st: Hosmer-Lemeshow statistic

["Mitchell F. Berman" <mfb1@columbia.edu>]

Stata list users:

I need to manually run a Hosmer-Lemeshow goodness of fit statistic.

Using the lbw data (reference manual: logistic section)

running the logistic as it appears in the manual, followed by the estat 
gof gives the correct HL statistic and a table.

xi: logistic low age lwt i.race smoke ptl ht ui
estat gof, group(10) table

How is Stata getting from the table with observed and expected values to 
a chi2 of G-2 =8 degrees of freedom?  What form of chi2 are they using.  
Can anyone reproduce the HL statistic from the table with a call to a 
form of chi2 available in Stata?

I need to reproduce and modify this step.

Thanks in advance.

Mitchell Berman
Columbia University
New York, NY
*
*   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/