[R] Calculating the mean in one column with empty cells

[Berend Hasselman]

On 05-10-2012, at 11:27, fxen3k wrote:

> Hi all,
> 
> I recently tried to calculate the mean and the median just for one column.
> In this column I have numbers with some empty cells due to missing data. 
> So how can I calculate the mean just for the filled cells? 
> I tried:
> mean(dataSet2$ac_60d_4d_after_ann[!is.na(master$ac_60d_4d_after_ann)],
> na.rm=TRUE)
> But the output was different to the calculation I died in Microsoft Excel.
> 

No data ==> no can answer question.

What did you expect?
What did Excel give you?

But you are trying to calculate the mean of  dataSet2$ac_60d_4d_after_ann and indexing with the indices of  non-NA numbers of  master$ac_60d_4d_after_ann.

mean(dataSet2$ac_60d_4d_after_ann, na.rm=TRUE) 

should do what you want.

Berend