Einstein sum einsum

numpy There is one of them. einsum, Einstein's summation , It is convenient to perform linear algebraic operations on matrices or arrays in the form of notation .

einops
einops Packages provide similar detailed interfaces to cover other operations ： Transposition 、 restore / Flattening 、 repeat / tile 、 extrusion / Cancel extrusion and reduction .

opt_einsum
opt_einsum Optimizing in a back-end independent manner is similar einsum The contraction order of the expression of .

above 3 Software packages are commonly used 3 Kind of , It is often seen in neural networks and linear algebra .