MATLAB: Trying to plot x,y, but it says error in y = f(x);

plot

 function graph
 x = 1:100;
 y = f(x);
 plot(x,y);
 end
 function [y] = f(n)
 y = n * log2(n);
 end

You need to use element-wise operations in this line:

   y = n .* log2(n);

Note the ‘.*’ replacing the ‘*’. See the documentation for Array vs. Matrix Operations for details.

>> X = linspace(-8,8,500);
>> Y = fresnelS(@(x) sin(x.^2), X, 50);
>> plot(X,Y)

unction definitions of that sort are not permitted in regular script files, only within other function files. You have to create a new script with:

function y = f(x)

as the first line, then save the file as f.m. It should work then.

To call it from your main script:

x = 10;      % Random choice
y = f(x)