Error in Web Crawl: The example set must contain at least one text attribute

turicum

Hi everybody.

in the following, simple, example, where I process a few pages retrieved by a web crawl, I keep seeing the error "The example set must contain at least one text attribute". The "Nominal to Text", which is suggested as a solution this very same problem in other posts, does not remove the error. Interestingly, there seems to be indeed a 'text' attribute  in th example set and the error does not seem to affect the execution of the process. What am I missing?

Thanks!
Marco

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.2.008">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.2.008" expanded="true" name="Process">
    <process expanded="true" height="510" width="909">
      <operator activated="true" class="web:crawl_web" compatibility="5.2.003" expanded="true" height="60" name="Crawl Web" width="90" x="45" y="345">
        <parameter key="url" value="http://www.cnn.com"/>
        <list key="crawling_rules"/>
        <parameter key="write_pages_into_files" value="false"/>
        <parameter key="add_pages_as_attribute" value="true"/>
        <parameter key="max_pages" value="10"/>
        <parameter key="domain" value="server"/>
      </operator>
      <operator activated="true" class="nominal_to_text" compatibility="5.2.008" expanded="true" height="76" name="Nominal to Text" width="90" x="179" y="345"/>
      <operator activated="true" class="multiply" compatibility="5.2.008" expanded="true" height="94" name="Multiply" width="90" x="380" y="345"/>
      <operator activated="true" class="text:process_document_from_data" compatibility="5.2.004" expanded="true" height="76" name="Process Documents from Data" width="90" x="514" y="255">
        <parameter key="vector_creation" value="Term Occurrences"/>
        <list key="specify_weights"/>
        <process expanded="true" height="510" width="909">
          <operator activated="true" class="text:tokenize" compatibility="5.2.004" expanded="true" height="60" name="Tokenize (2)" width="90" x="246" y="30"/>
          <operator activated="true" class="text:generate_n_grams_terms" compatibility="5.2.004" expanded="true" height="60" name="Generate n-Grams (2)" width="90" x="447" y="30"/>
          <connect from_port="document" to_op="Tokenize (2)" to_port="document"/>
          <connect from_op="Tokenize (2)" from_port="document" to_op="Generate n-Grams (2)" to_port="document"/>
          <connect from_op="Generate n-Grams (2)" from_port="document" to_port="document 1"/>
          <portSpacing port="source_document" spacing="0"/>
          <portSpacing port="sink_document 1" spacing="0"/>
          <portSpacing port="sink_document 2" spacing="0"/>
        </process>
      </operator>
      <connect from_op="Crawl Web" from_port="Example Set" to_op="Nominal to Text" to_port="example set input"/>
      <connect from_op="Nominal to Text" from_port="example set output" to_op="Multiply" to_port="input"/>
      <connect from_op="Multiply" from_port="output 1" to_op="Process Documents from Data" to_port="example set"/>
      <connect from_op="Multiply" from_port="output 2" to_port="result 2"/>
      <connect from_op="Process Documents from Data" from_port="example set" 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"/>
      <portSpacing port="sink_result 3" spacing="0"/>
    </process>
  </operator>
</process>
[ /code]

MariusHelf

Hi,

I am not getting any errors on the latest development version. So the error should  be fixed with the next release of RapidMiner and/or the text extension.

All the best,
Marius

turicum

Hi Marius

is the development version available? I couldn't find it on sourceforge.

Thanks

MariusHelf

Hey, what I call development version is pulled and compiled directly from svn. The source code is available on sourceforge, and our website provides a manual on how to compile RapidMiner from source.

Happy compiling!
~Marius