Write a function that produces a plot.

Write a function that takes arrays x and y as inputs and produces a plot of the Lagrange interpolating polynomial. The plot should also include markers for the data points in x and y. This function will need to ll in a divided di[ff]erences table and will need to evaluate the interpolating polynomial at enough points to produce a smooth plot. There is an outline for the code on Blackboard if you need help. You may want to test your algorithm on a table you have lled in by hand. Email this function le to your grader.

As an example, for the following data,

x=[0 3 4.5 6 9];
y=[0 .5 .7071 .8660 1];

This is what I have so far

x = [1 1.2 1.5 1.7 2.0];
y = [1 0.6944 0.4444 0.3460 0.2500];
n = length(x);
n2 = length(y);
F = ones(n2,n+1);
for i = 2:n
  for j = 2:i
      F(:,j) = F(:,j).*(x'-x(i))/(x(j)-x(i));
  end
end
disp(F)

[Steven Lord]

If you post what you've done to try to solve this problem and ask a specific question you may receive some suggestions about how to move forward.

[randal urso]

I have posted what i have so far.

[John BG]

Randal

Mr Castoldi already solve this, have a look here

https://uk.mathworks.com/matlabcentral/fileexchange/899-lagrange-polynomial-interpolation/content/lagrange.m

regards

John BG

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