This question is similar to the one you posted earlier from this book, but this time, instead of giving a function handle as input, we are only giving vectors x and y. The interquad function does not know the input function and just need to rely on these data points to find the integral. To guess the value at a point, not in vector x, we use interpolation. Try the following code to
x = 0:0.01:1;
y = x.^2;
a = interquad(x, y);
function Q = interquad(x, y)
f = @(xq) interp1(x, y, xq, 'pchip');
Q = quad(f, x(1), x(end));
end
It creates vectors x, and y from function
on the interval
. The output is as follow It is same as integral of
on interval 0 to 1.