generalized linear models

  1. K

    How family=Poisson works in glm function in R?

    Let's assume I am working with this dataset on R: n <- 40 x1 <- rnorm(n, mean=3, sd=1) x2 <- rnorm(n, mean=4, sd=1.25) y <- 2*x1 + 3*x2 + rnorm(n, mean=2, sd=1) mydata <- data.frame(x1, x2, y) I cannot understand how Poisson regression works in R, I would assume that the following are...
  2. R

    Comparing means with zero-inflated data in SPSS

    Hi everybody, I whish to know how to compare means with zero-inflated data. I tried to perform an ANOVA test but obviosuly it's impossible since some treatments are very rich in zeros. How can I accomplish this task using SPSS? Thanks a lot!