【发布时间】:2016-05-31 21:27:09
【问题描述】:
如何按“id”分组,将一些算术函数应用于最后四列(按组),并将新行添加到包含结果的 df。这是一个有 5 个样本 (id) 和 8 列的说明性示例:
d1 d2 id type treat v1_gm v2_pct v3_pct
1 info info 1 leaf NA 0.2 70 90
2 info info 1 flower A 0.5 80 80
3 info info 2 leaf NA 0.4 65 80
4 info info 2 flower A 0.1 90 90
5 info info 3 leaf NA 0.6 55 80
6 info info 3 stem A 0.3 80 30
7 info info 4 leaf NA 0.6 30 40
8 info info 4 flower A 0.7 75 75
9 info info 5 leaf/stem NA 0.8 80 75
可重现的例子:
df <- data.frame(matrix(NA, nrow = 9, ncol = 8), row.names=NULL)
colnames(df) <- c("d1","d2","id","type","treat","v1_gm","v2_pct","v3_pct")
df$d1 <- "info"
df$d2 <- "info"
id <- c(1,1,2,2,3,3,4,4,5)
df$id <- c(1,1,2,2,3,3,4,4,5)
df$type <- c("leaf","flower","leaf","flower","leaf","stem","leaf","flower","leaf/stem")
df$treat <- c(NA,"A",NA,"A",NA,"A",NA,"A",NA)
df$v1_gm <- c(0.2,0.5,0.4,0.1,0.6,0.3,0.6,0.7,0.8)
df$v2_pct <- c(70,80,65,90,55,80,30,75,80)
df$v3_pct <- c(90,80,80,90,80,30,40,75,75)
结果表应如下所示。第 3、6、9 和 13 行是包含结果的新行。新行可以附加在表的末尾,或者放入一个 tmp df 以便稍后使用 rbind 添加(无论哪种方式,我都不知道该怎么做)。分组变量是列“id”。函数 sum 用于“v1_gm”。函数“mean”用于多个连续列,此处为“v1_pct”和“v3_pct”,应按名称调用(例如,v1_pct:v3_pct)。新行中“type”的值与组行中的“type”连接,“d1”和“d2”简单地从其中treat=="A"的组行中复制,新行中的“treat”行被赋值为“cmb”。
d1 d2 id type treat v1_gm v2_pct v3_pct
1 info info 1 leaf NA 0.2 70 90
2 info info 1 flower A 0.5 80 80
3 info info 1 leaf/flower cmb 0.7 75 85
4 info info 2 leaf NA 0.4 65 80
5 info info 2 flower A 0.1 90 90
6 info info 2 leaf/flower cmb 0.5 77.5 85
7 info info 3 leaf NA 0.6 55 80
8 info info 3 stem A 0.3 80 30
9 info info 3 leaf/stem cmb 0.9 67.5 55
10 info info 4 leaf NA 0.6 30 40
11 info info 4 flower A 0.7 75 75
13 info info 4 leaf/flower cmb 1.3 52.5 57.5
14 info info 5 leaf/stem NA 0.8 80 75
【问题讨论】:
标签: r dplyr group-summaries