Why do I get Matrix dimensions must agree? I am trying to plot the frequency response of this function.

2 views (last 30 days)
clear all; close all; clc;
%Problem 1:
w = linspace(-pi, pi,2001);
X = (1/(1-exp(-j.*w)))*(sin(1.5.*(w))./sin(w./2))+5*pi*dirac(w);
%Frequency Domain Plot
plot(w, X);
Error using /
Matrix dimensions must agree. (line 4).

Accepted Answer

Clayton Gotberg
Clayton Gotberg on 26 Apr 2021
Edited: Clayton Gotberg on 26 Apr 2021
X = (1/(1-exp(-j.*w)))*(sin(1.5.*(w))./sin(w./2))+5*pi*dirac(w);
% ^
% This is your problem!
When MATLAB sees a scalar being divided by a matrix, it doesn't make the assumption that you want to perform the operation element-wise, like it does when you multiply a scalar and matrix or when you divide a matrix by a scalar.
x = [4 2];
y = 1/x; % Error because 1/[4 2] isn't interpretable as a matrix operation.
y = 1./x; % Returns [0.25 0.5]

More Answers (0)


Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by