How do I get eval( deriv(~F,"x") ) to return ONLY the values of the derivative of F? the default returns values of F(x), AND F'(x) as a ".gradient" attribute, and , after reading everything I have on eval(), deriv(), and attr(), I had absolutely no idea how to get just F'(x) evaluated a x. Many thanks, Henry Dr. M. Henry H. Stevens Postdoctoral Associate Department of Ecology, Evolution, & Natural Resources 14 College Farm Road Cook College, Rutgers University New Brunswick, NJ 08901-8551 email: hstevens at rci.rutgers.edu phone: 732-932-9631 fax: 732-932-8746 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._