Orange Forum • View topic - Threshold for Variance of z is zero ... warning

## Threshold for Variance of z is zero ... warning

A place to ask questions about methods in Orange and how they are used and other general support.

### Threshold for Variance of z is zero ... warning

What is the threshold value of variance that triggers the ValueError: "Variance of y is zero (or near zero).

I would like to do a quick check for this error as a validation before starting more complicated calcuations.

Thanks--Steve

### Re: Threshold for Variance of z is zero ... warning

Just a follow up -- Is this definition of variance based on n or n -1?

Thanks--Steve

### Re: Threshold for Variance of z is zero ... warning

This is probably raised here http://orange.biolab.si/trac/browser/orange/Orange/regression/earth.py#L678 so the threshold would be 1e-8.
sreastman wrote:Is this definition of variance based on n or n -1?
On 'n'

### Re: Threshold for Variance of z is zero ... warning

Ales

Great. Just what I needed to know.

Steve