Need help with this Matlab code. Thank you.

1) write a generic function to integrate | (x)dr with the following format function 1 integrator ( x, y, method) = where x is a vector and y is a matrix whose columns y (: ,j) are vectors of the same length as x and contain equally spaced data points. The output I is a row vector whose elements are the integrals of each column of y with respect to x. In other words, the jth element of I is I()- [y(.j)dr method is the technique used, and should either be the string trap' for the trapezoidal rule or 'simp' for Simpson's 1/3 rule. If the method argument is missing in the integrator function call, the default method should be set to the trapezoidal. The integrator function should evaluate the number of intervals to integrate and should check that this number is even when Simpson's 1/3 rule is selected; if that's not the case, the function should stop and print an error message warning the user The integrator function should contain 2 subfunctions (local functions), one to implement the trapezoidal rule and one to implement Simpson's 1/3 rule. No loop should be used (use vector operations only). Check your subfunctions with simple problems for which you know the answer. Hint: You may want to start writing this function for the easier special case of integrating a vector y and obtaining a scalar output I, and then, after checking your results, modifying your code to handle the general case of a matrix y yielding a vector