How can I include membership function inside a piece-wise function?

I'm trying to graph a piecewise function containing sigmoid membership function, however the result is always returned with dimension mismatch error. Any idea? Thanks.

Here's the code:

x= 0:.1:20;

y(0<=x & x<=10) = sigmf(x,[1 5]);

y(10<x & x<=20) = 1;

plot(x,y)

Answer 1

[Robert U]

Hi Kris,

since you are using logical indexing, you must account for different sized vectors you want to write on (in your example the length of y is not the same as x). One possibility is to initialize the vector y by one and overwrite the values y(0<=x & x<=10):

 x= 0:.1:20;

 y = ones(1,length(x));
 y(0<=x & x<=10) = sigmf(x(0<=x & x<=10), [1 5]);

 plot(x,y)

Kind regards,

Robert