Hi Dear
In my PhD project, I was having problem to have a good model with 
Thikonov Regularization in inverse problem. I checked the data and 
try to get a good distribution of the data set.  I did log transform 
of raw data and run the model with transformed data. The model that I 
get is fantastic. Now I am happy to put the model, however, I think I 
have to justify the data transformation. So how can I justify?
Cheers
Bilal
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/