將第一列的行值轉換爲R中的列

Question

我有以下數據框。

Student Score 
Thomas  23.6 
Sally  28.1 
Chris  27.9 
Morrison 32.5 
Thomas  30.3 
Sally  54.2 
Morrison 44.3 
Chris  99.2 

如何轉換成

Thomas Sally Morrison Chris 
23.6  28.1  32.5  27.9 
30.3  54.2  44.3  99.2 

注意：它不具備有以上數據幀的確切順序。

我試着用reshape2，reshape，dcast，melt，cbind等來改變它，我找不到任何有用的東西。

Answer 1

在reshape2包中使用dcast函數。

d1 <- read.table(text="Student Score 
Thomas  23.6 
Sally  28.1 
Chris  27.9 
Morrison 32.5 
Thomas  30.3 
Sally  54.2 
Morrison 44.3 
Chris  99.2", head=T, as.is=T) 

library(dplyr) 

d2 <- d1 %>% group_by(Student) %>% mutate(cn=1:n()) 

library(reshape2) 

dcast(d2, cn~Student, value.var = "Score") 
# cn Chris Morrison Sally Thomas 
# 1 1 27.9  32.5 28.1 23.6 
# 2 2 99.2  44.3 54.2 30.3