lagranges method - matlab

Question

I found following code on internet. I am new to matlab. Now the problem whenever i copy-paste this code then it shows me error message.
function[p] = lagrange_interpolation(X,Y)
|
Error: Function definitions are not permitted in this context.
The code snippet is:
function[p] = lagrange_interpolation(X,Y)
L = zeros(n);
p = zeros(1,n);
% computing L matrice, so that each row i holds the polynom L_i
% Now we compute li(x) for i=0....n ,and we build the polynomial
for k=1:n
multiplier = 1;
outputConv = ones(1,1);
for index = 1:n
if(index ~= k && X(index) ~= X(k))
outputConv = conv(outputConv,[1,-X(index)]);
multiplier = multiplier * ((X(k) - X(index))^-1);
end
end
polynimialSize = length(outputConv);
for index = 1:polynimialSize
L(k,n - index + 1) = outputConv(polynimialSize - index + 1);
end
L(k,:) = multiplier .* L(k,:);
end
% continues
end

Answer 1

In all likelihood, you are probably attempting to mix random code along with your function. There are two types of M files:
scripts - have "random" code that is executed independent of anything else
functions - are the "classic" definition of functions
You cannot mix the two (that's a lie, but for now a good one). So if you are defining a function, that should be the only code in your .m file.
You should later use this function in either the command window or another function or a script by calling it via p = blahblah(bleaurgh);.
TL;DR: Make sure the function code is the only code in the script file, save it with the same name.m, call the function from somewhere else.