在R中读取两行标题 [英] Reading two-line headers in R

问题描述

这种情况一直发生在我身上，就像人们一样通常使用一行作为列名称，然后在其下面包含另一行作为度量单位。我不想跳过任何东西。我想要名称和单位通过。

这是什么具有两个头文件的典型文件可能看起来像：

$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ t $生物质产量
作物Mg /公顷
C2 17.76 205.92
C2 17.96 207.86
CC 17.72 197.22
CC 18.42 205.20
CCW 18.15 200.51
CCW 17.45 190.59
P 3.09 0.00
P 3.34 0.00
S2 5.13 49.68
S2 5.36 49.72

解决方案

我会做两个步骤，假设我们知道第一行包含标签，并且总是有两个标头。

 标题<  -  scan（file.txt，nlines = 1，what = character（））
 data < -  read.table（file.txt ，skip = 2，header = FALSE）
  

然后添加字符向量头作为名称组件ent：

  names（data）<  -  header 
   
 
 
头<  - 扫描（ data.txt，nlines = 1，what = character（））
 data < -  read.table（data.txt，skip = 2，header = FALSE）
名称（数据）< ;  -  header 
 
 head（data）
 
> （数据）
 trt生物量收益
 1 C2 17.76 205.92 
 2 C2 17.96 207.86 
 3 CC 17.72 197.22 
 4 CC 18.42 205.20 
 5 CCW 18.15 200.51 
 CCW 17.45 190.59 
  
如果你想要单位，按照@Dinin的答案，然后在第二行做第二个 scan（） 
 
 
  header2<扫描（data.txt，skip = 1，nlines = 1，what = character（））
名称（数据）<  -  paste0（header，header2）
 
> （数据）
 trtcrop生物量mg / ha yieldbu / ac 
 1 C2 17.76 205.92 
 2 C2 17.96 207.86 
 3 CC 17.72 197.22 
 4 CC 18.42 205.20 
 5 CCW 18.15 200.51 
 6 CCW 17.45 190.59 
  
 
What is the best way to read a file into R when the header has two necessary lines for the header?

This happens to me all the time, as people often use one line for the column name and then include another line underneath it for the unit of measurement.  I don't want to skip anything.  I want the names and the units to carry through.

Here is what a typical file with two headers might look like:
trt   biomass    yield
crop    Mg/ha    bu/ac
C2      17.76   205.92
C2      17.96   207.86
CC      17.72   197.22
CC      18.42   205.20
CCW     18.15   200.51
CCW     17.45   190.59
P       3.09    0.00
P       3.34    0.00
S2      5.13    49.68
S2      5.36    49.72

解决方案
I would do two steps, assuming we know that the first row contains the labels, and there are always two headers.
header <- scan("file.txt", nlines = 1, what = character())
data <- read.table("file.txt", skip = 2, header = FALSE)
Then add the character vector header on as the names component:
names(data) <- header
For your data this would be
header <- scan("data.txt", nlines = 1, what = character())
data <- read.table("data.txt", skip = 2, header = FALSE)
names(data) <- header

head(data)

>     head(data)
  trt biomass  yield
1  C2   17.76 205.92
2  C2   17.96 207.86
3  CC   17.72 197.22
4  CC   18.42 205.20
5 CCW   18.15 200.51
6 CCW   17.45 190.59
If you want the units, as per @DWin's answer, then do a second scan() on line 2
header2 <- scan("data.txt", skip = 1, nlines = 1, what = character())
names(data) <- paste0(header, header2)

> head(data)
  trtcrop biomassMg/ha yieldbu/ac
1      C2        17.76     205.92
2      C2        17.96     207.86
3      CC        17.72     197.22
4      CC        18.42     205.20
5     CCW        18.15     200.51
6     CCW        17.45     190.59


                        
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