'While' loop that pulls data from a matrix with n rows

I am trying to write a code to execute a 'while' loop from a matrix. The matrix it pulls the data from ideally has n lines (where n can vary depending on the .xls file uploaded and the number of rows it contains). Variables DRb and PRb are defined earlier in the code and are constants.

[min,el]=xlsread('file name.xls');
while f<=0.04
col=4;
atom=1;

ReverseMelt(row, atom)=f;atom=atom+1;
ReverseMelt(row, atom)=((min(6,col)/(DRb+f*(1-PRb))))^(-1); col=col+1;atom=atom+1;
*many more lines of calculations*
row=row+1;
f=f+0.005;
end

The data I am looking for this calculation starts at min(6,col) but I want the while loop, when it reaches f=0.04, to start again such that min(6,col) becomes min(7,col) and so on till the end of the matrix. I have tried a 'for' loop where I put before the while loop:

x=size(min)  
y=x(1,1)

For z=6:y
while f<=0.04
col=4;
atom=1;
 ReverseMelt(row, atom)=((min(y,col)/(DRb+f*(1-PRb))))^(-1); 
end
end

I thought this would make my while loop run from row 6 in matrix min to y (the number of total rows), but didn't go. Any ideas?

Answer 1

[Roy Kadesh]

Your loop variable is z, while you use y inside your loop, so it repeats the same code y times (assuming you have hidden the code that re-initialized f for the second for-loop)

[c_def]

Ah, I see this simple mistake. However, when I insert z in the 'while' loop, I still only get the return of the first row. The code now looks like:

for z=6:y
while f<=0.04
col=4;
atom=1;
ReverseMelt(row, atom)=((min(z,col)/(DRb+f*(1-PRb))))^(-1); col=col+1;atom=atom+1;

But the matrix ReverseMelt will only have saved the loop data of the the first line in matrix min at row 6.

[Roy Kadesh]

You need to reset f, otherwise the while loop will exit immediately after the z=6 is done. You can see this if you use the debugger to step through your code.

[c_def]

Excellent, this solved it. Thanks!