vectorize docstring example has incorrect identity

[bmcfee]

Reporting a bug

This is a documentation bug more than a functionality bug, so reproducibility does not exactly apply.

The docstring example in vectorize provides a ufunc of sum that has identity=1. I believe this should be 0 (additive identity):

numba/numba/np/ufunc/decorators.py

Lines 100 to 103 in 15e4878

	@vectorize(['float32(float32, float32)',
	'float64(float64, float64)'], identity=1)
	def sum(a, b):
	return a + b

The later example for mul correctly sets identity=1.

• I have tried using the latest released version of Numba (most recent is
  visible in the change log (https://github.com/numba/numba/blob/main/CHANGE_LOG).
• I have included a self contained code sample to reproduce the problem.
  i.e. it's possible to run as 'python bug.py'. N/A

[esc]

@bmcfee thank you for bringing this to our attention. This seems correct as the identity for addition is indeed 0.