Loop problem

Hello, I have a loop problem in Matlab

Consider the following datasets:

models = 5x10 (5 rows, 10 columns)

bsdata = 5x20 (5 rows, 20 columns)

I want to do the following calculation:

Result=models(bsdata);

If I do so, I obtain a 5x20 dataset. How can I do this for all the 10 columns of models? I would like to obtain a 10x200 dataset? I have tried the following, but it doesn’t work:

for i=1:10

Result=models(:,i)(bsdata);

end

Thanks,

Pieter

[Fangjun Jiang]

what do you mean by Result=models(bsdata) since models and bsdata are matrix. What operation do you want to do to obtain the results?

[Charles]

Hi,

your question is confusing and maybe you should frame it better.

models = ones(5, 10); %gives a 5 x 10 matrix

bsdata =zeros(5, 20): % 5 x 20 matrix

Result=models(bsdata); %Are not possible, bsdata is larger than models

Result=bsdata(models);%Possible. References bsdata indexed by models.

for i=1:10

Result=models(:,i)(bsdata);

end

This part is not really clear. I think it is better you rather clarify what you mean with words.

[Pieter]

I try to explain it: bsdata is a dataset that picks random numbers from models. So if bsdata has the number 3, this means that it takes the third element from models. So if I do Results=models(bsdata), results will take the third number from models.

A short example:

models = [3;8;7;6]

bsdata = [2;2;1;4, 3;4;2;1]

If you do: result=models(bsdata);

result = [8;8;3;6, 7;6;8;3]

I hope this makes it more clear.

The problem I have is that he only does this calculation for the first column of models, and not for column 2-10.

[Pieter]

@ Charles, you are right, my example is not correct. Instead of models being a 5x10 matrix, make it a 5x30 matrix, than it should work (I think)

[Oleg Komarov]

Still not clear why you have a matrix for bsdata instead of a vector. How are you gonna draw a 5 by 20 matrix from a 5 by 30?

[Pieter]

You are right, it are vectors. I was using the wrong word.

Answer 1

[Oleg Komarov]

Then:

Result = models(bsdata,:);

You will draw rows direclty fro models.

[Pieter]

Thanks!