How to plot step functions in Matlab

222 views (last 30 days)
Sangani Prithvi
Sangani Prithvi on 31 Oct 2020
Commented: VBBV on 31 Oct 2020
I have a function involving
y=o for x<o;
y=exp(-x)*cos(x) for 0<x<2pi();
y=2*exp(-x)*cos(x) for x>2pi();
please help me to plot such a type of function in xy space

Accepted Answer

VBBV on 31 Oct 2020
Edited: VBBV on 31 Oct 2020
%if true
% code
x = -2*pi:0.1:3*pi;
for i = 1:length(x);
if x(i)<0;
elseif x(i)<=2*pi & x(i)>=0 ;
y(i) = exp(-x(i))*cos(x(i)*pi/180);
elseif x(i) > 2*pi ;
y(i) = 100*exp(-x(i))*cos(x(i)*pi/180);
axis([-2*pi 3*pi -0.2 1])
VBBV on 31 Oct 2020
you can use a smaller number, say 2, but
y(i) = 2*exp(-x(i))*cos(x(i)*pi/180);
gives a very small step height compared to
y(i) = exp(-x(i))*cos(x(i)*pi/180)
So in the graph it is not noticeable clearly
Thats why i used to 100 which amplifies the step height.
Remember in both cases the step nature does not vary. i,e, decreasing exponential function according to your equations

Sign in to comment.

More Answers (1)

Vladimir Sovkov
Vladimir Sovkov on 31 Oct 2020
Edited: Vladimir Sovkov on 31 Oct 2020
syms x;
y=piecewise(x<0,0, 0<=x<2*pi,exp(-x).*cos(x), x>=2*pi,2*exp(-x).*cos(x));
Vladimir Sovkov
Vladimir Sovkov on 31 Oct 2020
By the way, in the question, you did not specify what the function is equal to at the boundary points x=0 and x=2*pi; in the code I implied the right limit but you can easily alter this convention.

Sign in to comment.


Find more on Line Plots 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!