nansum for double or single -> why error?

hi :)

can please someone explain to me how I can use nansum for a vector? I always get this error:

Undefined function 'nansum' for input arguments of type 'single'.

same for double >> in what datatype do I have to transform the data?

Thx for ur help.

Answer 1

[Cedric]

Are you using a version of MATLAB anterior to 2006a? Evaluate ver or version to check. Or maybe you shadowed the function by naming a variable nansum by mistake during your tests. To check, evaluate

 which nansum

and see if you get something like

 C:\Program Files\MATLAB\R2015b\toolbox\stats\stats\nansum.m

[Marco Bergamin]

... thx didn't know that this function requires a toolbox licence :S

C:\Program Files\MATLAB\R2015a\toolbox\stats\stats\nansum.m  % Has no license available

[Cedric]

Ok, we can help you implement something similar "by hand" if you need (?)

[Cedric]

Well, here is one way to do it:

 function s = nansum( A, varargin )
    A(isnan( A )) = 0 ;
    s = sum( A, varargin{:} ) ;
 end

Answer 2

[Steven Lord]

Marco, since you're using release R2015a (according to your comment on Cedric's answer) you can use SUM with the appropriate nanflag input argument instead of NANSUM.

 x = [1:10 NaN];
 sum(x, 'omitnan')

[Cedric]

I had never realized that this flag was implemented, thank you for the update!

[Steven Lord]

Not only does SUM accept this flag, but so do a number of the other basic statistical calculation functions. For a full list, see the second item in the Mathematics section of the release R2015a Release Notes for MATLAB.

[Cedric]

Thank you Steven! I obviously don't spend enough time reading release notes.