Transformation matrix for stress and strain

Transformation Matrix

transform matrix 3D-tensor (Euclidean or Cartesion tensor) of any order (>0) to another coordinate system
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% arguments: (input)
% intensor - input tensor, before transformation; should be a 3-element
% vector, a 3x3 matrix, or a 3x3x3x... multidimensional array, each
% dimension containing 3 elements.
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% Tranmatrix - transformation matrix, 3x3 matrix that contains the direction
% cosines between the old and the new coordinate system.
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% arguments: (output)
% otr - output tensor, after transformation; has the same dimensions as the input tensor.