How to transform right skewed data with heavy concentration at zero value?

[anu1999]

Hi,

I am working with a data with 50+ variables as input to the model. Most of the input variables have the right skewed distribution heavy at 0 value. I know log transformation is used for right skewed data but in my case when I have high concentration of zero, it wont help.

I was wondering if you have any suggestions based on your past experience on how you dealt with such data for modeling.

Thanks
A

[Ksharp]

Did your data confirm Possion distribution ? 

You could check Zero Inflation Model.

[anu1999]

Hi Xia,

Thanks for suggestion. After reasearching, it looks like  Zero Inflation model is the right choice here. Do you know if this can be implemented in SAS enterprise miner. 

Thanks.

[WendyCzika]

You can fit a GLM with the zero-inflated Poisson distribution in the HP GLM node in Enterprise Miner (in releases 13.1 and beyond). But that's for a target that has many 0's.  For inputs that are skewed, you could still use a Log transformation, just need to add a constant to the variables first to be able to log 0.  The Transform Variables node in EM can do the log transformation and will automatically add a constant.