if-function, comparing dates

felix_w

Dear Rapidminer Community, 

 

I have a problem I am pretty sure you can help me with.  

 

I have a range of dates which are listed below each other like this: 

01.04.2015

02.04.2015

....

31.12.2017

 

What I would like to do is to implement a seperate Attribute which sets a mark if the date is before a certain date. This means, set "1" if date is before 01.08.2016 and after 01.08.2016 set 2. 

 

The date format I use in Rapidminer is: e.g. "Apr 1, 2015 12:00AM"

 

I tried to do this via "Generate Attributes" and implement an if-function. Like: if(date < 01.08.2017, 1,2) but it didnt work. Is there any handy possibility to do this? 

 

Best regards

Felix

Edin_Klapic

Hi @felix_w,

 

In your special case you might also consider the function expression date_before().

The expression would then be:

 

if(date_before(Datum,date_parse_custom("01.08.2016","dd.MM.yyyy")),1,2)

 

Process is attached.

 

Best regards,

Edin

 

<?xml version="1.0" encoding="UTF-8"?><process version="8.0.001">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="8.0.001" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="retrieve" compatibility="8.0.001" expanded="true" height="68" name="Retrieve Datum" width="90" x="45" y="34">
        <parameter key="repository_entry" value="//Local Repository/Community/date problem/Datum"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="8.0.001" expanded="true" height="82" name="Generate Attributes" width="90" x="179" y="34">
        <list key="function_descriptions">
          <parameter key="before my date" value="if(date_before(Datum,date_parse_custom(&quot;01.08.2016&quot;,&quot;dd.MM.yyyy&quot;)),1,2)"/>
        </list>
      </operator>
      <connect from_op="Retrieve Datum" from_port="output" 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>

MartinLiebig

Hi,

 

i am a fan of using date_diff even though i often mess up a minus sign. So my way would be:

 

if(
	date_diff(date_parse_custom("01-01-2017","dd-MM-YYYY"), date) > 1,
	"date is bigger",
	"date is smaller"
)

Best,

Martin

felix_w

Hi Martin, 

 

first of all thank you for help!

 

I have one further question. The if-function you sent me works for the day 01.01.2017 but when I am adapting the date to e.g 01.04.2017 it still sets the markers only before and after the 01.01.2017? Furthermore, I don't really understand what the "< 1" does in the function? 

 

Best regards

Felix

MartinLiebig

Hi,

 

date_diff returns the number of milliseconds between the two dates which are delivered. If this is > 1 then the first date was bigger than the second (or the other way around?).

Thus you can easily do 01-04-2017 or what ever you prefer. You can also change the format, since i used the custom date format option.

Note: date is the attribute i am comparing this to

 

Best,

Martin

felix_w

Hi Martin, 

 

I am sorry I have adapted the function but it still does not work on my data? It still sets marks until 01.01.2017 and then changes although I have changed the date in the function to 01.04.2017? 

 

Yes, I have set date to my "Datum"

 

 

 

MartinLiebig

Hey,

 

can you maybe post an example process? Hard to debug without

 

Best,

Martin

felix_w

Hi Martin, 

 

I can't send you the original process because it contains sensitive material but I simply copied the "Datum" column in a seperate excel and the only thing to do would be to load it and then use generate attribute. 

Thank you a lot for helping me out!! 

 

Regards

Felix

 

felix_w

YESS it worked

 

Although I have no idea why my own solution didn't work because I think I tried this before but nevermind I am just happy that it works now ! 

 

Also thank you again Martin for your help! 

 

Best regards

Felix

Edin_Klapic

Date functions are always tricky

Luckily, the explanations in the function expressions are quite helpful in those cases.

 

Best,

Edin