Switching the position of matrix elements in Mathematica

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SUMMARY

This discussion focuses on the manipulation of matrix elements in Mathematica, specifically exchanging the positions of elements within a 4x4 matrix. The user provides a matrix A and seeks to swap specific elements: a12 with a21, a14 with a23, a32 with a41, and a34 with a43. A suggested solution involves using nested loops to iterate through the matrix and perform the swaps directly, resulting in the desired configuration. The final output demonstrates the successful rearrangement of the matrix elements.

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Say I have the following matrix, written in Mathematica

A := {{a11, a12, a13, a14}, {a21, a22, a23, a24}, {a31, a32, a33,
a34}, {a41, a42, a43, a44}}

I want to exchange the positions of a12 and a21, a14 and a23, a32 and a41 , a34 and a43.

Any ideas?

Thanks.
 
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Notice it you broke A into four 2x2 matricies, did a Transpose of each submatrix and reassembled the result back into a full matrix you would have what you want. But I can't think of a cute trick to split the matrix apart.

Either that or just brute force it
Code:
In[1]:= A={
   {a11, a12, a13, a14},
   {a21, a22, a23, a24},
   {a31, a32, a33, a34},
   {a41, a42, a43, a44}};
For[r=1, r<=3, r+=2,
  For[c=1, c<=3, c+=2,
   {A[[r+1, c]], A[[r, c+1]]} = {A[[r, c+1]], A[[r+1, c]]}
   ]
  ];
A

Out[3]= {
 {a11, a21, a13, a23},
 {a12, a22, a14, a24},
 {a31, a41, a33, a43},
 {a32, a42, a34, a44}}
 

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