Nominal to Date

felix_w

Dear Rapidminer Community

 

I am struggling again with some Nominal to Date conversions and I hope you can help me. I am extracting with an "extract macro" a date value and I am getting a nominal value. Now I want to convert this nominal value from the macro again back to a date value.

 

The nominal format is:

May 22, 2016

 

How can I convert this into date format? All I get is: "Cannot parse date" and I have tried already plenty of options.

 

Any help would be greatly appreciated!

 

Best regards

Felix

yyhuang

Hi @felix_w,

 

You may have at least 2 ways to convert nominal string to a date by a customized date format.

 

My example process attached here. Be careful that no quotes on the date string of the macro variable.

 

<?xml version="1.0" encoding="UTF-8"?><process version="8.1.001">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="8.1.001" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="set_macro" compatibility="8.1.001" expanded="true" height="68" name="Set Macro" width="90" x="380" y="34">
        <parameter key="macro" value="someDate"/>
        <parameter key="value" value="May 22, 2016"/>
      </operator>
      <operator activated="true" class="generate_macro" compatibility="8.1.001" expanded="true" height="68" name="Generate Macro, method2" width="90" x="514" y="136">
        <list key="function_descriptions">
          <parameter key="nominalDate" value="date_parse_custom(%{someDate},&quot;MMM dd, yyyy&quot;,&quot;en&quot;)"/>
        </list>
      </operator>
      <operator activated="true" breakpoints="after" class="generate_data_user_specification" compatibility="8.1.001" expanded="true" height="68" name="Generate Data by User Specification" width="90" x="514" y="34">
        <list key="attribute_values">
          <parameter key="someDate" value="%{someDate}"/>
        </list>
        <list key="set_additional_roles"/>
      </operator>
      <operator activated="true" class="nominal_to_date" compatibility="8.1.001" expanded="true" height="82" name="Nominal2Date, method1" width="90" x="648" y="34">
        <parameter key="attribute_name" value="someDate"/>
        <parameter key="date_format" value="MMM dd, yyyy"/>
        <parameter key="keep_old_attribute" value="true"/>
      </operator>
      <connect from_op="Generate Data by User Specification" from_port="output" to_op="Nominal2Date, method1" to_port="example set input"/>
      <connect from_op="Nominal2Date, method1" 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>

YY

felix_w

@: yyhuang thank you so much!! Now it finally works!  

 

I still have one question though: Why does "MMM dd, yyyy" work for a date like this: "May 22, 2016"? I don't understand why those 3 "MMM" work, I thought for a month I would always write a double M ("MM").. which was also my mistake because I tried many variances of "MM dd,yyyy and nothing worked. 

 

Felix

yyhuang

Hi @felix_w,

 

Hope these links could help you understand better about the date formats.

 

https://help.gooddata.com/cloudconnect/manual/date-and-time-format.html

https://www.vsni.co.uk/software/genstat/htmlhelp/spread/DateFormats.htm

 

 

Inside rapidminer, you can also have a quick reference list from "nominal to date" operator.

 

Some standard date formats are listed there

 

 

Cheers,

YY

felix_w

That's really helpful! Now I get, it's simply because my date (May) has 3 letters, that is why I need three M's (MMM), right?! Would have been quite streight forward..