我有一个名为的数据框df
:
City,State,Price,Dogs
Portland,OR,75,1
Portland,OR,100,3
San Diego,CA,12,4
San Diego,CA,23,5
...
I used dplyr
's summarise
and group_by
功能...
df.median <- summarise(
group_by(
df,
State,
City
),
MEDIAN_PRICE = median(Price),
SUM_DOGS = sum(Dogs)
)
但当我跑步时top_n(df.median, 100, SUM_DOGS)
, R 没有给我 100 个最高值的城市SUM_DOGS
。它只是返回df.median
.
Why?