Stephan Rudolfer wrote:
I am working on a database of about 3,000 patients, and wish
to plot the ROC curves of various diagnostic algorithms
based on logistic regression, using roctab and roccomp.
Perhaps unsurprisingly, the plots are very "fuzzy",
presumably since the cutpoints generated depend on the total
number of patients in the database and hence are too numerous?
My question: Is it possible to get a "cleaner" ROC curve plot?
The roc routines don't seem to allow any control of the number
of cutpoints used for the ROCC.
========================================================
Steve pointed to some solution. Another possibility is -rocfit-
followed by -rocplot-. In the -rocplot- command I also included
some options that in my opinion improve the graph.
----------------------------------------
rocfit refvar classvar, continuous(10)
rocplot , ///
plotopts(msymbol(i)) ///
lineopts(lpattern(l)) ///
aspectratio(1) ///
plotregion(margin(zero)) ///
ylabel(, nogrid) xlabel(, nogrid)
----------------------------------------
Hope this helps
Svend
________________________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(School of Public Health, Department of Epidemiology)
Bartholins Allé 2
DK-8000 Aarhus C, Denmark
Phone: +45 8693 7796
Mobile: +45 2634 7796
E-mail: [email protected]
_________________________________________________________
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