Undefined function 'triang' for input arguments of type 'double'.

Hi there,

I get the same problem as the user here: https://www.mathworks.com/matlabcentral/newsreader/view_thread/295970

The suggested solutions do not work for me. Could you please let me know about the other potential solution?

Thanks!

[Stephen23]

What "solutions" are you referring to? That thread contains no "solutions" for a missing function, they are instructions telling you how to check if you have the Signal Processing Toolbox installed.

The advice was to run the command ver, which will print a list of the installed toolboxes. Have you done this? Please tell us exactly what the ver command prints.

Probably you do not have the Signal Processing Toolbox.

[Oliver Gloede]

Hi,

I was referring to the suggested checks in the previous threat:

"Do you have the Signal Processing Toolbox?"

-> Yes, I do.

"If you do have the toolbox then we need to check that your path is set correctly."

-> Yes, the path is correctly set.

"If all of the above checks out and it still doesn't work then I have another ace up my sleeve but it's a little more complicated. Let me know how you get on."

-> I would be grateful to receive further support how to solve the issue.

Thanks.

Answer 1

[Star Strider]

Looking at the algorithm for triang, an equivalent function is relatively easy to code.

These will work for even and odd values of window length ‘L’:

Leven = @(L) [(rem(L,2) == 0).*[(2*((1:(L/2))-1))/L, 2-((2*(((L/2+1):(L+1))-1))/L)]];
Lodd  = @(L) [(rem(L,2) == 1).*[(2*(1:(L+1)/2)/(L+1)),  (2-(2*(((L+1)/2+1):L)/(L+1)))]];

They emulate the published algorithm for triang as stated in Definitions. They also contain their own logic to be sure they only return a triangular window for the correct value of ‘L’. These are the essence of the function, so it would be straightforward to wrap them in your own version of triang and use it as an equivalent function file.

[Star Strider]

Since you have the Signal Processing Toolbox, you may have to reset a couple things.

The these in the Command Window (or in your script) and see if it corrects the problem:

restoredefaultpath 
rehash toolboxcache

[Oliver Gloede]

Thank you, resetting worked. Weird why that got messed up.

[Star Strider]

My pleasure.

If my Answer solved your problem, please Accept it.