I have an attached data.frame with a binary composite variable (comp) and a predictor (egfr). I am trying to plot a restricted cubic spline using: require (Hmisc) require (Design) rcspline.plot(x=egfr,y=comp,model="logistic",nk=5,knots=NULL, xlab="label1", ylab="Label2", plim=c(0,1), plotcl=TRUE, showknots=TRUE, add=FALSE, lty=1, noprint=FALSE, smooth=FALSE, main="Title goes here "); I get the following error message (exactly as cut/pated): Loading required package: package Error in requirePackage("Design") : This function requires theDesignpackage In addition: Warning message: there is no package called 'package' in: library(package, lib.loc = lib.loc, character.only = TRUE, logical = TRUE, Should I be using an additional package? Any suggestions will be appreciated. Thanks, Gerard Smits [[alternative HTML version deleted]]