I would like to evaluate a function for N=11,21,51,and 101 using a for loop, but I can only get it to do the last N.

I tried to loop over N and get four vectors out of the function. N is the number of points and the function evaluates an estimate for the derivatives at those points. So if there are N=11 points it will give me a vector of 11 derivative estimates. I need to do this for N=11,21,51,and 101 so i was trying to loop over these N's to do this at the same time. Unfortunately, it only gives the estimates for the last N and I cannot figure out how to store the other estimates as the loop goes along. I know I can just write four separate lines of could and get these values but I was trying to condense the code. My code below only gives the N=101 estimate. Is there any way of doing this and store the information as it goes.

for N= [11,21,51,101] 
  df=fowarddif(N);
end

I tried many things, like if statements, but that ends up being more code than just the four lines. Any help would be greatly appreciated.

Answer 1

[Les Beckham]

You will need to use an array to store the four different df results. Since your df is going to be different sizes depending on the input argument N, I would recommend a cell array since normal arrays can't have different sized elements (e.g., rows).

Try this:

 N = [11 21 51 101];
 for (idx = 1:length(N))
     df{idx} = fowarddif(N(idx));
 end

This will store the four different results separately in the cell array df.

To extract the results for N=11, for example, you would use df{1}.

I hope this helps.