Matrix indexing - Picking columns

So I trying to give an output a matrix which contains every fifth column of input (A). Below is what my current script look like.

function B = Script30( A )
  B = A(:,1:5:end);
end

[Birdman]

So, question?

[bondpen]

So when i input a matrix it will output only every fifth columns of input matrix.

[Guillaume]

Important difference: your code is not a script but a function. It's begging for confusion to name a function script***.

Your function already returns every fifth column of the matrix, starting at column 1, so it's not clear what problem you're having

[bondpen]

I just in habit in this naming scheme lmao.

It giving me rows instead of columns.

[Jan]

What give you rows? The shown code extracts columns.

Answer 1

[David Fletcher]

Do you mean this instead of your 1:5:end?

5:5:end

If you explicitly also want column 1 the you could use [1 5:5:end]

[bondpen]

 would like it output every 5th columns of the input. Also you second shouldn't it be something like [1,5:5:end]?

[David Fletcher]

Maybe an example of exactly what you do want is required, because I have no idea

[bondpen]

For example A is Matrix which is guaranteed to even multiple of 5 to ensure the output will have column of 5 and if it more than 5 it should give the 5th column and 10th column and vice versa.

[Jan]

@David Wu: The question is still not clear. What's wrong with David Fletcher's suggestion? It seems to do what you are asking for.

[Guillaume]

@david,

[1 5:5:end] and [1, 5:5:end] are exactly the same. In matlab, you can use a space or a comma for separating horizontal elements of a vector. Using a comma is considered safer.

[bondpen]

This works greats but the output is rows instead the desire columns.

[David Fletcher]

@Guillaume I don't dispute it. Unfortunately that's not what you've got. 1:5:end ~= 5:5:end ~= [1 5:5:end]

[bondpen]

I have replaced the code to below: It still output rows, how did you make it out columns instead?

function B = Script30( A )
  B = A(5:5:end)
end

[David Fletcher]

A(:,5:5:end);

Gives me a columnised output on my system with a test matrix

[David Fletcher]

Sorry, I meant replace the column list only, not the row indexing colon as well

[bondpen]

Yea, that does the trick. What is ":," for? Does it tell command to choose columns?

[David Fletcher]

What the first colon? It means all rows and columns 5,10,15...etc. If you don't have the first colon - as you have found - it will compact all selected columns into one row. Well that was a bit harder than it should have been, I think I need a lie down.