R每行的计数速度非常慢
我试图获得每行数据帧中出现的所有值,如下所示:R每行的计数速度非常慢,r,dataframe,dplyr,R,Dataframe,Dplyr,我试图获得每行数据帧中出现的所有值,如下所示: a b c d e 1 1 1 0 -1 NA 2 0 -1 -1 1 NA 3 -1 0 NA NA 1 对此 a b c d e count.-1 count.0 count.1 count.NA 1 1 1 0 -1 NA 1 1 2 1 2 0 -1 -1 1 NA 2
a b c d e
1 1 1 0 -1 NA
2 0 -1 -1 1 NA
3 -1 0 NA NA 1
对此
a b c d e count.-1 count.0 count.1 count.NA
1 1 1 0 -1 NA 1 1 2 1
2 0 -1 -1 1 NA 2 1 1 1
3 1 0 NA NA 1 0 1 2 2
我现在就是这样做的:
df = df %>%
by_row(
..f = function(x) {
sum(is.na(x[1:8]))
},
.to = "count_na",
.collate = "cols"
) %>%
by_row(
..f = function(x) {
sum(x[1:8] == 1, na.rm = T)
},
.to = "count_positive",
.collate = "cols"
) %>%
by_row(
..f = function(x) {
sum(x[1:8] == -1, na.rm = T)
},
.to = "count_negative",
.collate = "cols"
) %>%
by_row(
..f = function(x) {
sum(x[1:8] == 0, na.rm = T)
},
.to = "count_neutral",
.collate = "cols"
)
但问题是,对于5 mil行,这需要永远完成(超过3个小时,有没有更好的方法来完成?您可以利用
数据表
进行快速处理。首先,将其分解为一个长格式,然后在返回并合并之前按行号和值制表,以获得所需的输出
agg <- dcast(melt(DT[, rn:=.I], id.vars="rn")[, .N, by=.(rn, value)],
rn ~ value, sum, value.var="N")
DT[agg, on=.(rn)]
时间:
Unit: seconds
expr min lq mean median uq max neval
dtmtd() 10.07663 10.14351 10.17387 10.2104 10.22249 10.23458 3
可能重复,效率不高,但应该比当前版本快。请尝试cbind(df1,t(apply(df1,1,table,exclude=NULL))
dtmtd <- function() {
agg <- dcast(melt(DT[, rn:=.I], id.vars="rn")[, .N, by=.(rn, value)],
rn ~ value, sum, value.var="N")
DT[agg, on=.(rn)]
}
microbenchmark::microbenchmark(dtmtd(), times=3L)
Unit: seconds
expr min lq mean median uq max neval
dtmtd() 10.07663 10.14351 10.17387 10.2104 10.22249 10.23458 3