Question

现在我假设有下表：

.1 .2 .3
.2 1 C
.2 1 C
.2 1 C
.3 1 N
.3 1 N
.4 1 N
.4 1 N
.4 1 N
.4 1 N

鉴于列2相同且列1的值不同，我们只想保留列3包含C的行。这应该产生下表：

.1 .2 .3
.2 1 C
.2 1 C
.2 1 C

我已经看过以下问题：
Remove duplicates based on 2nd column condition
R, conditionally remove duplicate rows
Conditionally removing duplicates in R

您知道如何实现这一目标吗？

Answer 1

我不确定我是否完全理解您需要做什么，但这是尝试使用简单的If语句来检查两列的差异，即

if (var(dd3$X1) != 0 & var(dd3$X2) == 0) { dd3 <- subset(dd3, X3 == 'C')}
dd3
#  X1 X2 X3
#1  2  1  C
#2  2  1  C
#3  2  1  C

哪里

dput(dd3)
structure(list(X1 = c(2L, 2L, 2L, 3L, 3L, 4L, 4L, 4L, 4L), X2 = c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), X3 = structure(c(1L, 1L, 1L, 
2L, 2L, 2L, 2L, 2L, 2L), .Label = c("C", "N"), class = "factor")), class = "data.frame", row.names = c(NA, -9L))

Answer 2

“如果第2列相同，”我并不完全理解您的意思。您可以使用subset

subset(df, df$col3 == "C" & df$col1 != df$col2)

我使用col1，col2和col3作为标题

Answer 3

也许您可以使用ave尝试以下基本R代码，即

dfout <- subset(df,as.logical(ave(X3,X1,X2,FUN = function(v) v=="C")))

# > dfout
#    X1 X2 X3
# 1  2  1  C
# 2  2  1  C
# 3  2  1  C

数据

df <- structure(list(X1 = c(2L, 2L, 2L, 3L, 3L, 4L, 4L, 4L, 4L), X2 = c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), X3 = c("C", "C", "C", "N", "N", 
"N", "N", "N", "N")), row.names = c(NA, -9L), class = "data.frame")

根据R中的几个条件有条件地删除重复项

3 个答案: