is it possible to use numpy math function through local_dict

[westNeighbor]

I want to use numpy's math function and I try:
evaluate("log2(x)", {"log2": numpy.log2}), it gives errors.

[gdementen]

No, local_dict is only for data. Each function supported by numexpr must have specific code in the library. It would be theoretically possible to implement a mechanism to let users define custom element-wise functions, but this would probably kill performance and it does not exist at the moment.