how to call the vector from the work space

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Sun Heat 2019-8-25

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https://ww2.mathworks.cn/matlabcentral/answers/477481-how-to-call-the-vector-from-the-work-space

评论： Sun Heat 2019-8-26

suppose, data = [15 2 7 16 16]; and there are 16 different files in the workspace how to call it according to the 'data' vector in bunch of five(as sequence shown in data vector)

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Walter Roberson 2019-8-25

"and there are 16 different files in the workspace"

Please expand on that. Files can be on disk, but only variables can be in a workspace.

... But I suspect that the answer needed here is http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Sun Heat 2019-8-25

files is on the workspace named M1,M2,M3,M4.......upto...M16.....i have to call it according to 'data' vector.

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Answer 1

Walter Roberson 2019-8-25

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https://ww2.mathworks.cn/matlabcentral/answers/477481-how-to-call-the-vector-from-the-work-space#answer_388935

在 MATLAB Online 中打开

MS = {M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15, M16};
MS(data)

The result will be a 1 x 5 cell array that you would typically use {} indexing to access the contents of.

This code does not assume that the M variables are the same size or are the same data type.

In the case that the M variables are the same size and are a numeric data type, then there are other possibilities, such as

nd = ndims(M1);
MS = cat(nd+1, M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15, M16);
idx = [repmat({':'}, 1, nd), {data}];
MS(idx{:})

This would in this special case give you a numeric array that is one dimension higher than your original arrays, with the extra dimension corresponding to the entries in data. For example if your M variables are all 1024 x 768 x 3 RGB images, then MS would be 1024 x 768 x 3 x 16 and the indexed version would be 1024 x 768 x 3 x 5