将数据从xml转换为R数据帧

Question

我正在尝试将xml文件转换为数据帧,但格式似乎已关闭.我已经看了不同的教程,虽然我已经成功获得了我需要的信息,使用for循环并导航解析后的文件,但我被告知这个解决方案效率不高.

我试过这段代码:

require(XML)
parsed<-xmlParse("SEWL.xml")
xmlToDataFrame(parsed)

但它给出了一个错误:错误[<-.data.frame(*tmp*,I,名称(节点[[I]]),值= C( "\" LL18179\"\" 2016/08\"0.32485.43896.59801.2131 \" OK\"" ,:列的重复下标

这个其他代码有效,但格式不是我需要的:

require(XML)
require(plyr)
pldf<-ldply(xmlToList("SEWL.xml"),data.frame)

结果数据框如下:

          .id              X..i.. text  .attrs test.code test.validuntil test.meas.text test.meas..attrs test.meas.text.1
1  technician              "John" <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
2    location                "CO" <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
3        temp                <NA> 21.3 celsius      <NA>            <NA>           <NA>             <NA>             <NA>
4     runtype           "routine" <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
5      sample                <NA> <NA>    2323 "LL18179"       "2016/08"         0.3248         baseline           5.4389
6      sample                <NA> <NA>    2323 "LL18179"       "2016/08"         0.3248         baseline           5.4389
7      sample                <NA> <NA> 8979237 "AA09453"       "2016/03"         0.0117         baseline           5.6012
8      sample                <NA> <NA> 8979237 "AA09453"       "2016/03"         0.0117         baseline           5.6012
9      .attrs 2015_07_31_11_33_22 <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
10     .attrs            20150731 <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
11     .attrs              113322 <NA>    <NA>      <NA>            <NA>           <NA>             <NA>             <NA>
   test.meas..attrs.1 test.meas.text.2 test.meas..attrs.2 test.calc test.result test..attrs test.code.1 test.validuntil.1
1                <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
2                <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
3                <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
4                <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
5                 std           6.5980               data    1.2131        "OK"      laslum "ATR150607"         "2017/05"
6                 std           6.5980               data    1.2131        "OK"           3 "ATR150607"         "2017/05"
7                 std           1.1431               data    0.2041      "FAIL"       absat        <NA>              <NA>
8                 std           1.1431               data    0.2041      "FAIL"           2        <NA>              <NA>
9                <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
10               <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
11               <NA>             <NA>               <NA>      <NA>        <NA>        <NA>        <NA>              <NA>
   test.meas.text.3 test.meas..attrs.3 test.meas.text.4 test.meas..attrs.4 test.meas.text.5 test.meas..attrs.5
1              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
2              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
3              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
4              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
5            0.0673           baseline           4.9721                std          10.3851               data
6            0.0673           baseline           4.9721                std          10.3851               data
7              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
8              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
9              <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
10             <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
11             <NA>               <NA>             <NA>               <NA>             <NA>               <NA>
   test.calc.1 test.result.1 test..attrs.1
1         <NA>          <NA>          <NA>
2         <NA>          <NA>          <NA>
3         <NA>          <NA>          <NA>
4         <NA>          <NA>          <NA>
5       2.0886     "Warning"           atr
6       2.0886     "Warning"             1
7         <NA>          <NA>          <NA>
8         <NA>          <NA>          <NA>
9         <NA>          <NA>          <NA>
10        <NA>          <NA>          <NA>
11        <NA>          <NA>          <NA>

这是我正在使用的示例XML文件:

<?xml version="1.0" encoding="UTF-8"?>
<experiment name="abc123" date="20150731" time="113322">
    <technician>"John"</technician>
    <location>"CO"</location>
    <temp scale="celsius">21.3</temp>
    <runtype>"routine"</runtype>
    <sample id="2323">
        <test name="laslum" order="3">
            <code>"LL18179"</code>
            <validuntil>"2016/08"</validuntil>
            <meas name="baseline">0.3248</meas>
            <meas name="std">5.4389</meas>
            <meas name="data">6.5980</meas>
            <calc>1.2131</calc>
            <result>"OK"</result>
        </test>
        <test name="atr" order="1">
            <code>"ATR150607"</code>
            <validuntil>"2017/05"</validuntil>
            <meas name="baseline">0.0673</meas>
            <meas name="std">4.9721</meas>
            <meas name="data">10.3851</meas>
            <calc>2.0886</calc>
            <result>"Warning"</result>
        </test>
    </sample>
    <sample id="8979237">
        <test name="absat" order="2">
            <code>"AA09453"</code>
            <validuntil>"2016/03"</validuntil>
            <meas name="baseline">0.0117</meas>
            <meas name="std">5.6012</meas>
            <meas name="data">1.1431</meas>
            <calc>0.2041</calc>
            <result>"FAIL"</result>
        </test>
    </sample>
</experiment>

我希望获得的数据框:

  experiment technician location temp runtype  sample   test order      code validuntil baseline    std    data   calc  result     date   time
1     abc123       John       CO 21.3 routine    2323 laslum     3   LL18179    2016/08   0.3248 5.4389  6.5980 1.2131      OK 20150731 113322
2     abc123       John       CO 21.3 routine    2323    atr     1 ATR150607    2017/05   0.0673 4.9721 10.3851 2.0886 Warning 20150731 113322
3     abc123       John       CO 21.3 routine 8979237  absat     2   AA09453    2016/03   0.0117 5.6012  1.1431 0.2041    FAIL 20150731 113322

我不需要完全相同的格式,只需要足够接近的东西,以便将其转换为示例.

Answer 1

我们提供了两种解析XML的方法.第一个(对实验/样本/测试执行三次迭代)可能会运行得更快,但第二个(在测试节点上使用单个循环并在每个测试节点上通过树返回以获取其祖先)具有更简单的代码.

1)使用Lines在端部在注我们实现三重xpathApply/xpathSApply迭代过实验/样品/测试节点.e,s并分别t表示当前的这样的节点.

library(XML)
doc <- xmlTreeParse(Lines, asText = TRUE, useInternalNodes = TRUE)

do.call("rbind", xpathApply(doc, "//experiment", function(e) {
  data.frame(experiment = xmlAttrs(e)[["name"]],
       technician = xmlValue(e[["technician"]]),
       location = xmlValue(e[["location"]]),
       temp = xmlValue(e[["temp"]]),
       runtype = xmlValue(e[["runtype"]]),
       t(do.call(cbind, xpathApply(e, "sample", function(s) {
            sample <- xmlAttrs(s)[["id"]]
            xpathSApply(s, "test", function(t) {
                   c(sample = sample,
                        test = xmlAttrs(t)[["name"]],
                        order = xmlAttrs(t)[["order"]],
                        code = xmlValue(t[["code"]]),
                        validuntil = xmlValue(t[["validuntil"]]),
                        baseline = xmlValue(t["meas"][[1]]),
                        std = xmlValue(t["meas"][[2]]),
                        data = xmlValue(t["meas"][[3]]),
                        calc = xmlValue(t[["calc"]]),
                        result = xmlValue(t[["result"]])
             )})}))),
       date = xmlAttrs(e)[["date"]],
       time = xmlAttrs(e)[["time"]]
)}))

赠送:

  experiment technician location temp   runtype  sample   test order
1     abc123     "John"     "CO" 21.3 "routine"    2323 laslum     3
2     abc123     "John"     "CO" 21.3 "routine"    2323    atr     1
3     abc123     "John"     "CO" 21.3 "routine" 8979237  absat     2
         code validuntil baseline    std    data   calc    result     date
1   "LL18179"  "2016/08"   0.3248 5.4389  6.5980 1.2131      "OK" 20150731
2 "ATR150607"  "2017/05"   0.0673 4.9721 10.3851 2.0886 "Warning" 20150731
3   "AA09453"  "2016/03"   0.0117 5.6012  1.1431 0.2041    "FAIL" 20150731
    time
1 113322
2 113322
3 113322

2)这是一种替代方法,我们只在测试节点上循环,然后向上到父母和祖父母,以获得相应的样本和经验信息.

library(XML)
doc <- xmlTreeParse(Lines, asText = TRUE, useInternalNodes = TRUE)

do.call("rbind", xpathApply(doc, "//test", function(t) { # t is test node
        s <- xmlParent(t) # s is sample node
        e <- xmlParent(s) # e is experiment node
        data.frame(experiment = xmlAttrs(e)[["name"]],
          technician = xmlValue(e[["technician"]]),
          location = xmlValue(e[["location"]]),
          temp = xmlValue(e[["temp"]]),
          runtype = xmlValue(e[["runtype"]]),
          sample = xmlAttrs(s)[["id"]],
          test = xmlAttrs(t)[["name"]],
          order = xmlAttrs(t)[["order"]],
          code = xmlValue(t[["code"]]),
          validuntil = xmlValue(t[["validuntil"]]),
          baseline = xmlValue(t["meas"][[1]]),
          std = xmlValue(t["meas"][[2]]),
          data = xmlValue(t["meas"][[3]]),
          calc = xmlValue(t[["calc"]]),
          result = xmlValue(t[["result"]]),
          date = xmlAttrs(e)[["date"]],
          time = xmlAttrs(e)[["time"]]
       )
}))

赠送:

  experiment technician location temp   runtype  sample   test order
1     abc123     "John"     "CO" 21.3 "routine"    2323 laslum     3
2     abc123     "John"     "CO" 21.3 "routine"    2323    atr     1
3     abc123     "John"     "CO" 21.3 "routine" 8979237  absat     2
         code validuntil baseline    std    data   calc    result     date
1   "LL18179"  "2016/08"   0.3248 5.4389  6.5980 1.2131      "OK" 20150731
2 "ATR150607"  "2017/05"   0.0673 4.9721 10.3851 2.0886 "Warning" 20150731
3   "AA09453"  "2016/03"   0.0117 5.6012  1.1431 0.2041    "FAIL" 20150731
    time
1 113322
2 113322
3 113322

注1:

另外,如果您将输入XML文件SEWL.xml读入Excel,它将合理地将其放入表格格式中,尽管需要进一步处理才能将其精确地放入问题中的表单中.

笔记2:

Lines作为R对象的输入是:

Lines <- '<?xml version="1.0" encoding="UTF-8"?>
<experiment name="abc123" date="20150731" time="113322">
    <technician>"John"</technician>
    <location>"CO"</location>
    <temp scale="celsius">21.3</temp>
    <runtype>"routine"</runtype>
    <sample id="2323">
        <test name="laslum" order="3">
            <code>"LL18179"</code>
            <validuntil>"2016/08"</validuntil>
            <meas name="baseline">0.3248</meas>
            <meas name="std">5.4389</meas>
            <meas name="data">6.5980</meas>
            <calc>1.2131</calc>
            <result>"OK"</result>
        </test>
        <test name="atr" order="1">
            <code>"ATR150607"</code>
            <validuntil>"2017/05"</validuntil>
            <meas name="baseline">0.0673</meas>
            <meas name="std">4.9721</meas>
            <meas name="data">10.3851</meas>
            <calc>2.0886</calc>
            <result>"Warning"</result>
        </test>
    </sample>
    <sample id="8979237">
        <test name="absat" order="2">
            <code>"AA09453"</code>
            <validuntil>"2016/03"</validuntil>
            <meas name="baseline">0.0117</meas>
            <meas name="std">5.6012</meas>
            <meas name="data">1.1431</meas>
            <calc>0.2041</calc>
            <result>"FAIL"</result>
        </test>
    </sample>
</experiment>'