Does the standard library have a function equivalent to the following? function norm_normalize(v, p = 2) n = norm(v,p) return n, v/n end If not, is there a reason why such a function does not exist? And finally, if the function does not exist but you think that it should exist, what shoul…

I don’t know if it exists. But what is the purpose of this function? It seems trivial enough that I would write it out inline, or define my own local function. I have a similar feeling about reim, I don’t really see the point of it. Perhaps it’s very commonly used? sincos is different, since it do…

But what is the purpose of this function? Convenience. It allows you to merge two to three lines into one and avoid introducing some temporary variables. This may sound trivial, but often these things appear in quite complicated mathematical algorithms where squeezing out every bit of conciseness…

How do you make it three lines? Anyway, I’m afraid I don’t know of such a function. (I’m a bit skeptical to normalize too.)

By making v the result of some computations (e.g. a matvec A*x) which you do not want to repeat. For example, norm_normalize() would allow you to reduce v = A*x n = norm(v) v /= n to n,v = norm_normalize(A*x)

[image] DNF: (I’m a bit skeptical to normalize too.) Why?

Seems too trivial to merit it’s own name. It’s just x./norm(x), so I’m used to either writing that, or, if I need to pass it along somewhere, making an anonymous function. I don’t mind it, it just seems like something that could be trimmed away. I see it has a companion, normalize! which does sligh…

If I looked at the code for __normalize , there is more to it.

OK, good, then I guess it’s worthwhile. Since normalize / normalize! turns out to be a bit more involved than expected, perhaps the proposed function is a bit more useful than I first thought.

I am on the fence about this; it is occasionally useful but also quite easy to implement when needed, so I would tend to agree with @DNF here. Also, a = norm(v) v /= a is not much more complicated — I don’t really mind naming interim values (v = A*x), which can actually make the code cleaner. As…

Function returning normalized vector and norm

General Usage

mzaffalon June 30, 2020, 7:21am 7

Why?

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Function returning normalized vector and norm

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