Question

我有一个看起来像这样的数据框（参见链接）。我想获取下面产生的输出，并通过在n和平均变量上扩展色调变量更进一步。看起来这个主题可能对此有所影响，但我无法让它起作用： Is it possible to use spread on multiple columns in tidyr similar to dcast?

我希望最终表将源变量放在一列中，然后将tone-n和tone-avg变量放在列中。所以我希望列标题为“source” - “For - n” - “Against - n”“For -Avg” - “Against - Avg”。这是出版物，不是为了进一步计算，所以它是关于呈现数据。以这种方式呈现数据对我来说似乎更直观。谢谢。

#variable1
Politician.For<-sample(seq(0,4,1),50, replace=TRUE)
#variable2
Politician.Against<-sample(seq(0,4,1),50, replace=TRUE)
#Variable3
Activist.For<-sample(seq(0,4,1),50,replace=TRUE)
#variable4
Activist.Against<-sample(seq(0,4,1),50,replace=TRUE)
#dataframe
df<-data.frame(Politician.For, Politician.Against, Activist.For,Activist.Against)

#tidyr
df %>%
 #Gather all columns 
 gather(df) %>%
 #separate by the period character 
 #(default separation character is non-alpha numeric characterr) 
 separate(col=df, into=c('source', 'tone')) %>%
 #group by both source and tone  
 group_by(source,tone) %>%
 #summarise to create counts and average
 summarise(n=sum(value), avg=mean(value)) %>%
 #try to spread
 spread(tone, c('n', 'value'))

Answer 1

我认为你想要的是另一个聚集来打破计数，并将其作为单独的观察，即gather(type, val, -source, -tone)。

gather(df, who, value) %>%
    separate(who, into=c('source', 'tone')) %>%
    group_by(source, tone) %>%
    summarise(n=sum(value), avg=mean(value)) %>%
    gather(type, val, -source, -tone) %>%
    unite(stat, c(tone, type)) %>%
    spread(stat, val)

产量

Source: local data frame [2 x 5]

      source Against_avg Against_n For_avg For_n
1   Activist        1.82        91    1.84    92
2 Politician        1.94        97    1.70    85

Answer 2

使用data.table语法（感谢@akrun）：

library(data.table)
dcast(
  setDT(melt(df))[,c('source', 'tone'):=
      tstrsplit(variable, '[.]')
    ][,list(
      N  = sum(value),
      avg= mean(value))
    ,by=.(source, tone)],
  source~tone,
  value.var=c('N','avg'))

使用spread来创建带有tidyr

2 个答案: