https://github.com/dell/jlt/blob/ce6963aa7207ce52390b63361b888b1e9656fb1d/linearMapping.py#L223C15-L223C15
When doing the Hadamard transform, in the implementation of fht.fht, the input array is flattened and then the hadamard transform is computed, since the default argument to axes is (0,1). However, this is not equivalent to multiplication with the hadamard matrix.