I am still battling with my project :( I have a line like this
lm(month.model$next.ret~.,month.model,na.action=na.omit) month.model is a data frame with lots of columns. One of them is "Oth", a dummy variable. I checked month.model, there are two rows with number 1 and others are either 0 or NA. the two rows with Oth==1 have no NA. I have totally about 900 rows. But after the regression, the Oth's coefficient is NA. I do not understand. Another issue is also about NA. I offen use something like "model[model$Oth==1,]", but it will not only gives rows with oth==1, but also gives some rows with all item as NA. I then changed this into " month.model[(month.model$Oth==1)&(!is.na(month.model$next.ret)),]" and it gives the same result. Finally I change it into " month.model[(month.model$Oth==1)&(!is.na(month.model$Oth)),]" and it works. next.ret is a column for sure. Can anyone explain this to me? ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
