matrix column element limiting

hi,

I have a matrix say 200*30. I need to limit the elements of 29th and 30th columns with different constraints. how can I do that?

thanks,

Answer 1

[Azzi Abdelmalek]

Example

A=rand(200,30)
idx=A(:,29)>0.5 & A(:,30)<0.7
out=A(idx,:)

[mehrdad asadi]

thanks,

but I actually need to modify the elements!

for example if A(:,30)>1, then I should replace it with 1.

is it possible not to use 'if'?

[Azzi Abdelmalek]

You don't need a loop

idx=A(:,30)>1
A(idx,30)=1

[mehrdad asadi]

thank you A.Abdelmalek,

I did this, but because I have 4 constraints, and it should be repeated many times in a for loop, it seems it's not that much optimized! thanks anyway, right now, this is the only solution that crosses the mind.

[Stephen23]

Azzi Abdelmalek's solution is much more optimized than using a loop. This is how MATLAB works best, using basic code vectorization and indexing.