Error using ^, inputs must be scalar and square matrix

Question

0 个投票

SO I'm writing a Lagrange polynomial code and I've hit another error. I'm trying to evaluate a function at x over multiple points.

function f=larange2(func,n)
xi=linspace(-1,1,n);
yi=func(xi);
value=1;
zi=linspace(-1,1,100);
l=0;
ziy=[];
valuel=0;
for i=0:n
      for c=0:n
          if c~=i
              value=value*((zi(i)-xi(c))/(xi(i)-xi(c)));
          end
              if c==n 
                  ziy(i)=(value*yi(i));
              end
      end
  end
      for i=0:ziy.length()
      valuel=valuel+ziy(i);
  end
  f=valuel;
  end

I'm getting an issue when calling the function

   func=@(x) (1/(1+x^2));
values=larange2(func,3);
  end
Error using  ^ 
Inputs must be a scalar and a square matrix.
To compute elementwise POWER, use POWER (.^) instead.
Error in @(x)(1/(1+x^2))
Error in larange2 (line 4)
yi=func(xi);
Error in runl (line 3)
values=larange2(func,3);

SO what I'm asking, if I have an array of x values Xi (linspace gives me n evenly spaced points on an interval), and I want to calculate the y values into Yi for each x, what is the proper way to do it? A loop? My professor said that matlab would perform the function automatically as an array but it seems that there is a problem evaluating the function at x.