Getting only the odd rows of an array

[altenbach]

Yes, it depend if we do 1 based or 0 based counting. 😄

(no way to tell from the original question)

[altenbach]

Just for kicks, here are a few other ways to do it. Probably less efficient. 😉

 

[GianmarcoSbarra]

Actually even or odd doesn't matter for me, i just wanted 1 row every 2.
I'm using some image processing algorithm and it will work even with half the rows so ^^

Thanks a lot everyone

[Mythilt]

My first thought upon seeing the question was, "Why not use decimate?" then I realized that the decimate function was 1D only....still, never let such a little thing get in the way of Science!  Or more accurately, never let it get in the way of some fun and giggles.....

Not going to claim this is in anyway efficient, but was kind of fun to write.

[altenbach]

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@Mythilt wrote:

My first thought upon seeing the question was, "Why not use decimate?"

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If we want to keep the rows with even index (as in my other code), here's all we need. (And only small tweaks are needed to get the odd indices or deal with inputs containing an odd number of columns. Nothing a reshape before the decimate operation or picking the other output could't fix).

 

For some reason, I think you have way too much code. 😄

Actually this was my first idea yesterday, but I did not add it because both transpose seem to have allocation dots.

[Mythilt]

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@altenbach wrote:

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For some reason, I think you have way too much code. 😄

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Part of it was I had an initial idea, and dangnabbit, I was going to code it.  The other part is because I didn't think of that.

[altenbach]

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@Mythilt wrote:

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...s I had an initial idea, and dangnabbit, I was going to code it.  

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I know that feeling 😄