"R extension - how to get started"

marie

Hey there,

I am really new to the use of RapidMiner and R, and well I did not find anything in the internet on how to get started with the r Extension in RapidMiner that really breaks it down to the basics. So I just tried some very simple things out like the max of a column. 

the script is the following:

rm_main = function(data)
{
max($Temperature)
return(data)
}

and the error message is:

The script yould not be parsed. Please check your R script.

[1] "script.R:5:5: unexpected '$' (....)"

 

Do you know how to solve it?

Or do you have something were one can learn how to get started with the use of the R extension in RapidMiner with just basic knowledge?

Thanks in advance

Marie

 

Ah and here is the xml:

<?xml version="1.0" encoding="UTF-8"?><process version="7.2.001">
 <context>
 <input/>
 <output/>
 <macros/>
 </context>
 <operator activated="true" class="process" compatibility="7.2.001" expanded="true" name="Process">
 <process expanded="true">
 <operator activated="true" class="retrieve" compatibility="7.2.001" expanded="true" height="68" name="Retrieve Golf" width="90" x="45" y="85">
 <parameter key="repository_entry" value="//Samples/data/Golf"/>
 </operator>
 <operator activated="true" class="r_scripting:execute_r" compatibility="7.2.000" expanded="true" height="82" name="Execute R" width="90" x="246" y="85">
 <parameter key="script" value="rm_main = function(data)&#10;{&#10; max($Temperature)&#10;}&#10;"/>
 </operator>
 <connect from_op="Retrieve Golf" from_port="output" to_op="Execute R" to_port="input 1"/>
 <connect from_op="Execute R" from_port="output 1" 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> 

Thomas_Ott

Hi Marie,

 

That means that the resulting R script created an object that RapidMiner can't visualize in the results tab, this is why I added the print statement where you can see the max temp in Log View.  Take a look at the sample tutorial processes loaded for the Execute R operator. Just right click on the operator and click on description. There will be a link for "Jump to Tutorial Processes."

 

There about 4 different R examples which explain a bit on how you can embed your scripts inside RapidMiner. Good luck!

Thomas_Ott

Hi,

 

Working with the Execute R operator is pretty straight forward once you understand how RM is delivering the data to the function.  See your sample script modified.

 

RM is sending it's data to the Execute R script and translates it via the data.tables package. The raw data comes in as "data" via the function(data).  From there I assign it to a golf <- data datafram AND then extract out the column Temperature via output <- max(golf$Temperature)

 

Then I return the output as an object.

 

I added a print statement so you can see the results in your LOG view.

 

<?xml version="1.0" encoding="UTF-8"?><process version="7.2.002">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="7.2.002" expanded="true" name="Process">
    <process expanded="true">
      <operator activated="true" class="retrieve" compatibility="7.2.002" expanded="true" height="68" name="Retrieve Golf" width="90" x="45" y="85">
        <parameter key="repository_entry" value="//Samples/data/Golf"/>
      </operator>
      <operator activated="true" class="r_scripting:execute_r" compatibility="7.2.000" expanded="true" height="82" name="Execute R" width="90" x="179" y="85">
        <parameter key="script" value="rm_main = function(data)&#10;{&#10;golf &lt;- data&#10;&#10;output &lt;- max(golf$Temperature)&#10;&#10;print(str(output))&#10;&#10;return(output)&#10;}&#10;"/>
      </operator>
      <connect from_op="Retrieve Golf" from_port="output" to_op="Execute R" to_port="input 1"/>
      <connect from_op="Execute R" from_port="output 1" 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>

marie

Hey Thomas_Ott,

thank you very much for your quick reply. 

It seems very logical what you write. 

But when I copield the XMl all I get in the Resluts view is:

File

Memory buffered file

 

What does that mean?

With kind regards

Marie