r - 在数字数据帧中添加字符串并连接两个字符串数据帧

Question

这个问题在这里已经有了答案:

Paste together two dataframes element by element (5 个回答)

关闭 2 年前。

我有两个数字数据帧，具有对数倍数变化 (LFC) 的 df1 和具有 p 值的 df2。

df1 = data.frame(V1=c(1.2, 1.5, 0.3),
                 V2=c(0.5, 0.9, 1.1),
                 V3=c(-0.9, -1.5, -0.4))

df2 = data.frame(Y1=c(0.02, 0.005, 0.06),
                 Y2=c(0.05, 0.009, 0.01),
                 Y3=c(0.01, 0.001, 0.1))

出于某些演示目的，我想在 df1 中添加前缀“LFC =”，在 df2 中添加前缀“p =”，以便得到以下内容:

df1

V1           V2           V3
LFC = 1.2    LFC = 0.5    LFC = -0.9
LFC = 1.5,   LFC = 0.9    LFC = -1.5
LFC = 0.3    LFC = 1.1    LFC = -0.4


df2

Y1           Y2            Y3
p = 0.02     p = 0.05      p = 0.01
p = 0.005    p = 0.009     p = 0.001
p = 0.06     p = 0.01      p = 0.1

并最终将它们连接起来以获得结构如下的 3x3 数据框:

df3

V1           V2           V3
LFC = 1.2,   LFC = 0.5,   LFC = -0.9,
p = 0.02     p = 0.05     p = 0.01

LFC = 1.5,   LFC = 0.9,   LFC = -1.5
p = 0.005    p = 0.009    p = 0.001

LFC = 0.3,   LFC = 1.1,   LFC = -0.4,
p = 0.06     p = 0.01     p = 0.1

在这里做什么？感谢您的解决方案。

Answer 1

一种方法是粘贴前缀和Map，即

Map(`rbind`, lapply(df1, function(i)paste0('LFC = ', i)), 
             lapply(df2, function(i) paste0('p = ', i)))

给出，

$V1
     [,1]        [,2]        [,3]       
[1,] "LFC = 1.2" "LFC = 1.5" "LFC = 0.3"
[2,] "p = 0.02"  "p = 0.005" "p = 0.06" 

$V2
     [,1]        [,2]        [,3]       
[1,] "LFC = 0.5" "LFC = 0.9" "LFC = 1.1"
[2,] "p = 0.05"  "p = 0.009" "p = 0.01" 

$V3
     [,1]         [,2]         [,3]        
[1,] "LFC = -0.9" "LFC = -1.5" "LFC = -0.4"
[2,] "p = 0.01"   "p = 0.001"  "p = 0.1"   

如果你想要一个矩阵(或数据框)而不是列表，那么只需使用 mapply 而不是 Map，即

mapply(`rbind`, lapply(df1, function(i)paste0('LFC = ', i)), 
                lapply(df2, function(i) paste0('p = ', i)))

      V1          V2          V3          
[1,] "LFC = 1.2" "LFC = 0.5" "LFC = -0.9"
[2,] "p = 0.02"  "p = 0.05"  "p = 0.01"  
[3,] "LFC = 1.5" "LFC = 0.9" "LFC = -1.5"
[4,] "p = 0.005" "p = 0.009" "p = 0.001" 
[5,] "LFC = 0.3" "LFC = 1.1" "LFC = -0.4"
[6,] "p = 0.06"  "p = 0.01"  "p = 0.1"

你也可以paste代替rbind，即

 mapply(`paste`, lapply(df1, function(i)paste0('LFC = ', i)), 
                 lapply(df2, function(i) paste0('p = ', i)))

     V1                    V2                    V3                    
[1,] "LFC = 1.2 p = 0.02"  "LFC = 0.5 p = 0.05"  "LFC = -0.9 p = 0.01" 
[2,] "LFC = 1.5 p = 0.005" "LFC = 0.9 p = 0.009" "LFC = -1.5 p = 0.001"
[3,] "LFC = 0.3 p = 0.06"  "LFC = 1.1 p = 0.01"  "LFC = -0.4 p = 0.1"