当所有值都位于R中数据帧的同一列时,计算百分比
我有以下数据框当所有值都位于R中数据帧的同一列时,计算百分比,r,percentage,R,Percentage,我有以下数据框 x <- data.frame("treatment"= c(1, 1, 1, 1, 2, 2, 2, 2), "Time" = c(0, 30, 60, 180, 0, 30, 60, 180), "cells_alive" = c(500, 470, 100, 20, 476, 310, 99, 2)) x使用数据表 library(data.tab
x <- data.frame("treatment"= c(1, 1, 1, 1, 2, 2, 2, 2),
"Time" = c(0, 30, 60, 180, 0, 30, 60, 180),
"cells_alive" = c(500, 470, 100, 20, 476, 310, 99, 2))
x使用数据表
library(data.table)
setDT(x) #converting x to data.table
x[,.(Time, value = cells_alive / cells_alive[which(Time == 0)]),treatment]
#output
treatment Time value
1: 1 0 1.000000000
2: 1 30 0.940000000
3: 1 60 0.200000000
4: 1 180 0.040000000
5: 2 0 1.000000000
6: 2 30 0.651260504
7: 2 60 0.207983193
8: 2 180 0.004201681
发布dplyr
和data.table
版本后,为了完整起见,这里有一个不需要安装软件包的版本:
stack(tapply(x$cells_alive, x$treatment, function(ca) ca / ca[1] ))
给
> stack(tapply(x$cells_alive, x$treatment, function(ca) ca / ca[1] ))
values ind
1 1.000000000 1
2 0.940000000 1
3 0.200000000 1
4 0.040000000 1
5 1.000000000 2
6 0.651260504 2
7 0.207983193 2
8 0.004201681 2
谢谢,效果很好!现在,如果我在治疗中也有复制,它会如何工作?
> stack(tapply(x$cells_alive, x$treatment, function(ca) ca / ca[1] ))
values ind
1 1.000000000 1
2 0.940000000 1
3 0.200000000 1
4 0.040000000 1
5 1.000000000 2
6 0.651260504 2
7 0.207983193 2
8 0.004201681 2