SymmetrizedArray

SymmetrizedArray[{pos1 -> val1, pos2 -> val2, ...}, dims, sym] yields an array of dimensions dims whose entries are given by those in the rules posi -> vali or through the symmetry sym.

• SymmetrizedArray[list] yields a symmetrized array version of list.

Examples

SymmetrizedArray[{{1, 2} -> a, {2, 1} -> a}, {3, 3}, Symmetric[{1, 2}]]

SymmetrizedArray[{{1, 0}, {0, 1}}]

Please visit the official Wolfram Language Reference for more details.