「'到'缺少'在單獨的列（tidyr）

Question

我構建了10篇論文的元數據。該dput()結果介紹如下：

> dput(itemlist) 
structure(list(title = c("錢學森工程科學思想的實踐者 [科普文章]", 
"超高周疲勞裂紋萌生與初始擴展的特徵尺度 [科普文章]", "Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊論文]", 
"一種熱機械疲勞實驗的裝置和方法 [專利]", "IUTAM和ICTAM的起源和歷程 [科普文章]", 
"加載頻率對金屬材料超高周疲勞性能的影響 [會議論文]", "金屬材料超高周疲勞行爲的Monte-Carlo模擬 [會議論文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [會議論文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [會議論文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [會議論文]" 
), publish = c("2014", "2014", " 2013", "專利類型: 發明專利, 專利號: ZL2009102374751, 申請日期: 2012, 公開日期: 2012-12-27", 
"2012", "第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", 
"第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", "The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10" 
), author = c("丁雁生; 洪友士; 金和", "洪友士; 中國科學院老科技工作者協會工程力學分會", 
"Sih G C; Hong YS(洪友士)", "謝季佳; 趙愛國; 武曉東; 洪友士", 
"陳杰; 劉洋; 湯亞南; 洪友士", "趙愛國; 洪友士; 謝季佳", "雷錚強; 洪友士; 謝季佳; 趙愛國", 
"Zhang SY(張雙寅); Wang L(王雷); Hong YS(洪友士)", "Lei ZQ(雷錚強); Xie JJ(謝季佳); Zhao AG(趙愛國); Hong YS(洪友士)", 
"Wu XD(武曉東); Ge F(葛斐); Hong YS(洪友士)")), .Names = c("title", 
"publish", "author"), row.names = c(NA, 10L), class = "data.frame") 

我發現tidyr可以通過每個元素的一個屬性單獨的列表。在這個例子中，我「作者」分成不同的行：

> dput(itemlist_tidy) 
structure(list(title = c("錢學森工程科學思想的實踐者 [科普文章]", 
"錢學森工程科學思想的實踐者 [科普文章]", "錢學森工程科學思想的實踐者 [科普文章]", 
"超高周疲勞裂紋萌生與初始擴展的特徵尺度 [科普文章]", "超高周疲勞裂紋萌生與初始擴展的特徵尺度 [科普文章]", 
"Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊論文]", 
"Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊論文]", 
"一種熱機械疲勞實驗的裝置和方法 [專利]", "一種熱機械疲勞實驗的裝置和方法 [專利]", 
"一種熱機械疲勞實驗的裝置和方法 [專利]", "一種熱機械疲勞實驗的裝置和方法 [專利]", 
"IUTAM和ICTAM的起源和歷程 [科普文章]", "IUTAM和ICTAM的起源和歷程 [科普文章]", 
"IUTAM和ICTAM的起源和歷程 [科普文章]", "IUTAM和ICTAM的起源和歷程 [科普文章]", 
"加載頻率對金屬材料超高周疲勞性能的影響 [會議論文]", "加載頻率對金屬材料超高周疲勞性能的影響 [會議論文]", 
"加載頻率對金屬材料超高周疲勞性能的影響 [會議論文]", "金屬材料超高周疲勞行爲的Monte-Carlo模擬 [會議論文]", 
"金屬材料超高周疲勞行爲的Monte-Carlo模擬 [會議論文]", "金屬材料超高周疲勞行爲的Monte-Carlo模擬 [會議論文]", 
"金屬材料超高周疲勞行爲的Monte-Carlo模擬 [會議論文]", "Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [會議論文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [會議論文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [會議論文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [會議論文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [會議論文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [會議論文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [會議論文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [會議論文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [會議論文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [會議論文]" 
), publish = c("2014", "2014", "2014", "2014", "2014", " 2013", 
" 2013", "專利類型: 發明專利, 專利號: ZL2009102374751, 申請日期: 2012, 公開日期: 2012-12-27", 
"專利類型: 發明專利, 專利號: ZL2009102374751, 申請日期: 2012, 公開日期: 2012-12-27", 
"專利類型: 發明專利, 專利號: ZL2009102374751, 申請日期: 2012, 公開日期: 2012-12-27", 
"專利類型: 發明專利, 專利號: ZL2009102374751, 申請日期: 2012, 公開日期: 2012-12-27", 
"2012", "2012", "2012", "2012", "第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", 
"第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", "第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", 
"第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", "第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", 
"第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", "第十五屆全國疲勞與斷裂學術會議摘要及論文集, 中國廣東佛山", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10", 
"The 1st International Symposium on Archimedes Bridge, Qiandao Lake, China, 2010-10" 
), author = c("丁雁生", " 洪友士", " 金和", "洪友士", " 中國科學院老科技工作者協會工程力學分會", 
"Sih G C", " Hong YS(洪友士)", "謝季佳", " 趙愛國", " 武曉東", 
" 洪友士", "陳杰", " 劉洋", " 湯亞南", " 洪友士", "趙愛國", " 洪友士", 
" 謝季佳", "雷錚強", " 洪友士", " 謝季佳", " 趙愛國", "Zhang SY(張雙寅)", 
" Wang L(王雷)", " Hong YS(洪友士)", "Lei ZQ(雷錚強)", " Xie JJ(謝季佳)", 
" Zhao AG(趙愛國)", " Hong YS(洪友士)", "Wu XD(武曉東)", " Ge F(葛斐)", 
" Hong YS(洪友士)")), row.names = c(NA, -32L), class = "data.frame", .Names = c("title", 
"publish", "author")) 

我關注的是「作者」一欄：

1. 所有作者用分號分開的（「;」）
2. 不是所有的論文都有相同數量的作者。

現在，我想分離「作者」列到各個欄目中，以便通過igraph繪製合着者圖。看來「tidyr」的最佳選擇，但它不能正常工作：

> library(tidyr) 
> v_t <- separate(itemlist, col="author", sep = ";", remove = TRUE, convert = FALSE) 
Error in simplifyPieces(pieces, n, fill == "left") : 
    argument "into" is missing, with no default 

我不明白的錯誤信息恰恰意味着。我們需要滿足什麼條件才能將「作者」分成許多列。我認爲，由於tidyr提供了分隔行或列的功能，它必須是分離使用這些表的方法。我們應該意識到嗎？

Answer 1

單獨需要函數中的參數into。這些應該是要創建的變量的名稱。你的電話確實不包括論據。

的改編幫助文件例如：

library(dplyr) 
library(tidyr) 
df <- data.frame(x = c(NA, "a.b", "a.d", "b.c")) 
separate(data = df, col = x, into = c("A", "B")) 
    A B 
1 <NA> <NA> 
2 a b 
3 a d 
4 b c 

您可以使用str_count()從stringr以確定您的作家列作者的最大數量，然後用它來指定列數的創建separate()功能。 我用這種問答&一個作爲啓示：Separate a String using Tidyr's "separate" into Multiple Columns and then Create a New Column with Counts

下面是從一個簡化的數據集的示例：

df <- data.frame(id = c(1,2,3), 
      author = c("name1; name2; name3", 
         "name1; name2", "name1")) 

df 
    id    author 
1 1 name1; name2; name3 
2 2  name1; name2 
3 3    name1 
library(tidyr) 
library(stringr) 
str_count(df$author, ";") 
[1] 2 1 0 
max_n_authors <- max(str_count(df$author, ";")) + 1 
max_n_authors 
[1] 3 
paste("author", 1:max_n_authors) 
[1] "author 1" "author 2" "author 3" 
df <- df %>% 
    separate(., col = author, into = paste("author", 1:max_n_authors)) 
Warning message: 
Too few values at 2 locations: 2, 3 
df 
    id author 1 author 2 author 3 
1 1 name1 name2 name3 
2 2 name1 name2  <NA> 
3 3 name1  <NA>  <NA>