R 在变量的唯一组合之间对观察次数的子集数据

我有这样一个数据帧：

descriptionin = c("sample1","sample1","sample1","sample1","sample1","sample1","sample1","sample1","sample2","sample2","sample3","sample3","sample3","sample3","sample3","sample3")
dilutionin = c(1,10,100,1000,1,10,100,1000,5,5,2,8,32,2,8,32)
conditionin = c("cond1","cond1","cond1","cond1","cond2","cond2","cond2","cond2","cond1","cond2","cond1","cond1","cond1","cond2","cond2","cond2")

testin <- data.frame(descriptionin,dilutionin,conditionin)

descriptionin=c（“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本1”、“样本2”、“样本3”、“样本3”、“样本3”、“样本3”、“样本3”）
稀释度n=c（1,101001000,1,101001000,5,5,2,8,32,2,8,32）
conditin=c（“cond1”、“cond1”、“cond1”、“cond1”、“cond2”、“cond2”、“cond1”、“cond2”、“cond1”、“cond1”、“cond2”、“cond2”）
testin一个选项是
data.table
。将“data.frame”转换为“data.table”（
setDT（testin）
），按“descriptionin”和“conditionin”分组，我们可以找到组中元素的行索引（
.I
），这些元素有多个
唯一的
'dilutionin'，并使用该索引对行进行子集划分

library(data.table)
setDT(testin)[testin[, .I[uniqueN(dilutionin)>1], .(descriptionin, conditionin)]$V1]

谢谢除了$V1？@AwesomeeExpress之外，我通过使用
.I
，创建了一个列，默认名称为
V1'，其中包含行索引，我们通过
$V1`提取该列，并使用它来子集数据集的行。明白了吗！再次感谢
library(data.table)
setDT(testin)[testin[, .I[uniqueN(dilutionin)>1], .(descriptionin, conditionin)]$V1]