“'到'缺少'在单独的列（tidyr）

Question

我构建了10篇论文的元数据。该dput()结果介绍如下：

> dput(itemlist) 
structure(list(title = c("钱学森工程科学思想的实践者 [科普文章]", 
"超高周疲劳裂纹萌生与初始扩展的特征尺度 [科普文章]", "Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊论文]", 
"一种热机械疲劳实验的装置和方法 [专利]", "IUTAM和ICTAM的起源和历程 [科普文章]", 
"加载频率对金属材料超高周疲劳性能的影响 [会议论文]", "金属材料超高周疲劳行为的Monte-Carlo模拟 [会议论文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [会议论文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [会议论文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [会议论文]" 
), publish = c("2014", "2014", " 2013", "专利类型: 发明专利, 专利号: ZL2009102374751, 申请日期: 2012, 公开日期: 2012-12-27", 
"2012", "第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", 
"第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", "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; 中国科学院老科技工作者协会工程力学分会", 
"Sih G C; Hong YS(洪友士)", "谢季佳; 赵爱国; 武晓东; 洪友士", 
"陈杰; 刘洋; 汤亚南; 洪友士", "赵爱国; 洪友士; 谢季佳", "雷铮强; 洪友士; 谢季佳; 赵爱国", 
"Zhang SY(张双寅); Wang L(王雷); Hong YS(洪友士)", "Lei ZQ(雷铮强); Xie JJ(谢季佳); Zhao AG(赵爱国); Hong YS(洪友士)", 
"Wu XD(武晓东); Ge F(葛斐); Hong YS(洪友士)")), .Names = c("title", 
"publish", "author"), row.names = c(NA, 10L), class = "data.frame") 

我发现tidyr可以通过每个元素的一个属性单独的列表。在这个例子中，我“作者”分成不同的行：

> dput(itemlist_tidy) 
structure(list(title = c("钱学森工程科学思想的实践者 [科普文章]", 
"钱学森工程科学思想的实践者 [科普文章]", "钱学森工程科学思想的实践者 [科普文章]", 
"超高周疲劳裂纹萌生与初始扩展的特征尺度 [科普文章]", "超高周疲劳裂纹萌生与初始扩展的特征尺度 [科普文章]", 
"Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊论文]", 
"Proceedings of International conference on Airworthiness & Fatigue – 7th ICSAELS Series Conference [期刊论文]", 
"一种热机械疲劳实验的装置和方法 [专利]", "一种热机械疲劳实验的装置和方法 [专利]", 
"一种热机械疲劳实验的装置和方法 [专利]", "一种热机械疲劳实验的装置和方法 [专利]", 
"IUTAM和ICTAM的起源和历程 [科普文章]", "IUTAM和ICTAM的起源和历程 [科普文章]", 
"IUTAM和ICTAM的起源和历程 [科普文章]", "IUTAM和ICTAM的起源和历程 [科普文章]", 
"加载频率对金属材料超高周疲劳性能的影响 [会议论文]", "加载频率对金属材料超高周疲劳性能的影响 [会议论文]", 
"加载频率对金属材料超高周疲劳性能的影响 [会议论文]", "金属材料超高周疲劳行为的Monte-Carlo模拟 [会议论文]", 
"金属材料超高周疲劳行为的Monte-Carlo模拟 [会议论文]", "金属材料超高周疲劳行为的Monte-Carlo模拟 [会议论文]", 
"金属材料超高周疲劳行为的Monte-Carlo模拟 [会议论文]", "Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [会议论文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [会议论文]", 
"Vibration behavior and response to an accidental collision of SFT prototype in Qiandao Lake (China) [会议论文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [会议论文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [会议论文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [会议论文]", 
"A simulation on microstructure sensitivity to very-high-cycle fatigue behavior of metallic materials [会议论文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [会议论文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [会议论文]", 
"Effect of traveling wave on vortex-induced vibrations of submerged floating tunnel tethers [会议论文]" 
), publish = c("2014", "2014", "2014", "2014", "2014", " 2013", 
" 2013", "专利类型: 发明专利, 专利号: ZL2009102374751, 申请日期: 2012, 公开日期: 2012-12-27", 
"专利类型: 发明专利, 专利号: ZL2009102374751, 申请日期: 2012, 公开日期: 2012-12-27", 
"专利类型: 发明专利, 专利号: ZL2009102374751, 申请日期: 2012, 公开日期: 2012-12-27", 
"专利类型: 发明专利, 专利号: ZL2009102374751, 申请日期: 2012, 公开日期: 2012-12-27", 
"2012", "2012", "2012", "2012", "第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", 
"第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", "第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", 
"第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", "第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", 
"第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", "第十五届全国疲劳与断裂学术会议摘要及论文集, 中国广东佛山", 
"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", " 中国科学院老科技工作者协会工程力学分会", 
"Sih G C", " Hong YS(洪友士)", "谢季佳", " 赵爱国", " 武晓东", 
" 洪友士", "陈杰", " 刘洋", " 汤亚南", " 洪友士", "赵爱国", " 洪友士", 
" 谢季佳", "雷铮强", " 洪友士", " 谢季佳", " 赵爱国", "Zhang SY(张双寅)", 
" Wang L(王雷)", " Hong YS(洪友士)", "Lei ZQ(雷铮强)", " Xie JJ(谢季佳)", 
" Zhao AG(赵爱国)", " Hong YS(洪友士)", "Wu XD(武晓东)", " Ge F(葛斐)", 
" Hong YS(洪友士)")), row.names = c(NA, -32L), class = "data.frame", .Names = c("title", 
"publish", "author")) 

我关注的是“作者”一栏：

1. 所有作者用分号分开的（“;”）
2. 不是所有的论文都有相同数量的作者。

现在，我想分离“作者”列到各个栏目中，以便通过igraph绘制合着者图。看来“tidyr”的最佳选择，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 

我不明白的错误信息恰恰意味着。我们需要满足什么条件才能将“作者”分成许多列。我认为，由于tidyr提供了分隔行或列的功能，它必须是分离使用这些表的方法。我们应该意识到吗？

Answer 1

单独需要函数中的参数into。这些应该是要创建的变量的名称。你的电话确实不包括论据。

的改编帮助文件例如：

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()从stringr以确定您的作家列作者的最大数量，然后用它来指定列数的创建separate()功能。 我用这种问答&一个作为启示：Separate a String using Tidyr's "separate" into Multiple Columns and then Create a New Column with Counts

下面是从一个简化的数据集的示例：

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>