Trapezoidal numerical integration - MATLAB trapz
www.mathworks.com › help › matlabQ = trapz (Y) computes the approximate integral of Y via the trapezoidal method with unit spacing. The size of Y determines the dimension to integrate along: If Y is a vector, then trapz (Y) is the approximate integral of Y. If Y is a matrix, then trapz (Y) integrates over each column and returns a row vector of integration values.