Nominal to Date
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
Best Answer
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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},"MMM dd, yyyy","en")"/>
</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
2
Altair EmployeeAnswers
-
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},"MMM dd, yyyy","en")"/>
</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
2 -
@: 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
0 -
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
2 -
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..
2