After blinking and rubbing my eyes, I finally see what is meant by all of this. I see now that the difference is that `cumsum0()` would return a result that essentially have 0 be prepended to what would normally be the result from `cumsum()`. From the description, I thought the "problem" was that the summation starts from 1. Personally, I never really thought of cumsum() as starting from index 1, so I didn't understand the problem as stated.

So, I think some workshopping of the description is in order.

On Fri, Aug 11, 2023 at 1:53 PM Robert Kern <> wrote:
On Fri, Aug 11, 2023 at 1:47 PM Benjamin Root <> wrote:
I'm really confused. Summing from zero should be what cumsum() does now.

>>> np.__version__
>>> np.cumsum([[1, 2, 3], [4, 5, 6]])
array([ 1,  3,  6, 10, 15, 21])
which matches your example in the cumsum0() documentation. Did something change in a recent release?

That's not what's in his example.
Robert Kern
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