用常数分隔列并将其压缩到R data.frame中的一行 [英] Separate columns with constant numbers and condense them to one row in R data.frame

问题描述

我有一个名为 d 的data.frame。在此data.frame中，某些列由第一列各行中的常数组成： study.name （请参见下文）。

I have a data.frame called d. In this data.frame, some columns consist of constant numbers across the rows of the first column: study.name (see below).

例如，列 ESL ， ESL.1 ， prof 和 prof.1 是 Shin.Ellis 的所有行的常数，并且也是常数对于 Trus.Hsu 的所有行，等等。

For example, columns ESL, ESL.1, prof, and prof.1 are constant numbers for all rows of Shin.Ellis and also constant for all rows of Trus.Hsu and so on.

Q： 在BASE R中，如何分隔这样的常量变量，然后仅用一个数字将它们压缩为一行？

Q: In BASE R, how can I separate such constant variables, and then condense them to one row with only one number?

我想要的输出如下所示。功能性的答案值得赞赏。

My desired output is shown further below. A functional answer is appreciated.

d <- read.csv("https://raw.githubusercontent.com/izeh/m/master/irr.csv", h = T)[-(2:3)]

## FIRST 8 ROWS:

#    study.name ESL prof scope type ESL.1 prof.1 scope.1 type.1
# 1  Shin.Ellis   1    2     1    1     1      2       1      1
# 2  Shin.Ellis   1    2     1    1     1      2       1      1
# 3  Shin.Ellis   1    2     1    2     1      2       1      1
# 4  Shin.Ellis   1    2     1    2     1      2       1      1
# 5  Shin.Ellis   1    2    NA   NA     1      2      NA     NA
# 6  Shin.Ellis   1    2    NA   NA     1      2      NA     NA
# 7    Trus.Hsu   2    2     2    1     2      2       1      1
# 8    Trus.Hsu   2    2    NA   NA     2      2      NA     NA

所需的输出：

#    study.name ESL prof  ESL.1 prof.1 
# 1  Shin.Ellis   1    2      1      2  
# 2  Trus.Hsu     2    2      2      2
# .     .         .    .      .      . # AND SO ON !!!

推荐答案

也许我们需要

library(dplyr)
d %>%
   group_by(study.name) %>%
   slice(1)

---

或以为基础R 按'study.name'分组后，在指定 na.action = NULL 的同时获取第一行，因为默认选项为 na.omit 可以省略任何列中具有 NA 的行

---

Or in base R after grouping by 'study.name', get the first row while specifying the na.action = NULL as the default option is na.omit which can omit any row having NA in any of the columns

aggregate(.~ study.name, d, head, 1, na.action = NULL)

如果我们想对列进行子集化

If we want to subset the columns

nm1 <- names(which(!colSums(!do.call(rbind, by(d[-1], d$study.name,
     FUN = function(x) lengths(sapply(x, unique)) == 1)))))
unique(d[c("study.name", nm1)])

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