predicting glm on a new dataset
Christian Jones wrote:
Hello together, I would like to predict my fitted values on a new dataset. The original dataset consists of the variable a and b (data.frame(a,b)). The dataset for prediction consists of the same variables, but variable b has a constant value (x) added towards it (data.frame (a,b+x). The prediction command returns the identical set of predicted values as for the original dataset yet I would have expected them to change due to b+x. Were have I gone wrong? Heres my code: orig.frame<-data.frame(y,a,b) pred.frame<-data.frame(a,b+x) attach(orig.frame) modela<-glm(y~a+b,binomial) pr<-predict(modela,newdata=pred.frame,type="response")
Does this work for you? orig.frame <- data.frame(y, a, b) pred.frame <- data.frame(a, b = b + x) modela <- glm(y ~ a + b, family = binomial, data = orig.frame) pr <- predict(modela, newdata = pred.frame, type = "response")
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