Date_time to be discretized (morning afternoon, evening)

gohel

Hi all,
I want to convert time attribute (of type date time)  into three categories- [morning, afternoon and evening], and I used Discretize by user specification operator for it but it's not helping me out.
For example-
6AM to 11AM- morning
11AM to 4 PM- afternoon
4PM to 10 PM- evening

Can anyone help me out?
Thanks

David_A

Hi @gohel ,

what you need to do is first extract the hours each day. This can be done with the Generate  Attributes operator and the date_get() function.

The Discretize by user specification operator has the drawback, that you can only specify upper limits to your classes, so creating a category "night" that goes from 22PM - 6AM is tricky.

That's why I would again use Generate Attributes and a stacked if-else statement for all cases, see the process xml below for an example.

Best,
David

<?xml version="1.0" encoding="UTF-8"?><process version="9.6.000">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="9.6.000" expanded="true" name="Process">
    <parameter key="logverbosity" value="init"/>
    <parameter key="random_seed" value="2001"/>
    <parameter key="send_mail" value="never"/>
    <parameter key="notification_email" value=""/>
    <parameter key="process_duration_for_mail" value="30"/>
    <parameter key="encoding" value="SYSTEM"/>
    <process expanded="true">
      <operator activated="true" class="utility:create_exampleset" compatibility="9.6.000" expanded="true" height="68" name="Create ExampleSet" width="90" x="179" y="34">
        <parameter key="generator_type" value="date series"/>
        <parameter key="number_of_examples" value="100"/>
        <parameter key="use_stepsize" value="false"/>
        <list key="function_descriptions"/>
        <parameter key="add_id_attribute" value="false"/>
        <list key="numeric_series_configuration"/>
        <list key="date_series_configuration">
          <parameter key="Time" value="2020-04-20 12:00:00.2020-04-30 12:00:00"/>
        </list>
        <list key="date_series_configuration (interval)"/>
        <parameter key="date_format" value="yyyy-MM-dd HH:mm:ss"/>
        <parameter key="time_zone" value="SYSTEM"/>
        <parameter key="column_separator" value=","/>
        <parameter key="parse_all_as_nominal" value="false"/>
        <parameter key="decimal_point_character" value="."/>
        <parameter key="trim_attribute_names" value="true"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="9.6.000" expanded="true" height="82" name="Generate Attributes" width="90" x="447" y="34">
        <list key="function_descriptions">
          <parameter key="extract_hour" value="date_get(Time,DATE_UNIT_HOUR)"/>
          <parameter key="get_day_time" value="if(extract_hour&lt;6,&quot;evening&quot;, if(extract_hour&lt;11,&quot;morning&quot;, if(extract_hour&lt;16,&quot;afternoon&quot;,if(extract_hour&lt;22,&quot;evening&quot;,&quot;morning&quot;))))"/>
          <parameter key="extract_hour_2" value="extract_hour"/>
        </list>
        <parameter key="keep_all" value="true"/>
      </operator>
      <operator activated="true" class="discretize_by_user_specification" compatibility="9.6.000" expanded="true" height="103" name="Discretize" width="90" x="715" y="34">
        <parameter key="return_preprocessing_model" value="false"/>
        <parameter key="create_view" value="false"/>
        <parameter key="attribute_filter_type" value="single"/>
        <parameter key="attribute" value="extract_hour"/>
        <parameter key="attributes" value=""/>
        <parameter key="use_except_expression" value="false"/>
        <parameter key="value_type" value="numeric"/>
        <parameter key="use_value_type_exception" value="false"/>
        <parameter key="except_value_type" value="real"/>
        <parameter key="block_type" value="value_series"/>
        <parameter key="use_block_type_exception" value="false"/>
        <parameter key="except_block_type" value="value_series_end"/>
        <parameter key="invert_selection" value="false"/>
        <parameter key="include_special_attributes" value="false"/>
        <list key="classes">
          <parameter key="night" value="6.0"/>
          <parameter key="morning" value="11.0"/>
          <parameter key="afternoon" value="16.0"/>
          <parameter key="evening" value="22.0"/>
          <parameter key="night" value="24.0"/>
        </list>
      </operator>
      <connect from_op="Create ExampleSet" from_port="output" to_op="Generate Attributes" to_port="example set input"/>
      <connect from_op="Generate Attributes" from_port="example set output" to_op="Discretize" to_port="example set input"/>
      <connect from_op="Discretize" 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>