我有一个dplyr::summarize函数。我如何向其交出多个变量？
示例：
myfunction <- function(mydf, grp) {
library(dplyr)
grp <- enquo(grp)
result <- mydf %>%
group_by(!! grp) %>%
summarise(sum = sum(x))
result
}
# works
myfunction(df, grp1)
# doesn't work
myfunction(df, c(grp1, grp2))
答案 0 :(得分：2)
如果我们传递多个变量，则将其作为字符串传递并使用player1 = 50
player2 = 50
while player1 >= 0 or player2 >= 0:
import random
slash = random.randint(5, 9)
stab = random.randint(1, 15)
swing = random.randint(15, 20)
heal = random.randint(10, 15)
a = [slash, stab, swing]
ai = random.choice(a)
hit1 = input("Press 1 2 3 or 4")
if hit1 == "1":
print("You dealt " + str(slash))
player2 = player2 - slash
print("Player 2 now has " + str(player2))
if hit1 == "2":
print("You dealt " + str(stab))
player2 = player2 - stab
print("Player 2 now has " + str(player2))
if hit1 == "3":
print("You dealt " + str(swing))
player2 = player2 - swing
print("Player 2 now has " + str(player2))
if hit1 == "4":
print("You healed by " + str(heal))
player2 = player1 + heal
print("Player 1 now has " + str(player1))
hit2 = print("player 2 has dealt " + str(ai))
player1 = player1 - ai
print("player1 is now on " +str(player1))
group_by_at以防万一，我们希望通过OP帖子中所示的组，一种方法是使用myfunction <- function(mydf, grp, xvar) {
mydf %>%
group_by_at(grp) %>%
summarise(sum = sum({{xvar}}))
}
myfunction(mtcars, "am", mpg)
# A tibble: 2 x 2
# am sum
# <dbl> <dbl>
#1 0 326.
#2 1 317.
myfunction(mtcars, c("am", "gear"), mpg)
# A tibble: 4 x 3
# Groups: am [2]
# am gear sum
# <dbl> <dbl> <dbl>
#1 0 3 242.
#2 0 4 84.2
#3 1 4 210.
#4 1 5 107.
进行转换并求值（enexpr）
!!!