请问 做逻辑回归的列线图，提示下标出界，这该如何解决？急急急
mydata$bmi.group<-factor(mydata$bmi.group,levels=c(1,2),labels=c("<18.5kg/m2","≥18.5kg/m2"))
> mydata$ASA<-factor(mydata$ASA,levels=c(1,2,3),labels=c("I","II","III"))
> mydata$CCI<-factor(mydata$CCI,levels=c(1,2,3,4,5,6,7,8),labels=c("1","2","3","4","5","6","7","≥8"))
> mydata$harris.group<-factor(mydata$harris.group,levels=c(1,2,3,4),labels=c("Poor","Fair","Good","Excellent"))
> ddist <- datadist(mydata)
> options(datadist="ddist")
> mod <- lrm(group~ bmi.group + ASA + CCI + harris.group, data = mydata,x=T,y=T)
Warning message:
In lrm(group ~ bmi.group + ASA + CCI + harris.group, data = mydata,  :
  Unable to fit model using “lrm.fit”
> mod <- glm(group~ bmi.group + ASA + CCI + harris.group, data = mydata,x=T,y=T)
> nom<-nomogram(mod,lp=F,fun=function(x)1/(1+exp(-x)),funlabel="risk of second fracture",fun.at=c(0.05,seq(0.1,0.9,by=0.1),0.95))
Error in lims[[i]] : 下标出界
此外: Warning message:
In structure(limits, class = "data.frame", row.names = c("Low:effect",  :
  Calling 'structure(NULL, *)' is deprecated, as NULL cannot have attributes.
  Consider 'structure(list(), *)' instead.