Conv error / frequency domain error

Hello,

A friend of mine provided me with some code to help me learn control design. However, he wrote it in a previous version of Matlab and now the following code is giving me errors. I have used the "tf" command many times and I am not sure why it isn't working now...

Tdel = 1/5; wdel = 2*pi/Tdel; s = tf('s'); Cds = wdel*eye(4)/(s+wdel);

Which gives me this error message:

Error using + (line 63) Undefined function 'conv' for input arguments of type 'double'.

Error in Investigation (line 4) Cds = wdel*eye(4)/(s+wdel);

Any insight would be appreciated!

Answer 1

[Image Analyst]

I don't see the call to conv() in your code. But anyway, maybe you're passing in a uint8 array or something. Just cast the arrays to double like it asked you to and it should work.

[Image Analyst]

Bryce's "Answer" moved here:

That's the thing, I don't call a conv(). I've run this exact code in 2012 & 2013 with no issue. You can get rid of everything but the following:

s = tf('s'); Cds = s+5;

and you get the same error "Undefined function 'conv' for input arguments of type 'double'."

It's like it is choking on the numerical and Laplace summation.

[Image Analyst]

Set a breakpoint on line 63 and see what the values are. Do you know how to use the debugger? http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/