NaN Suite

Descriptive Statistics for N-D matrices ignoring NaNs.

Description

The collection of functions in the NaN Suite enhances the functionality of the original 'nan'-functions in the Statistics Toolbox for N-D matrices. In addition, the new function nansem.m calculates the standard error of the mean ignoring NaNs.

The NaN Suite functions are used similar to the original functions (e.g. mean, std, var), that is they take a matrix as the first input, and the dimension along which the operation should be computed as the second input. For example, nanmean(A,4) calculates the mean of A along the 4th dimension of A ignoring NaNs.

• Acknowledgements: This submission has inspired the following:; Cpk capability index with NaN's, PIVlab - time-resolved particle image velocimetry (PIV) tool
• MATLAB release: MATLAB 6.5 (R13)

[Julie Golomb]

so useful -- thank you!

[Can Ozan Tan]

pretty handy

[Daphne Weihs]

Thanks!
This happened to be just what I needed.

[Rudolf von Steiger]

 

[dgfgf ddf]

thanks a lot

[Uri Merhav]

Great minds think alike, I see. I was just about to write out this code myself when I realized someone out there must also be using nan as a non-measurement, and want it ignored while computing average and standard deviation.

Good job.

[Santosh Verma]

nice

[anony mouse]

genius!

[Pieter Kuppens]

Isn't life as simple as this:
nanmean(a) = mean(a(find(~isnan(a))))

[David Redish]

Thank you for fixing this. We have been bitten regularly by Mathworks' strange decision to define nanxyz(all-nans) as 0, which propogates nans incorrectly. This suite has helped us tremendously.

[C D]

This is a great suite of functions. I did notice the max/min toolbox functions in M7 filtered NaN's from the calculations. However, the other functions did not. So, that's where the NaN suite came in handy.

[miguel Ampudia]

is there any function to do quintiles ignoring NaN? Thanks!

[Andrei Terebilo]

Little bug here (otherwise great, thanks):

>> nanmedian([0 0 0 0 0 1])
ans =
   NaN

Just modify line 71:
i = find(y==0);
to
i = find(s==0);

[WP]

Thank you so much, this is useful!

[Thul Dai]

Great package, thanks!

Also agreeing on the bug as well as fix found by Andrei Terebilo on 09 Oct 2009. Would be nice if the downloadable package could be fixed.

[Thomas Clark]

Brilliant, thanks.

I'd give five stars if Andrei's bugfix were included. Will upgrade to 5* if the bug is fixed :)

[Binu]

There is a bug in the order by which the Nan suite calls the 'dim' argument. This matters if you have replaced the matlab 'NaN' functions with the Nan suite.

NaNsuite y = nanstd(x,dim,flag)
MATLAB y = nanstd(X,flag,dim)
         y = std(X,flag,dim)

[W Thielicke]

Thanks for the contribution!

[Philip West]

The issue Binu found is also present in the nanvar function. where:

NaNsuite y = nanvar(x,dim,flag)
MATLAB y = nanvar(X,flag,dim)

[David]

Just what I was looking for :-)
Haven't looked at why, but seems to run a little slowly.
Thanks :-)