小编Str*_*d01的帖子

我在这里搜索过,我无法找到如何根据属性过滤xml.我有这个xml:

     <?xml version="1.0" encoding="utf-8"?>
        <document>
            <document_head>
                <title>This is the title</title>
                <version>This is the title</version>
            </document_head>
            <document_body>
                <paragraph id="AXD">
                    <text>
                        This is a text that should be in the result
                    </text>
                    <properties>
                        <size>13px</size>
                        <color>#000000</color>
                    </properties>
                    <author>Current user</author>
                </paragraph>
                <paragraph id="SFI">
                    <properties>
                        <text>
                            This is some other text that should not be in there
                        </text>
                    </properties>
                </paragraph>
                <paragraph id="SFA">
                    <author>Some random guy</author>
                </paragraph>      
                <paragraph id="ARG">
                    This doesn't mean anything.
                </paragraph>
                <paragraph id="RRR">
                    This does, hence should be in there.
                </paragraph>
            </document_body>
        </document> …

我有一个使用XML文件构建的data.frame,现在我想对其值进行计数和求和,比如SQL中的count和sum.

这是data.frame的外观:

   msgDataSource msgFileSource processDate msgNumRows
1        source1       Quarter  2015-01-30         30
2        source1         Month  2015-01-30         15
3        source1         Month  2015-01-30         20
4        source1          Year  2015-01-30          1
5        source2       Quarter  2015-01-30         30
6        source3       Quarter  2015-01-30         15
7        source1          Year  2015-02-01         80
8        source2          Year  2015-02-01         90
9        source1       Quarter  2015-02-01          5
10       source2       Quarter  2015-03-15          9
11       source3       Quarter  2015-03-15         14

这就是我需要的

   processDate msgFileSource msgDataSource sumDataSources   countDataSources
 1:  2015-01-30         Month       source1             35                 2
 2:  2015-01-30       Quarter       source1             30                 1
 3: …