Polyfitting warning

hey guys,

when I am using the polyfit function i get the following error printing in the command window:

"Warning: Polynomial is badly conditioned. Add points with distinct X values, reduce the degree of the polynomial, or try centering and scaling as described in HELP POLYFIT. "

I was wondering if there is a way to suppress the printing of this warning in the command window. I know what I am trying to do is correct for this situation. but I just wish it would stop printing it.

[Matt Fig]

This is not an error, but a warning message. An error would prevent you from getting a return value...

[olski one]

yeah sorry thats what i meant

Answer 1

[Matt Fig]

I'll take you at your word that you know what you are doing.

ws = warning('off','all');  % Turn off warning
P = polyfit(x,y,N);
warning(ws)  % Turn it back on.

Answer 2

[John D'Errico]

If you are getting that error message, then you are probably computing garbage for the coefficients of the polynomial. Don't suppress the warning, even while that IS possible to do. (help warning)

Deal with the problem and the message goes away. It is usually either due to overfitting the data with too high order of a model, or with poor scaling of your data. If you start suppressing the warning, then you won't be told when you DO have a problem. Closing your eyes does not make a problem go away.

Answer 3

[Arturo Moncada-Torres]

Mmm, there is a cheap way:

try
   % The code with the polyfit function goes here
catch
end

However I really recommend you to check that what you are doing is correct.

Hope it helps ;-) .

[Matt Fig]

TRY-CATCH has no effect with Warnings...

[Arturo Moncada-Torres]

Oh really? I think then I have used it with error messages only. Anyway, it is good to know, thanks! =)