## Matrix dimension does not agree when using .*

### Sena Ece Uzungil (view profile)

on 1 Apr 2019
Latest activity Answered by Kelly Kearney

on 1 Apr 2019

### Kelly Kearney (view profile)

Our code is calculating Taylor polynomials. We are sure that the problem is about P1 because program is plotting PO and f(x). We would really appreciate if anyone can solve our problem.
clc
clear all
close all
h = 0.01; % step size
X = -pi/8:h:7*pi/8; % domain
f=@(X) cot(X); % range
a=5*pi/8
Z1=@(X) diff(cot(X)) %first derivative
Z2=@(X) diff(cot(X),2) ; %second derivative
Z3=@(X) diff(cot(X),3) ; %third derivative
P0=@(X) f(a)*ones(size(X))
P1=@(X) f(a) + Z1(a).*(X-a);
P2=@(X) P1 + Z2(a) ./ factorial(2).*((X-a).^2);
P3=@(X) P2 + Z3(a) ./ factorial(3).*((X-a).^3);
xlim([0.1 3])
ylim([-2.5 2.5])
hold on
plot(X,f(X),'k','Linewidth',2)
plot(X,P0(X),'r','Linewidth',2)
plot(X,P1(X),'g-.','Linewidth',2)
plot(X,P2(X),'b--','Linewidth',2)
plot(X,P3(X),'m:','Linewidth',2)
Error using .*
Matrix dimensions must agree.
Error in Untitled>@(X)f(a)+Z1(a).*(X-a)
Error in Untitled (line 26)
plot(X,P1(X),'g-.','Linewidth',2)

on 1 Apr 2019