Mean value of a column

[rolivella]

Hi all,

This should be a simple calculation but I don’t know how to do it. My dataset is like this:

And I simply want to calculate the mean of the “values” column. I’ve tried the “Group by” and “Statistics” modules but:

1. Group by: I put the “Groups” tag with “values” and “Type Based Aggregation” with “Number (long)” and “Mean”. But I get: “No aggregation column defined”. But I I define am aggreation column I don’t know how to select all the “values” data…

2. Statistics: I simply select “values” in “Options” tab nut when I run it I get the output statistics table empty.

Any idea? Thank you!

Roger Olivella

[stelfrich]

Dear @rolivella,

it seems like the data type of your values column is String. There is a String to Number node that you can use to convert those entries to “proper” numbers. Subsequently, you can use the GroupBy node with a Manual Aggregation, add the values column, and select the default aggregation method (dropdown in the Aggregation column) Mean (should be the default anyway).

Best,
Stefan

[rolivella]

Thank you, that perfectly worked!

Roger