read.table() 错误，即使所有元素都存在

Question

我收到 read.table() 错误:

data <- read.table(file, header=T, stringsAsFactors=F, sep="@")
Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,  : 
  line 160 did not have 28 elements

我检查了第 160 行，它确实有 28 个元素(它有 27 个 @ 符号)。
我检查了所有 30242 行，有 816534 个 @ 符号，每行 27 个，所以我很确定每一行都有 28 个元素。我还检查了文件以确认除了作为分隔符之外的任何地方都没有 @ 符号。
有谁知道这里发生了什么？
编辑:文件的第 160 行

158@Mental state: 1. Overall clinical symptoms@MD@S@2002@CMP-005@02@20.67@23.58@Clozapine versus typical neuroleptic medication for schizophrenia@IV@4.47@02@SENSITIVITY ANALYSIS - CHINESE TRIALS@CD000059@6.94@Fixed@16@5@2@45@Chinese trials@YES@Xia 2002 (CPZ)@STD-Xia-2002-_x0028_CPZ_x0029_@579@566@40

edit2:文件的第 161 行

159@Length of surgery (minutes)@MD@Y@1995@CMP-001@01@59.0@47.0@Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults@IV@23.9@01@Summary: Femoral nail (all types) versus sliding hip screw (SHS)@CD000093@13.3@Random@12@1@1@53@Gamma nail@YES@O'Brien 1995@STD-O_x0027_Brien-1995@958@941@49

Answer 1

我认为问题在于有一个换行符需要被 quote 参数识别。我们来看一下。

txt <- c(
    "158@Mental state: 1. Overall clinical symptoms@MD@S@2002@CMP-005@02@20.67@23.58@Clozapine versus typical neuroleptic medication for schizophrenia@IV@4.47@02@SENSITIVITY ANALYSIS - CHINESE TRIALS@CD000059@6.94@Fixed@16@5@2@45@Chinese trials@YES@Xia 2002 (CPZ)@STD-Xia-2002-_x0028_CPZ_x0029_@579@566@40", 
    "159@Length of surgery (minutes)@MD@Y@1995@CMP-001@01@59.0@47.0@Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults@IV@23.9@01@Summary: Femoral nail (all types) versus sliding hip screw (SHS)@CD000093@13.3@Random@12@1@1@53@Gamma nail@YES@O'Brien 1995@STD-O_x0027_Brien-1995@958@941@49"
)

我们可以使用 count.fields() 来预览文件中的字段长度。使用正常的 sep = "@" 而没有其他内容，我们会在两行之间得到 NA，并且计数不正确

count.fields(textConnection(txt), sep = "@")
# [1] 28 NA 24

但是当我们在 quote 中识别出换行符时，它会返回正确的长度

count.fields(textConnection(txt), sep = "@", quote = "\n")
# [1] 28 28 

因此，我建议您将 quote = "\n" 添加到您的 read.table 调用中，看看是否能解决问题。它对我有用

read.table(text = txt, sep = "@")
# [1] V1  V2  V3  V4  V5  V6  V7  V8  V9  V10 V11 V12 V13 V14 V15 V16 V17 V18 V19 V20 V21 V22 V23 V24 V25 V26 V27 V28
# <0 rows> (or 0-length row.names)

df <- read.table(text = txt, sep = "@", quote = "\n")
dim(df)
# [1]  2 28
anyNA(df)
# [1] FALSE