You seemed to have re-written over the "b" object in your code. This might work for you.
library(MASS) for (i in 58:1){ for(j in 58:i){ str.temp <- paste("y1 ~ x", i, "* x", j, sep = "") univar <- glm.nb(as.formula(str.temp), data=df) b <- summary(univar)$coeffients[4, 4] if(b < 0.6){ cat(i, j, b, "\n") } } } By the way, you should post using plain text (not html). Jean On Thu, Aug 18, 2016 at 6:48 AM, fatimah soleimany < fatimah.soleim...@gmail.com> wrote: > Hi Dear users, > for an interactive use, i am trying to write a loop that looks for all > variables in the conditions which i introduced, this is what I'm trying: > > library(MASS)> i=1> for (i in 58:1){+ for(j in 58:i){+ + str.temp <- > paste("y1 ~ x", i, "* x", j, sep = "")+ > univar<-glm.nb(as.formula(str.temp), data=df)+ > b=summary(univar)$coeffients[4,4]+ b<-c(i,j)+ if(b < 0.6){ + > print(b)+ }+ }+ } > > i have no error but i didn't get true response too, my result is this: > > > b[1] 1 1 > > but i want all the variables that their p-value are less than 0.6, i > think i couldn't write a true loop,can you help me? > > thank you in advance for any help > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/ > posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.