快速矿排最大值
快速矿排最大值
提问于 2017-05-15 19:20:18
对不起，我对RapidMiner完全陌生，只做了基础教程。
我有一个数据集
MatchID Value1 Value2 Value3
1 5 1 2
1 4.5 1.5 2
...并且想知道是否有可能获得每个列的最高值(例如Value1)，并使用它进行进一步的计算(生成属性)。
谢谢。
回答 3
Stack Overflow用户
回答已采纳
发布于 2017-05-15 19:45:42
事情发生时有很多种方式。这里有一个使用Aggregate操作符来查找maxima，Join将这个加入到原始，Generate Attributes来做一些计算。
<?xml version="1.0" encoding="UTF-8"?><process version="7.2.003">
<context>
<input/>
<output/>
<macros/>
</context>
<operator activated="true" class="process" compatibility="7.2.003" expanded="true" name="Process">
<process expanded="true">
<operator activated="true" class="retrieve" compatibility="7.2.003" expanded="true" height="68" name="Retrieve Iris" width="90" x="45" y="34">
<parameter key="repository_entry" value="//Samples/data/Iris"/>
</operator>
<operator activated="true" class="aggregate" compatibility="7.2.003" expanded="true" height="82" name="Aggregate" width="90" x="179" y="34">
<parameter key="use_default_aggregation" value="true"/>
<parameter key="default_aggregation_function" value="maximum"/>
<list key="aggregation_attributes"/>
</operator>
<operator activated="true" class="join" compatibility="7.2.003" expanded="true" height="82" name="Join" width="90" x="313" y="34">
<parameter key="join_type" value="outer"/>
<parameter key="use_id_attribute_as_key" value="false"/>
<list key="key_attributes"/>
</operator>
<operator activated="true" class="generate_attributes" compatibility="7.2.003" expanded="true" height="82" name="Generate Attributes" width="90" x="447" y="34">
<list key="function_descriptions">
<parameter key="deltaA1" value="[maximum(a1)]-a1"/>
<parameter key="deltaA2" value="[maximum(a2)]-a2"/>
<parameter key="deltaA3" value="[maximum(a3)]-a3"/>
<parameter key="deltaA4" value="[maximum(a4)]-a4"/>
</list>
</operator>
<connect from_op="Retrieve Iris" from_port="output" to_op="Aggregate" to_port="example set input"/>
<connect from_op="Aggregate" from_port="example set output" to_op="Join" to_port="left"/>
<connect from_op="Aggregate" from_port="original" to_op="Join" to_port="right"/>
<connect from_op="Join" from_port="join" to_op="Generate Attributes" to_port="example set input"/>
<connect from_op="Generate Attributes" from_port="example set output" to_port="result 1"/>
<portSpacing port="source_input 1" spacing="0"/>
<portSpacing port="sink_result 1" spacing="0"/>
<portSpacing port="sink_result 2" spacing="0"/>
</process>
</operator>
</process>Stack Overflow用户
发布于 2017-05-17 10:00:41
另一种方法是使用Extract Macro运算符和statistics设置max。这会将给定属性的最大值存储为宏值，然后可以使用该值，例如在Generate Attributes中。
优点是不需要修改原始数据集，也不必使用join或multiply运算符。
<?xml version="1.0" encoding="UTF-8"?><process version="7.5.000">
<context>
<input/>
<output/>
<macros/>
</context>
<operator activated="true" class="process" compatibility="7.5.000" expanded="true" name="Process">
<process expanded="true">
<operator activated="true" class="retrieve" compatibility="7.5.000" expanded="true" height="68" name="Retrieve Iris" width="90" x="45" y="34">
<parameter key="repository_entry" value="//Samples/data/Iris"/>
</operator>
<operator activated="true" class="extract_macro" compatibility="7.5.000" expanded="true" height="68" name="Extract Macro" width="90" x="179" y="34">
<parameter key="macro" value="maxA1"/>
<parameter key="macro_type" value="statistics"/>
<parameter key="statistics" value="max"/>
<parameter key="attribute_name" value="a1"/>
<list key="additional_macros"/>
<description align="center" color="transparent" colored="false" width="126">extract maximum of attribute a1 and store it in a macro</description>
</operator>
<operator activated="true" class="generate_attributes" compatibility="7.5.000" expanded="true" height="82" name="Generate Attributes" width="90" x="313" y="34">
<list key="function_descriptions">
<parameter key="DifferenceA1" value="parse(%{maxA1})-a1"/>
</list>
<description align="center" color="transparent" colored="false" width="126">calculate the difference of a1 from the maximum using the macro value</description>
</operator>
<connect from_op="Retrieve Iris" from_port="output" to_op="Extract Macro" to_port="example set"/>
<connect from_op="Extract Macro" from_port="example set" to_op="Generate Attributes" to_port="example set input"/>
<connect from_op="Generate Attributes" from_port="example set output" to_port="result 1"/>
<portSpacing port="source_input 1" spacing="0"/>
<portSpacing port="sink_result 1" spacing="0"/>
<portSpacing port="sink_result 2" spacing="0"/>
</process>
</operator>
</process>提示:由于宏值是以文本形式存储的，因此必须首先对它们进行parse，才能使用它们的数值。
Stack Overflow用户
发布于 2017-05-17 10:07:34
第三个选项是Sort示例集，并且只使用Filter Example Range操作符保留该示例的最大值。如果您对其他属性值很感兴趣，那么当某个属性是最大的时，这是有用的。
<?xml version="1.0" encoding="UTF-8"?><process version="7.5.000">
<context>
<input/>
<output/>
<macros/>
</context>
<operator activated="true" class="process" compatibility="7.5.000" expanded="true" name="Process">
<process expanded="true">
<operator activated="true" class="retrieve" compatibility="7.5.000" expanded="true" height="68" name="Retrieve Iris" width="90" x="45" y="34">
<parameter key="repository_entry" value="//Samples/data/Iris"/>
</operator>
<operator activated="true" class="sort" compatibility="7.5.000" expanded="true" height="82" name="Sort" width="90" x="179" y="34">
<parameter key="attribute_name" value="a1"/>
<parameter key="sorting_direction" value="decreasing"/>
<description align="center" color="transparent" colored="false" width="126">sorting the example set on a1 decreasing</description>
</operator>
<operator activated="true" class="filter_example_range" compatibility="7.5.000" expanded="true" height="82" name="Filter Example Range" width="90" x="313" y="34">
<parameter key="first_example" value="1"/>
<parameter key="last_example" value="1"/>
<description align="center" color="transparent" colored="false" width="126">only keeping the first example, which has the maximum for a1</description>
</operator>
<connect from_op="Retrieve Iris" from_port="output" to_op="Sort" to_port="example set input"/>
<connect from_op="Sort" from_port="example set output" to_op="Filter Example Range" to_port="example set input"/>
<connect from_op="Filter Example Range" from_port="example set output" to_port="result 1"/>
<portSpacing port="source_input 1" spacing="0"/>
<portSpacing port="sink_result 1" spacing="0"/>
<portSpacing port="sink_result 2" spacing="0"/>
</process>
</operator>
</process>页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/43987256
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