Hi all, I created a predicted variable based on a model, but somehow not all observations have a predicted value. When I tired to add the predicated value to the main data set (data$pr <- pr) , it said: replacement has 34333 rows, data has 34347. Do you know how to solve that? Thanks, Manqing
replacement has *** rows, data has ***
3 messages · Manqing Liu, William Dunlap, David Winsemius
This can happen if there are rows containing missing values (NA's) in the data used to fit the model. Use na.action=na.exclude when fitting the model instead of the default na.action=na.omit to make the prediction vector line up with the input data instead of lining up with the input data after the NA-rows have been dropped. E.g.,
d <- data.frame(y=1:10, x=log2(c(1,2,NA,4:10))) fitDefault <- lm(y ~ x, data=d) fitNaExclude <- lm(y ~ x, data=d, na.action=na.exclude) length(predict(fitDefault))
[1] 9
length(predict(fitNaExclude))
[1] 10
predict(fitNaExclude)
1 2 3 4 5 6 7 8 9 10 -0.2041631 2.4602537 NA 5.1246704 5.9824210 6.6832543 7.2758004 7.7890872 8.2418382 8.6468378 Bill Dunlap TIBCO Software wdunlap tibco.com
On Mon, Jun 12, 2017 at 1:32 PM, Manqing Liu <hopkins0727 at gmail.com> wrote:
Hi all,
I created a predicted variable based on a model, but somehow not all
observations have a predicted value. When I tired to add the predicated
value to the main data set (data$pr <- pr) , it said:
replacement has 34333 rows, data has 34347.
Do you know how to solve that?
Thanks,
Manqing
[[alternative HTML version deleted]]
______________________________________________ R-help at 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.
On Jun 12, 2017, at 1:32 PM, Manqing Liu <hopkins0727 at gmail.com> wrote: Hi all, I created a predicted variable based on a model, but somehow not all observations have a predicted value. When I tired to add the predicated value to the main data set (data$pr <- pr) , it said: replacement has 34333 rows, data has 34347. Do you know how to solve that? Thanks, Manqing [[alternative HTML version deleted]]
First, you should read the Posting Guide. Then you should read the help page for ?predict. Only then should you write a follow-up email (in plain text) with code that constructs a simple example using whatever method was used to construct this `pr` variable and provide enough information to support a sensible answer.
______________________________________________ R-help at 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.
David Winsemius Alameda, CA, USA