opt_einsum is a powerful tensor contraction order optimizer for NumPy and related ecosystems.

New Features

• Expressions can be precompiled so that the expression optimization need not happen multiple times.
• The greedy order optimization algorithm has been tuned to be able to handle hundreds of tensors in several seconds.
• Input indices can now be unicode so that expressions can have many thousands of indices.
• GPU and distributed computing backends have been added such as Dask, TensorFlow, CUPy, Theano, and Sparse.

Bug Fixes

• A error effecting cases where opt_einsum mistook broadcasting operations for matrix multiply has been fixed.
• Most error messages are now more expressive.