对不起，我是RapidMiner的新手，只做了基础教程。
我有一个像
这样的数据集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列的最高值（例如Value1）并使用它进行进一步计算（生成属性）。
谢谢。
答案 0 :(得分：3)
有很多方法可以实现。以下是使用Aggregate运算符查找最大值的Join将其与原始值Generate Attributes连接以进行计算。
<?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>
答案 1 :(得分：0)
另一种方法是将Extract Macro运算符与statistics设置max一起使用。这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。
优点是您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：由于宏值存储为文本，因此首先必须parse使用它们的数值。
答案 2 :(得分：0)
第三个选项是Sort示例集，只保留带有Filter Example Range运算符的最大值的示例。如果您对其他属性的值感兴趣，当某个属性最大时，这会派上用场。
<?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>