Question

我尝试使用以下代码将http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data中的数据加载到R中

hData <- read.table(file.choose(), sep = "\t", dec = ",", fileEncoding = "UTF-16")

但它没有填充确切的数据。数据中包含76个属性，详细信息请参见：http://archive.ics.uci.edu/ml/datasets/Heart+Disease。

有人能告诉我我做错了什么吗？

Answer 1

该文件包含导致问题的额外换行符。如果你用正则表达式将它们删除，你可以阅读：

# read file into a single string
x <- readr::read_file('http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data')

# or in base, x <- paste(readLines(url('http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data')), collapse = '\n')

# gsub out line breaks that follow numbers (not "name") and read data
df <- read.table(text = gsub('(\\d)\\n', '\\1 ', x))

head(df, 2)
##     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
## 1 1254  0 40  1  1  0  0 -9  2 140   0 289  -9  -9  -9   0  -9  -9   0  12  16  84   0   0   0
## 2 1255  0 49  0  1  0  0 -9  3 160   1 180  -9  -9  -9   0  -9  -9   0  11  16  84   0   0   0
##   V26 V27 V28 V29 V30 V31 V32 V33 V34 V35 V36 V37 V38 V39 V40 V41 V42 V43 V44 V45 V46 V47 V48
## 1   0   0 150  18  -9   7 172  86 200 110 140  86   0   0   0  -9  26  20  -9  -9  -9  -9  -9
## 2   0   0  -9  10   9   7 156 100 220 106 160  90   0   0   1   2  14  13  -9  -9  -9  -9  -9
##   V49 V50 V51 V52 V53 V54 V55 V56 V57 V58 V59 V60 V61 V62 V63 V64 V65 V66 V67 V68 V69 V70 V71
## 1  -9  -9  -9  -9  -9  -9  12  20  84   0  -9  -9  -9  -9  -9  -9  -9  -9  -9  -9   1   1   1
## 2  -9  -9  -9  -9  -9  -9  11  20  84   1  -9  -9   2  -9  -9  -9  -9  -9  -9  -9   1   1   1
##   V72 V73 V74 V75  V76
## 1   1   1  -9  -9 name
## 2   1   1  -9  -9 name

如果最后没有恰好是不同的数据类型，您可以使用scan制作一个向量，然后split并重新组合：

# download data and split into a character vector
x <- scan(url('http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data'), character())

# split and assemble data.frame
df <- data.frame(split(x, 1:76), stringsAsFactors = FALSE)

# fix types
df[] <- lapply(df, type.convert, as.is = TRUE)

或传递scan一个单行应该直接读入列表的类型的模型：

x <- scan(url('http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data'), 
          c(replicate(75, numeric()), list(character())))

df <- as.data.frame(x)
names(df) <- paste0('V', 1:76)    # replace ugly names

如果确定类型结构的正确性太复杂，请使用replicate(76, character())以字符形式阅读所有内容，并像上一个选项一样使用type.convert。

或者，使用readLines，split为每个分组的行创建一个包含正确字符串的列表，并paste将它们全部重新组合起来以使用read.table：

x <- readLines(url('http://archive.ics.uci.edu/ml/machine-learning-databases/heart-disease/hungarian.data'))

df <- read.table(text = paste(sapply(split(x, 
                                           rep(seq(length(x) / 10), each = 10)), 
                                     paste, collapse = ' '), collapse = '\n'))

如何将.data文件读入R中

1 个答案: