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nansum

Sum ignoring `NaN` values

Syntax

`y = nansum(X)y = nansum(X,dim)`

Description

`y = nansum(X)` is the `sum` of `X`, computed after removing `NaN` values.

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

`y = nansum(X,dim)` takes the sum 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`. The output `0` is not a sum of `NaN` values.

Examples

Find column sums 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 = nansum(X) y = 7 6 0```