資料結構
網路
關係型資料庫管理系統
作業系統
Java
MS Excel
iOS
HTML
CSS
Android
Python
C 程式設計
C++
C#
MongoDB
MySQL
Javascript
PHP
物理學
化學
生物學
數學
英語
經濟學
心理學
社會學
服裝設計
法律研究如何在 R 資料框中建立包含各行最大字串值的列？
要建立一列包含各行最大字串值的列，我們可以使用 apply 函式，並透過建立函式來定義最大值的字串大小，如下面的示例所示。如果所有列的字元數相同或存在一些相同的值，則輸出將是第一個。
示例 1
考慮以下資料框 -
x1<−sample(c("UK","USA","India"),20,replace=TRUE)
x2<−sample(c("China","Egypt"),20,replace=TRUE)
df1<−data.frame(x1,x2)
df1輸出
x1 x2 1 India China 2 India Egypt 3 India Egypt 4 India China 5 USA China 6 UK Egypt 7 UK Egypt 8 UK Egypt 9 India Egypt 10 India China 11 USA China 12 India China 13 India Egypt 14 UK China 15 India China 16 UK China 17 India China 18 UK China 19 USA China 20 USA China
在 df1 的每一行建立包含最大文字的列 -
示例
df1$LargeText <− apply(df1,1, function(x) x[which.max(nchar(x))]) df1
輸出
x1 x2 LargeText 1 India China India 2 India Egypt India 3 India Egypt India 4 India China India 5 USA China China 6 UK Egypt Egypt 7 UK Egypt Egypt 8 UK Egypt Egypt 9 India Egypt India 10 India China India 11 USA China China 12 India China India 13 India Egypt India 14 UK China China 15 India China India 16 UK China China 17 India China India 18 UK China China 19 USA China China 20 USA China China
示例 2
y1<−sample(c("Female","Male"),20,replace=TRUE)
y2<−sample(c("Female","Male"),20,replace=TRUE)
df2<−data.frame(y1,y2)
df2輸出
y1 y2 1 Male Female 2 Male Female 3 Female Male 4 Female Male 5 Female Female 6 Female Male 7 Male Male 8 Female Female 9 Female Female 10 Female Female 11 Male Male 12 Male Female 13 Male Male 14 Male Female 15 Female Male 16 Female Female 17 Male Female 18 Female Female 19 Female Male 20 Female Female
在 df2 的每一行建立包含最大文字的列 -
示例
df2$LargeText<−apply(df2,1, function(x) x[which.max(nchar(x))]) df2
輸出
y1 y2 LargeText 1 Male Female Female 2 Male Female Female 3 Female Male Female 4 Female Male Female 5 Female Female Female 6 Female Male Female 7 Male Male Male 8 Female Female Female 9 Female Female Female 10 Female Female Female 11 Male Male Male 12 Male Female Female 13 Male Male Male 14 Male Female Female 15 Female Male Female 16 Female Female Female 17 Male Female Female 18 Female Female Female 19 Female Male Female 20 Female Female Female
更新於: 2021 年 2 月 9 日
114 次瀏覽
廣告