DOC: How to partition domains #22375
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melissawm
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35 - How-To candidate
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| * Use `numpy.linspace` if you want the endpoint to be included in the result, or | ||
| if you are using a non-integer step size. |
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A bit of "why" is missing, maybe something like
| if you are using a non-integer step size. | |
| if you are using a non-integer step size since floating-point inaccuracies | |
| can make ``arange`` results with floating-point numbers confusing. |
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Ahh, you have this below. Maybe a "(see below)" instead?
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Looks great, thanks. Perhaps a reference to the howto could be added to the SeeAlso sections of the relevant functions? |
| array([0, 2, 4, 6, 8]) | ||
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| The arguments ``start`` and ``stop`` should be integer or real, but not | ||
| complex numbers. |
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Maybe we should mention the builtin range? real also means floats, but we want to somewhat discourage that, so I wonder if we can rephrase the sentence to do that.
| .. _how-to-partition: | ||
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| ===================================== | ||
| How to partition a domain using NumPy |
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Maybe a less mathy wording for the title is better? Something in the direction of generate regular spaced numbers using NumPy?
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| >>> np.linspace(1+1.j, 4, 5, dtype=np.complex64) | ||
| array([1. +1.j , 1.75+0.75j, 2.5 +0.5j , 3.25+0.25j, 4. +0.j ], | ||
| dtype=complex64) |
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I suspect linspace is probably commonly confusing due to problem of requiring num=n+1 compared to the division step with endpoint=True ("fencepost error"), just a thought that mentioning that might help (not sure).
| `mgrid` and `ogrid`, approximately defined as:: | ||
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| mgrid = nd_grid(sparse=False) | ||
| ogrid = nd_grid(sparse=True) |
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Maybe not mention nd_grid at all? It seems more of an implementation detail to me.
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Yeah I was conflicted here. Will remove
| ``ogrid`` | ||
| --------- | ||
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| Similar to ``numpy.mgrid``, ``numpy.ogrid`` returns a ``nd_grid`` instance, but |
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It is such an instance, but lets ignore that fact?
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| Similar to ``numpy.mgrid``, ``numpy.ogrid`` returns a ``nd_grid`` instance, but | ||
| the result is an *open* multidimensional meshgrid. This means that when it is | ||
| indexed, so that only one dimension of each returned array is greater than 1. |
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Is the "so that" to much? Might be good to add length of only one dimension (the "length") to clarify that it is not ndim. Could also add a sentence saying that this avoids repeating the data and thus saves memory (just another way to say the same thing) – which is often desirable.
Adds a how-to guide on partitioning domains with NumPy. Covers usage of
The main goal of this document is to avoid issues around usage of linspace and arange, but also to elaborate on the usage of all cited functions/tools. This is a first stab at a guide, feedback is appreciated!
Possibly, fixes #9616, #18625, #19670, #17339
Related issues: #18099, #13349, #12715, #2457, #630, #7009