is array of three elements but I don't know how I can operate differently with it.

Thank you for your help.

nameLesion_list={lesion_mask_TP0,lesion_mask_TP1,lesion_mask_TP2};

nameMaps_list={mtr_TP0,mtr_TP1,mtr_TP2,mtsat_TP0,mtsat_TP1,mtsat_TP2};

maps_list={mtr_T0_labels,mtr_T1_labels,mtr_T2_labels,mtsat_T0_labels,mtsat_T1_labels,mtsat_T2_labels};

for i_maps=1:length(maps_list)

temp_map=maps_list{i_maps};

temp_nameMap=nameMaps_list{i_maps};

temp_nameLesion=nameLesion_list{i_maps};

[mean_map_lesion,std_map_lesion]=mean_std_map_x_ROI_accorpate(temp_nameMap,temp_nameLesion,ROI_labels.CellLabelNumber);

T_mean_maps.(['mean_' temp_map])=mean_map_lesion(:);

T_std_maps.(['std_' temp_map])=std_map_lesion(:);

end

Answer 1

[LeoAiE]

The issue occurs because you are using the same index i_maps to access both nameMaps_list and nameLesion_list. Since nameMaps_list has six elements and nameLesion_list has only three, the index exceeds the number of elements in nameLesion_list.

To fix this, you can use the modulo operator to loop through the nameLesion_list. Here's the corrected code:

nameLesion_list = {lesion_mask_TP0, lesion_mask_TP1, lesion_mask_TP2};
nameMaps_list = {mtr_TP0, mtr_TP1, mtr_TP2, mtsat_TP0, mtsat_TP1, mtsat_TP2};
maps_list = {mtr_T0_labels, mtr_T1_labels, mtr_T2_labels, mtsat_T0_labels, mtsat_T1_labels, mtsat_T2_labels};

for i_maps = 1:length(maps_list)
    temp_map = maps_list{i_maps};
    temp_nameMap = nameMaps_list{i_maps};

    % Use modulo operator to loop through the nameLesion_list
    temp_nameLesion = nameLesion_list{mod(i_maps - 1, length(nameLesion_list)) + 1};

    [mean_map_lesion, std_map_lesion] = mean_std_map_x_ROI_accorpate(temp_nameMap, temp_nameLesion, ROI_labels.CellLabelNumber);
    T_mean_maps.(['mean_' temp_map]) = mean_map_lesion(:);
    T_std_maps.(['std_' temp_map]) = std_map_lesion(:);
end

By using the modulo operator, the index will loop through the nameLesion_list while iterating through the nameMaps_list. This way, the index will not exceed the number of array elements in nameLesion_list.

[franzin_r]

Thank you, really helpful!