bigglm binomial negative fitted value
On Fri, Jun 1, 2012 at 1:17 AM, Yue Guan <pipehappy at gmail.com> wrote:
Hi, there Since glm cannot handle factors very well. I try to use bigglm like this: logit_model <- bigglm(responser~var1+var2+var3, data, chunksize=1000, family=binomial(), weights=~trial, sandwich=FALSE) fitted <- predict(logit_model, data) only var2 is factor, var1 and var3 are numeric. I expect fitted should be a vector of value falls in (0,1) However, I get something like this: str(fitted) ?num [1:260617, 1] -0.0564 -0.0564 -0.1817 -0.1842 -0.1852 ... ?- attr(*, "dimnames")=List of 2 ?..$ : chr [1:260617] "1" "2" "3" "4" ... ?..$ : NULL
As the help says, the default is predictions of the linear predictor. To get predictions of the probability, use type="response" -thomas
Thomas Lumley Professor of Biostatistics University of Auckland