r - 将 data.frame 转换为单行

Question

我有这些数据:

structure(list(type = c("journal", "all", "similar_age_1m", "similar_age_3m", 
"similar_age_journal_1m", "similar_age_journal_3m"), count = c("13972", 
"754555", "22408", "56213", "508", "1035"), rank = c("13759", 
"754043", "22339", "56074", "459", "947"), pct = c("98.48", "99.93", 
"99.69", "99.75", "90.35", "91.50")), .Names = c("type", "count", 
"rank", "pct"), row.names = c(NA, -6L), class = "data.frame")

我想将其转换为单行，列名 2:4 加上相应类型的前缀。例如journal.count、journal.rank ...最快的方法是什么？由于某种原因，dcast 和 reshape 没有为我做这件事，我的解决方案有点太麻烦了。

Answer 1

您提到了reshape2，所以这是一种方法:

library("reshape2")
dcast(melt(dat, id.var="type"), 1~variable+type)

这给出了:

  1 count_all count_journal count_similar_age_1m count_similar_age_3m
1 1    754555         13972                22408                56213
  count_similar_age_journal_1m count_similar_age_journal_3m rank_all
1                          508                         1035   754043
  rank_journal rank_similar_age_1m rank_similar_age_3m
1        13759               22339               56074
  rank_similar_age_journal_1m rank_similar_age_journal_3m pct_all pct_journal
1                         459                         947   99.93       98.48
  pct_similar_age_1m pct_similar_age_3m pct_similar_age_journal_1m
1              99.69              99.75                      90.35
  pct_similar_age_journal_3m
1                      91.50

不过，类型和变量是用_分隔的，而不是.。