standard deviation over columns

[Egbert Vierkant]

Hi

I am struggling with a seemingly simple problem, but I can't solve it...

I want to calculate the standard deviation of five columns as a new variable. Just like I can calculate the average of these columns. The stdev function only takes a vertical look, not the horizontal...

What should I do

Any suggestions

 

Thanks & Kind regards

Egbert

[Gaia Paolini]

Hi

 

Since the Avg function does accept multiple arguments, you could use the formula for the standard deviation directly, which simplifies as

SQRT( N/(N-1) * ( Avg(x^2)-Avg(x)^2 )

In your case x is the vector of the 5 columns, and N=5.

 

This would be:

Sqrt(5 / 4 * (

avg([col1] * [col1],[col2] * [col2],[col3] * [col3],[col4] * [col4],[col5] * [col5]) - (

avg([col1],[col2],[col3],[col4],[col5]) ^ 2)))

Gaia