User-defined Functions#

  1. Show example of register_new

  2. Discuss commonality for other operators

  3. Discuss register_anonymous

Python-graphblas requires numba which enables compiling user-defined Python functions to native machine code for use by the GraphBLAS backend. This provides functions which are very performant.

Example user-defined UnaryOp:

from graphblas import unary

def force_odd_func(x):
    if x % 2 == 0:
        return x + 1
    return x

unary.register_new('force_odd', force_odd_func)

v = Vector.from_coo([0, 1, 3, 4, 5], [1, 2, 3, 8, 14])
w = v.apply(unary.force_odd).new()
w#

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1

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3

9

15

Similar methods exist for BinaryOp and IndexUnaryOp. User-defined Monoids and Semirings are constructed out of previously defined and built-in UnaryOps and BinaryOps.

Auto-registration of Lambdas#

As a convenience, any lambda expression used in place of a UnaryOp will be automatically compiled as registered anonymously.

Example lambda usage:

v.apply(lambda x: x % 5 - 2).new()

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-1

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