could anyone help me to solve the issue

I want to run the command line iwant2=max(iwant1,[],3) with respect to iterations. I tried with the following line iwant3(it)=iwant2.But i unable to get the result.Could anyone please help me on this.

[KSSV]

prabha Kumaresan 253 questions and still you are asking basic questions. Show us the whole code.

[Rik]

Prabha, please don't wait for the first comment to be a question for context. Nearly all of the questions I've seen from you lack context. It's probably connected to one of your other questions, but we can't guess which one. You really don't make it easy for people to help you. There are some simple steps you can follow as a checklist before you post a question. Please try to follow it.

[Walter Roberson]

Are you wanting it to alter the variable name itself according to the iteration? So for the first iteration the variable is iwant1, for the second iteration it is iwant2, and so on ?

[Prabha Kumaresan]

No.I want to run the command line iwant2=max(iwant1,[],3) with respect to iteartions.

[Walter Roberson]

   iwant1 = rand(32,40,17);
   for it = 1 : 5
     iwant2 = max(iwant1, [], 3);
     iwant3(:,:,it) = iwant2;
   end

You are taking the maximum along the third dimension. That implies that iwant1 has at least 3 dimensions, and that the max() will therefore return something that is at least 2 dimensions. But you are trying to store that 2 dimensional object in a single location.

[Prabha Kumaresan]

I am getting error stating Assignment has more non-singleton rhs dimensions than non-singleton subscripts if i run the following code:

for it=1:5
iwant1(t,r,s) = sum(cell2mat(o_th(t,r,s,:)));
iwant2=max(iwant1,[],3)
iwant12(:,:,it)=iwant2
end

[Walter Roberson]

We have guided you through many questions. By now we expect that you would know that we would want to see the size() of the variables at the time the problem occurred, and we would want to know which iteration the problem occurred upon.

My suspicion is that the size of the data in your cell entries is not consistent.

[Prabha Kumaresan]

a=[2 4 6 8 10 12]
b=[25]
for it=1:5
for t = 1:length(a)
for r = 1:length(b)
q=1
c=1:a(t)
for s=1:numel(c)
o_th{t,r,s,q}=D;%D= (4.2440e+12) is 1x1 double
q=q+1;
iwant1(t,r,s) = sum(cell2mat(o_th(t,r,s,:)));
iwant2=max(iwant1,[],3);
iwant12(t,r,s,it)=iwant2
end
end
end

this was the code i am working on. when i run the code i am facing error. Could you please help me on this.

Answer 1

[Walter Roberson]

a=[2 4 6 8 10 12]
c=1:a(t)

When t is 1, that is c=1:a(1) which is c=1:2

for s=1:numel(c)

so in the first iteration, s reaches as high as 2, and

iwant1(t,r,s) = sum(cell2mat(o_th(t,r,s,:)));

makes iwant1 into a 1 x 1 x 2 array.

 iwant2=max(iwant1,[],3);

With iwant1 being 1 x 1 x 2, max() of that over the third dimension is going to give a 1 x 1 result for iwant2, and a scalar can be stored into a scalar location in

iwant12(t,r,s,it)=iwant2

Then consider when t becomes 2. The first iteration with that,

iwant1(t,r,s) = sum(cell2mat(o_th(t,r,s,:)));

is going to enlarge iwant1 from 1 x 1 x 2 into to 2 x 1 x 2 . max() of a 2 x 1 x 2 over the third dimension is going to return a 2 x 1 x 1 array, more commonly called a 2 x 1 array. And you cannot store a 2 x 1 array into a scalar location.

This is the same error we have been telling you about since... what, October or so, if not earlier?

If your different iterations are going to produce different sizes of output, then you need to use cell arrays, or you need to initialize your arrays to maximum size, initializing with a value that cannot be created otherwise, to signal locations that are "unused".

[Prabha Kumaresan]

ok.Could you help me how to initialize cell arrays to maximum size inorder to run the code with respect to iterations.

[Walter Roberson]

First I have to figure out why you are incrementing q for each iteration of s. So when r becomes greater than 1, your

o_th{t,r,s,q}=D

would skip writing to o_th{t, r, s, s} and would go directly to o_th{t, r, s, (r-1)*a(t)+s} .

You indexing does not currently make sense to me.

[Stephen23]

@Prabha Kumaresan: you need to learn how to debug your own code. In the long run, debugging code using random strangers on the internet is not an efficient use of your time. The first things to check when code does not work are what sizes variables have, what values variables have, what classes variables have, and to check if these are appropriate for where the code fails. After using MATLAB for so long, I am sure that you could check these things yourself.

[Rik]

You should also seriously consider a course with a paid instructor. I'm suggesting a paid instructor, because they should have the time to help you individually, and focus on what are the parts that are difficult for you.