I want to create the following function bu i get an error

a = randi([2,5]);
Ts = 1/20/a;
dur = 10;
t = -dur/2:Ts:dur/2-Ts;
g = zeros(1,length(t));
g(t>=0 & t<1) = 5*t-2;
g(t<2 & t>=1) = 3;
g(t<4 & t>=2) = -2*t+1;

gives the error Unable to perform assignment because the left and right sides have a different number of elements.What should i do?

Answer 1

[Walter Roberson]

a = randi([2,5]);
Ts = 1/20/a;
dur = 10;
t = -dur/2:Ts:dur/2-Ts;
g = zeros(1,length(t));
mask = t>=0 & t<1;
g(mask) = 5*t(mask)-2;
mask = t<2 & t>=1;
g(mask) = 3;
mask = t<4 & t>=2;
g(mask) = -2*t(mask)+1;

g

g = 1×1000

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Answer 2

[Jogesh Kumar Mukala]

Hi,

Assuming you are trying to create a piecewise function g(t), I understand that the problem is with the last three lines of the code you have attached. You can better use symbolic variables to create your piecewise function. Please find the reference to use symbolic variables and create piecewise function.

There are a few examples attached on the doc page that might meet your problem requirements.

[Walter Roberson]

piecewise applies only to symbolic inputs, and since T is numeric you would need to either create a symbolic function or else subs() the numeric value into a symbolic expression.