How can I return a set of values in an array from a function file?

I have a function file that I wrote and I want it to return 2 arrays of values not just a single value. My function file looks like this

function [yf,relError,count] = myroot(a,yb,error,countmax)

count=0;
while 1 
ybold = yb;
yb= 0.5*(yb + a/yb);
count = count +1;

if yb ~= 0
  relError = abs((yb-ybold)/yb);
end
if relError <= error || count >= countmax
break
end 
end

yf=yb;

How can I create a vector or array that returns all calculated values of yf and relError? I think it would require me to initialize a vector made of zeros to begin with but Im not sure. Any help would be appreciated. Thank you.

Answer 1

[Simon]

Hi!

First you may create an empty array like

yf = zeros(countmax, 1);

This gives you an array of maximum size. In your loop you set

yb= 0.5*(yb + a/yb);
count = count +1;
% now save in array
yf(count) = yb;

The same you do with your error.

You do not fill your vector up to the last entry with vales, depending on the error. So it is usefull to crop the vectors before returning from the function to get rid of the extra zeros, like

yf = yf(1:count);

And the same for the error.