#NULL value is declared as one of the two values of a binominal attribute

agelos_katsanto

Hello everyone,

I import my data and at the "Format your columns" step , on some binominal variables with values 0 or 1 there are missing values. These missing values are parsed as #NULL in this step and the attribute is declared as polynominal . When i try to change the attribute's type back to binominal , #NULL is one of the two values and the 0 or 1 is declared as a missing value noted with "?" .

How i can declare #NULL as missing value in binominal type attribute?

Thank you for your time

 

rfuentealba

Hi @agelos_katsanto

 

Here is a process that does what you want:

 

<?xml version="1.0" encoding="UTF-8"?><process version="9.0.002">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="9.0.002" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="read_csv" compatibility="9.0.002" expanded="true" height="68" name="Read CSV" width="90" x="112" y="34">
        <parameter key="csv_file" value="/Users/master/testing.csv"/>
        <parameter key="column_separators" value=","/>
        <parameter key="skip_comments" value="true"/>
        <parameter key="date_format" value="MMM d, yyyy h:mm:ss a z"/>
        <list key="annotations"/>
        <list key="data_set_meta_data_information">
          <parameter key="0" value="ID.true.integer.attribute"/>
          <parameter key="1" value="State.true.polynominal.attribute"/>
        </list>
        <parameter key="read_not_matching_values_as_missings" value="false"/>
      </operator>
      <operator activated="true" class="replace" compatibility="9.0.002" expanded="true" height="82" name="Replace" width="90" x="246" y="34">
        <parameter key="attribute_filter_type" value="single"/>
        <parameter key="attribute" value="State"/>
        <parameter key="replace_what" value="N"/>
      </operator>
      <operator activated="true" class="nominal_to_binominal" compatibility="9.0.002" expanded="true" height="103" name="Nominal to Binominal" width="90" x="380" y="34">
        <parameter key="attribute_filter_type" value="single"/>
        <parameter key="attribute" value="State"/>
      </operator>
      <connect from_op="Read CSV" from_port="output" to_op="Replace" to_port="example set input"/>
      <connect from_op="Replace" from_port="example set output" to_op="Nominal to Binominal" to_port="example set input"/>
      <connect from_op="Nominal to Binominal" 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>

I basically read the file, assigning it a polynominal value. Replace the N (well, I was lazy) value by nothing, and then apply Nominal to Binominal.

 

You will have to change the route of the csv file attached on the Read CSV operator to make things work for you.

 

Have a good day,

 

agelos_katsanto

Thank you for your time and effort.

My dataset is in *.xls excel file .But this #NULL! value is unparsable from the "Read Excel" operator. 

My problem is that when i import my dataset , the "automated" way of Rapidminer takes some of the initial numerical attributes as polynominal because it cant read #NULL! as missing value. And some of the initial binominal attributes as polynominal for the same reason. When i turn from polynominal to binominal it takes the 0 or 1 value as "?" and not the #NULL.

rfuentealba

Hi @agelos_katsanto

 

What if you export these as text first, what does that appear? If you can send me the file (in a private message), I can get that to work for you and publish an appropriate answer.

 

All the best,

 

Rod.