既然你想在每個狀態的基礎上tapply
結果可能是你想要的。
爲了說明,讓我們產生一些任意的數據一起玩:
set.seed(349) # For replication
n <- 20000 # Sample size
gender <- sample(c('M', 'W'), size = n, replace = TRUE) # Random selection of gender
state <- c('AL','AK','AZ','AR','CA','CO','CT','DE','DC','FL','GA','HI',
'ID','IL','IN','IA','KS','KY','LA','ME','MD','MA','MI','MN',
'MS','MO','MT','NE','NV','NH','NJ','NM','NY','NC','ND','OH',
'OK','OR','PA','RI','SC','SD','TN','TX','UT','VT','VA','WA',
'WV','WI','WY') # All US states
state <- sample(state, size = n, replace = TRUE) # Random selection of the states
state_index <- tapply(state, state) # Just for the data generatino part ...
gender_index <- tapply(gender, gender)
# Generate salaries
salary <- runif(length(unique(state)))[state_index] # Make states different
salary <- salary + c(.02, -.02)[gender_index] # Make gender different
salary <- salary + log(50) + rnorm(n) # Add mean and error term
salary <- exp(salary) # The variable of interest
你問,薪金爲每個州婦女總和與總工資的每個州的總和是什麼:
salary_w <- tapply(salary[gender == 'W'], state[gender == 'W'], sum)
salary_total <- tapply(salary, state, sum)
或者如果它是在一個數據幀:
salary_w <- with(myData, tapply(salary[gender == 'W'], state[gender == 'W'], sum))
salary_total <- with(myData, tapply(salary, state, sum))
那麼答案是:
> salary_w/salary_total
AK AL AR AZ CA CO CT DC
0.4667424 0.4877013 0.4554831 0.4959573 0.5382478 0.5544388 0.5398104 0.4750799
DE FL GA HI IA ID IL IN
0.4684846 0.5365707 0.5457726 0.4788805 0.5409347 0.4596598 0.4765021 0.4873932
KS KY LA MA MD ME MI MN
0.5228247 0.4955802 0.5604342 0.5249406 0.4890297 0.4939574 0.4882687 0.5611435
MO MS MT NC ND NE NH NJ
0.5090843 0.5342312 0.5492702 0.4928284 0.5180169 0.5696885 0.4519603 0.4673822
NM NV NY OH OK OR PA RI
0.4391634 0.4380065 0.5366625 0.5362918 0.5613301 0.4583937 0.5022793 0.4523672
SC SD TN TX UT VA VT WA
0.4862358 0.4895377 0.5048047 0.4443220 0.4881062 0.4880047 0.5338397 0.5136393
WI WV WY
0.4787588 0.5495602 0.5029816
相關問題[這裏](http://stackoverflow.com/questions/4337170/calculating-subtotals-in-r) – Chase 2010-12-03 02:57:05