Documentation

This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

nanmean

Mean ignoring NaN values

Syntax

y = nanmean(X)
y = nanmean(X,dim)

Description

y = nanmean(X) is the mean of X, computed after removing NaN values.

For vectors x, nanmean(x) is the mean of the remaining elements, once NaN values are removed. For matrices X, nanmean(X) is a row vector of column means, once NaN values are removed. For multidimensional arrays X, nanmean operates along the first nonsingleton dimension.

y = nanmean(X,dim) takes the mean along dimension dim of X.

    Note:   If X contains a vector of all NaN values along some dimension, the vector is empty once the NaN values are removed, so the sum of the remaining elements is 0. Since the mean involves division by 0, its value is NaN. The output NaN is not a mean of NaN values.

Examples

Find column means for data with missing values:

X = magic(3);
X([1 6:9]) = repmat(NaN,1,5)
X =
   NaN     1   NaN
     3     5   NaN
     4   NaN   NaN
y = nanmean(X)
y =
   3.5000  3.0000  NaN

See Also

| |

Introduced before R2006a

Was this topic helpful?