Hello, I am running a step.gam with 21 explanatory variables. I run into a problem with the "Error: cannot allocate vector of size 437.9 Mb" if the list of explanatory variables is longer than 17. I have to comment out 4 of the variables and can't test than 17 variables (see below). I am wondering if there is a work around this problem. Please help, Mahesh gam.object <- gam(YVAR~1, data=gam.data) step.object <-step.gam(gam.object, scope=list( "FAC1"=~1+FAC1, "FAC2"=~1+FAC2, "FAC3"=~1+FAC3, "NUM1"=~1+NUM1+ns(NUM1,df=2), "NUM2"=~1+NUM2+ns(NUM2,df=2), "NUM3"=~1+NUM3+ns(NUM3,df=2), "NUM4"=~1+NUM4+ns(NUM4,df=2), "NUM5"=~1+NUM5+ns(NUM5,df=2), "NUM6"=~1+NUM6+ns(NUM6,df=2), "NUM7"=~1+NUM7+ns(NUM7,df=2), "NUM8"=~1+NUM8+ns(NUM8,df=2), "NUM9"=~1+NUM9+ns(NUM9,df=2), "NUM10"=~1+NUM10+ns(NUM10,df=2), "NUM11"=~1+NUM11+ns(NUM11,df=2), "NUM12"=~1+NUM12+ns(NUM12,df=2), "NUM13"=~1+NUM13+ns(NUM13,df=2), "NUM14"=~1+NUM14+ns(NUM14,df=2) #"NUM15"=~1+NUM15+ns(NUM15,df=2), #"NUM16"=~1+NUM16+ns(NUM16,df=2), #"NUM17"=~1+NUM17+ns(NUM17,df=2), #"NUM18"=~1+NUM18+ns(NUM18,df=2) )) [[alternative HTML version deleted]]