Creating crea.select

#To create crea.select, a subset of crea.rep used for feature selection:

load("crea.repvx.rda")

crea.select<-crea.rep[!crea.rep$EstPregnant==1&!crea.rep$RRT==1&!crea.rep$Transplant==1&crea.rep$Prehf==0,] 

#Exclude maternity tests, data from RRT, transplant and pre heart failure patients.

crea.select<-crea.select[,c(x:y,z....)] 

#Use column positions to omit all columns referencing future metrics (*_6M,Dead,Max*) 
#Also remove unecessary columns now redundant (EstPregnant, RRT, RRTDate,Transplant,EntryDate if event.date is retained)

summary(crea.select)
#Note which columns should enter clustering as factors not as continuous variables. This includes categorical drugs columns. 
#Reclassify as a group based on position:

for(i in c(x,y:ncol(crea.select))) {
    crea.select[,i] <- as.factor(crea.rep[,i]) #Replace x and y with the numeric range of the columns being altered
    
    save(crea.select,file="crea.select.rda")