multiple column meanSee attached, I tried to add a new column for mean from 3 other columns by "col mean( col1, col2, col3)". But the mean seems a little bit off, and I used "(col1+col2+col3)/3" to verify, and it gives me the correct result. What is the possible cause of this? 
Data Exploration and VisualizationRe: multiple column meanYou don't want the Col Mean() function, you just want the Mean() function
Re: multiple column meanExpanding on @txnelson's suggestion, the Col Mean() function uses the additional arguments after the first to group the data. This behavior is very convenient, but, as he said, not what you want this time.
