imageData=[]; % set up an empty array
imSize=100;
numRows=imSize;
numCols=imSize;
%populate using a nested loop
for row=[numRows:-1:1]
imageRow=[]; %empty vector for row
for col=[numCols:-1:1]
pixelVal=(col+row)/(imSize*2); % make a pixel val in 0..1
imageRow=[imageRow pixelVal]; %add value for pixel
end
imageData=[imageData; imageRow]; % add row of pixels
end
for row=[1:numRows]
imageRow=[]; %empty vector for row
for col=[numCols:-1:1]
pixelVal=(col+row)/(imSize*2); % make a pixel val in 0..1
imageRow=[imageRow pixelVal]; %add value for pixel
end
imageData=[imageData; imageRow]; % add row of pixels
end
for row=[numRows:-1:1]
imageRow=[]; %empty vector for row
for col=[1:numCols]
pixelVal=(col+row)/(imSize*2); % make a pixel val in 0..1
imageRow=[imageRow pixelVal]; %add value for pixel
end
imageData=[imageData; imageRow]; % add row of pixels
end
for row=[1:numRows]
imageRow=[]; %empty vector for row
for col=[1:numCols]
pixelVal=(col+row)/(imSize*2); % make a pixel val in 0..1
imageRow=[imageRow pixelVal ]; %add value for pixel
end
imageData=[imageData;imageRow]; % add row of pixels
end
% display as an image
imshow(imageData);
but i want this picture like 
