I'm using count data in quite a simple way, but I cannot understand how a binomial glm can return negative predictions
example code, where count of successes increases with responce variable:
suc=c(1:10)
fail=c(10:1)
predict(glm(cbind(suc,fail)~c(1:10),family=binomial))
which results in:
-1.9974174 -1.5535469 -1.1096763 -0.6658058 -0.2219353 0.2219353 0.6658058 1.1096763 1.5535469 1.9974174
I don't understand this: how can a binomial model give these predictions? It should be integer positive predictions, no?
Best Answer
Assuming that you are using the
predict.glm()
from thestats
package.A quote from the manual, under the entry explaining the type parameter:
So instead, try the following: