How to removed the ??? Reference to non-existent field error

function bgs = ComputeSilhouettes_ABC2(frame,img)

global PRM; persistent BG_STATS LAST_SEQ;

if isempty(LAST_SEQ), LAST_SEQ = -1; end

if PRM.SEQ ~= LAST_SEQ fprintf('Loading background statistics '); tic;

    SN  = get(PRM.datasetObj,'SubjectName'); SN = SN{1};

    global ABC2_DATASET_BASE_PATH;
    bgModelPath = [ABC2_DATASET_BASE_PATH '/' SN ...
        '/Background/Background_(%s).mat'];

    for V = 1 : numel(PRM.CAMS)
        % load bg_means and bg_vars
        BG_STATS{V} = load(sprintf(bgModelPath,...
            PRM.CAMS{V}.name),'bg_means','bg_vars');
        for M = 1 : numel(BG_STATS{V}.bg_means)
            ind = find(BG_STATS{V}.bg_vars{M} == 0.1);
            BG_STATS{V}.bg_vars{M}(ind) = 1.0000e-003;
        end
    end

??? Reference to non-existent field 'bg_means'.

Error in ==> ComputeSilhouettes_ABC2 at 28 for M = 1 : numel(BG_STATS{V}.bg_means)

Error in ==> LoadFrame at 61 bgs = ComputeSilhouettes_ABC2(frame,img);

Answer 1

[Image Analyst]

Why are you making it a cell array? Will you need all of them after the loop has finished? If not, then get rid of the braces and have it be just a normal structure. Then use fieldnames() to see what fields it has.

[Sanjay Saini]

Your suggestion is correct but actually i need all of them after loop.

[Image Analyst]

Try

thisBG = load(sprintf...............
BG_STATS{V} = thisBG;
fieldnames(thisBG);
bg_means = thisBG.bg_means;

[Sanjay Saini]

Thank you sir problem has been solved

Answer 2

[Roberto]

this only means that variable 'bg_means' doesn't exist in your file:

sprintf(bgModelPath,PRM.CAMS{V}.name)

[Sanjay Saini]

Respected Roberto, bg_means is available in my path directory which i have given as: bgModelPath = [ABC2_DATASET_BASE_PATH '/' SN ... '/Background/Background_(%s).mat']; Both variable 'bg_means' and 'bg_vars' is available inside Background_(%s).mat file and this file path i have given as: bgModelPath = [ABC2_DATASET_BASE_PATH '/' SN ... '/Background/Background_(%s).mat']; But in path directory have 4 camera Background (Background_(C1).mat, Background_(C2).mat, Background_(C3).mat, Background_(C4).mat) and each one contain 'bg_means' and 'bg_vars' so should i give each camera background path??