How to do specific, custom contrasts in EMMEANs with multiple nested factor levels but without subsetting data
问题 Here is my data frame (my real DF has way more data points): rearing.temp<-c("15", "15", "15", "15", "19", "19", "19", "19") source<-c("field", "field", "woods", "woods", "field", "field", "woods", "woods") runway.temp<-c("40","20","40","20","40","20","40","20") velocity<-c("2.3", "2.1", "1.9", "1.9", "2.3", "2.2", "2.3", "2.0") snail<-data.frame(rearing.temp, source, runway.temp, velocity) Here is my model: mod <- lmer(velocity ~ runway.temp*source*rearing.temp + (1|family) + (1|collection