subset factor?
On 2011-01-14 06:20, Sarah Goslee wrote:
Are you certain they are numeric? Have you tried str() on your data? Sarah
Silvano: As Sarah says, do str(dados) to see that 'doses' is NOT numeric. The error message is very clear; it tells you that 'doses' is a factor. My guess is that you imported your data from somewhere and somehow managed to import 'doses' as a factor. My advice is to ALWAYS do an str() after importing/changing data. Peter Ehlers
On Fri, Jan 14, 2011 at 9:08 AM, Silvano<silvano at uel.br> wrote:
Hi, I used subset command, like this: grupoP = subset(dados, grupos=='P', select=c(mortos, vivos, doses, percevejos, p)) and the variables in select option are numeric. I tried fit a model with command: ajuste.logit = glm(cbind(mortos,percevejos)~log10(doses), family=binomial(logit), data=grupoP) and the output is:
ajuste.logit = glm(cbind(mortos,percevejos)~log10(doses), family=binomial(logit), data=grupoP)
Erro em Math.factor(doses) : log10 not meaningful for factors what is wrong with my commands? Why doses aren't numeric? Thanks,