Problem with Nominal to Date

blatoo

Hello RapidMiner Team,

I have a problem with the "Nominal to Date". I don't know, if it is a bugger.

I have a small table, with attribute "time" and "value", "time" is nominal, value is numerical

id     time         value
1 10:00:00 3.0
2 11:00:00 4.0
3 12:00:00 5.0
4 12:30:00 6.0
5 13:00:00 7.0
6 14:00:00 8.0

In my process, I apply the "Nominal to Date" on "time" attribute with the data format: hh:mm:ss, then I plot the result with "Scatter", x-Axis: time, y-Axis: value,
then I notice that, RapidMiner consider 12:00:00 equals 00:00:00, so it is much earlier than 10:00:00 !!! Why???

Thanks very much in advance!

Here is my process:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="6.2.000">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="6.2.000" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="retrieve" compatibility="6.2.000" expanded="true" height="60" name="Retrieve timeTest" width="90" x="179" y="345">
        <parameter key="repository_entry" value="//myLearningRepository/database/timeTest"/>
      </operator>
      <operator activated="true" class="nominal_to_date" compatibility="6.2.000" expanded="true" height="76" name="Nominal to Date" width="90" x="313" y="345">
        <parameter key="attribute_name" value="time"/>
        <parameter key="date_type" value="time"/>
        <parameter key="date_format" value="hh:mm:ss"/>
      </operator>
      <connect from_op="Retrieve timeTest" from_port="output" to_op="Nominal to Date" to_port="example set input"/>
      <connect from_op="Nominal to Date" 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>

Here is my plotted picture

awchisholm

Hello

Try changing the date string to "HH:mm:ss" - the upper case HH signifies 24 hour format

Andrew

blatoo

Hi Andrew,

thanks very much for the tip! It works!!!

by the way, I bought your book "Exploring Data with RapidMiner" from amazon and read it completely in last days, it is so good and practical orientated! Thanks very much!

Conny

awchisholm

Hello Conny

Glad to help ):

Andrew

DocMusher

Hi RM's
I have a similar problem. But my time data ranges from 00:00 to 200:00, which means duration expressed in hours:minutes. The type is guessed as polynomial. how can I change this duration to data I can use for calculation?
Cheers
Sven

awchisholm

Hello

You could use the "Generate Extract" operator like so to convert hours and minutes in the format "hours:minutes" where hours can be greater than 23.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="6.2.000">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="6.2.000" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="generate_data_user_specification" compatibility="6.2.000" expanded="true" height="60" name="Generate Data by User Specification" width="90" x="112" y="75">
        <list key="attribute_values">
          <parameter key="duration" value="&quot;201:21&quot;"/>
        </list>
        <list key="set_additional_roles"/>
      </operator>
      <operator activated="true" class="text:generate_extract" compatibility="6.1.000" expanded="true" height="60" name="Generate Extract" width="90" x="246" y="75">
        <parameter key="source_attribute" value="duration"/>
        <parameter key="query_type" value="Regular Expression"/>
        <list key="string_machting_queries"/>
        <parameter key="attribute_type" value="Numerical"/>
        <list key="regular_expression_queries">
          <parameter key="hours" value="(\d+):.*"/>
          <parameter key="minutes" value="\d+:(\d+)"/>
        </list>
        <list key="regular_region_queries"/>
        <list key="xpath_queries"/>
        <list key="namespaces"/>
        <list key="index_queries"/>
        <list key="jsonpath_queries"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="6.2.000" expanded="true" height="76" name="Generate Attributes" width="90" x="380" y="75">
        <list key="function_descriptions">
          <parameter key="newduration" value="hours*60+minutes"/>
        </list>
      </operator>
      <connect from_op="Generate Data by User Specification" from_port="output" to_op="Generate Extract" to_port="Example Set"/>
      <connect from_op="Generate Extract" 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>

regards

Andrew