AMATH 301 Lecture Notes - Lecture 17: Matlab
Document Summary
% fminsearch (@f,) or ("f",) both will reference the function file f, Last time cont, numerical derivatives clear all; close all; clc x = 0:0. 1:6; y = x. *cos(x); plot(x,y,"k", x,y,"ro") hold on yprime = cos(x) -x. *sin(x); plot(x, yprime, "k") x0 = x(30); y0 = y(30); yprime0 = yprime(30); hold on plot(x0, yprime0, "r. ", "markersize", 20) yprime_b = (y0 - y_1) / dx; plot(x0, yprime_b, "g. ", "markersize", 20) yprime_c = (y1 - y_1) / (2*dx); 2nd order y_prime_2nd = zeros(n,1); y_prime_2nd(1) = (-3*y(1) + 4*y(2) - y(3)) / (2*dx); for k = 2:n-1 y_prime_2nd(k) = (y(k+1) - y(k-1)) / (2*dx); 3 end y_prime_2nd(n) = (3*y(n) - 4*y(n-1) + y(n-2)) / (2*dx); close all plot(x, yprime, "k", x, y_prime_2nd, "r") % ydprime(1) = (-3*y_prime_2nd(1) + 4*y_prime_2nd(2) - y_prime_2nd(3)) / (2*dx); % ydprime(k) = (y_prime_2nd)(k+1) - y_prime(2nd)(k-1)) / (2*dx);
