问题
I'm performing the same regression on several different datasets (same dependent and independe variables). However, there are many independent variables, and I often want to test adding/removing different variables. I'd like to avoid making all these changes to different lines of code, just because they use different datasets. Can I instead just copy the formula that was used to create some object, and then create a new object using a different dataset? For example, something like:
fit1 <- lm(y ~ x1 + x2 + x3 + ..., data = dataset1)
fit2 <- lm(fit1$call, data = dataset2) # this doesn't work
fit3 <- lm(fit1$call, data = dataset3) # this doesn't work
This way, if I want to update numerous regressions, I just update the first one and then rerun them all.
Can this be done? Preferably without using a loop or paste().
Thanks!
回答1:
Or use update
(fit <- lm(mpg ~ wt, data = mtcars))
# Call:
# lm(formula = mpg ~ wt, data = mtcars)
#
# Coefficients:
# (Intercept) wt
# 37.285 -5.344
update(fit, data = mtcars[mtcars$hp < 100, ])
# Call:
# lm(formula = mpg ~ wt, data = mtcars[mtcars$hp < 100, ])
#
# Coefficients:
# (Intercept) wt
# 39.295 -5.379
update(fit, data = mtcars[1:10, ])
# Call:
# lm(formula = mpg ~ wt, data = mtcars[1:10, ])
#
# Coefficients:
# (Intercept) wt
# 33.774 -4.285
回答2:
Collect your datasets into a list
and then use lapply
. E.g.:
dsets <- list(dataset1,dataset2,dataset3)
lapply(dsets, function(x) lm(y ~ x1 + x2, data=x) )
回答3:
Not sure entirely that this what you want but you can do this as follows:
formula <- y ~ x1 + x2 + x3 + ...
fit1 <- lm(formula, data = dataset1)
fit2 <- lm(formula, data = dataset2)
fit3 <- lm(formula, data = dataset3)
来源:https://stackoverflow.com/questions/23964993/easily-performing-the-same-regression-on-different-datasets