How can I calculate the iteration using the for loop function and store all iteration outputs in matrix for the big data array? Somebody please help me. Thank you.

load metals

X= (tspec)';% size X=16 x 1301 double

[m,n] = size(X);

mx    = mean(X);

x   = (X-mx(ones(m,1),:));%F represent the mean centered X data

y=tconc; % size y=16 x 4 double

k=0:0.01:1;

I=eye(size(x'*x));
b=zeros(size(x'*x));

for j=1:length(k)

      b(:,j)=((pinv(x'*x+k(j)*I))*x')*y;
  end

[Adam]

What exactly is the problem you are having? At a first glance you appear to already be storing results in an array while looping over a for loop. Are you getting an error or incorrect/unexpected results?

[Ahmad Zul Izzi Fauzi]

Hi Adam,

I got this error message:

Subscripted assignment dimension mismatch.

Error in Izzi (line 14) b(:,j)=((pinv(x'*x+k(j)*I))*x')*y;

[Adam]

Simplest thing to do is use the debugger. Put a breakpoint on the line giving the error and then put e.g.

res = ((pinv(x'*x+k(j)*I))*x')*y;
size( res )
size( b(:,j) )

on the command line. The latter two need to be the same unless res is a scalar.

I don't have all the information (e.g. metals) or the time to run your code myself so I can't see at a glance what size all the various parts of that equation are, but if you look at it on command line in a breakpoint or, if needed, break the expression into multiple variables if the error is mid expression (in this case the error is in assignment which implies the code on the right of the '=' is fine on its own, but just isn't the same size as where you are trying to assign it) it is usually very easy to find out what is wrong in these cases.

[Ahmad Zul Izzi Fauzi]

It seem the size for res is 1301 x 4 and the b(:,j) is 1301 x 1. What should I do to equal the size?

[Walter Roberson]

b(:,:,j)=((pinv(x'*x+k(j)*I))*x')*y;

The problem you are having is related to the fact that you did not define what it means to store all of the iteration results in an array. Which is a problem I mentioned in response to your previous question.

[Star Strider]

In a related Question, we solved it by correctly preallocating ‘b’.

[Ahmad Zul Izzi Fauzi]

Many thanks all. Solved.