MATLAB: Is this a valid expression

repmat
Hi 
offsets = [32    48    64    80    96   112];
[X,Y,Z] = ndgrid([-1, 0, 1]);
offsetArray = [Z(:), Y(:), X(:)];
offsetArray(sum( offsetArray == [0, 0, 0], 2 ) == 3, :) = [];
I'm wondering whether below is a valid expression since I see a red tilde warning sign below the left bracket after the transpose sign in below
tmpOffsets = repmat( offsets(:), [1, size( offsetArray, 1 )] )'(:);
And the error message says
tmpOffsets = repmat( offsets(:), [1, size( offsetArray, 1 )] )'(:);
Error: Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
What could possibly went wrong?

Best Answer

You can't index the output of the transpose function like that. You can either do it explicitly in multiple steps, or use the function syntax:
%option 1:
tmpOffsets = repmat( offsets(:), [1, size( offsetArray, 1 )] );
tmpOffsets = tmpOffsets';
tmpOffsets = tmpOffsets(:);
%option 2:
tmpOffsets= reshape(permute(repmat( offsets(:), [1, size( offsetArray, 1 )] ),[2 1]),[],1);
I would go for option 1, because it is much easier to see what is happening.
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