inverse_permutation¶
full name: tenpy.tools.misc.inverse_permutation
parent module:
tenpy.tools.misc
type: function
-
tenpy.tools.misc.
inverse_permutation
(perm)[source]¶ reverse sorting indices.
Sort functions (as
LegCharge.sort()
) return a (1D) permutation perm array, such thatsorted_array = old_array[perm]
. This function inverts the permutation perm, such thatold_array = sorted_array[inverse_permutation(perm)]
.- Parameters
- perm1D array_like
The permutation to be reversed. Assumes that it is a permutation with unique indices. If it is,
inverse_permutation(inverse_permutation(perm)) == perm
.
- Returns
- inv_perm1D array (int)
The inverse permutation of perm such that
inv_perm[perm[j]] = j = perm[inv_perm[j]]
.