"Read file depending on Macro-Value"

Hi CrazyT,

yes it is possible to set the filename of any read operator with a macro. But you have to note two things:

1.) The macro operator must be executed before/ the read operator. You can check and change the execution order within the process tab using the button displaying an up-down-arrow with an questionmark.

2.) Metadata handling does not work anymore as the read operator does not know the filename before the process is run.

Best regards,
chero

Thanks for your reply, i was allways wondering, because i thought that you would need to link the macros as input.
(but there is no input for data retrievers of course)
Well I'm kinda new to this program, but i start to like it because its very useful.
But now I'm having another problem, because my filenames aren't just with numbers but with dates.

Is there a way to get the current date within rapidminer(with a macro)?
I looked nearly everywhere but can't find any info about that.

Only thing i found was something about adjusting a date in a column wich can be handy later.
I also found the operator for generating data and for creating a data-column wich i thought could be used to create a column that contains the current date.
Sadly i was wrong .

Btw:
Is there somewhere an overview of the functions you can use in macros?
I found that page http://rapid-i.com/wiki/index.php?title=Generate_Macro , sadly there aren't any date functions.
Are that the only functions that are supported at the moment?


EDIT:
http://rapid-i.com/wiki/index.php?title=First_Steps_With_RapidMiner#Parameter_Macros
Alright, %{t} is what i need i guess.
Sadly it outputs something like this:
2010_06_26-AM_10_16_18
But i need to get a value like:
2010-06-26
Anybody has any idea, how to format the value of a date inside a macro?

Edit again - the solution:
Alright, i solved the last problem myself.
The example below takes the system date and subtracts 2 days from the current date.
To view the content of the macro i added the column as output.(currdate)

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.0">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.0.8" expanded="true" name="Process">
    <process expanded="true" height="476" width="480">
      <operator activated="true" class="generate_data" compatibility="5.0.8" expanded="true" height="60" name="Generate Data (2)" width="90" x="45" y="30">
        <parameter key="number_examples" value="1"/>
        <parameter key="number_of_attributes" value="1"/>
      </operator>
      <operator activated="true" class="set_macro" compatibility="5.0.8" expanded="true" height="76" name="Set Macro (3)" width="90" x="202" y="21">
        <parameter key="macro" value="added_days"/>
        <parameter key="value" value="-2"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="5.0.8" expanded="true" height="76" name="Generate Attributes (2)" width="90" x="45" y="120">
        <list key="function_descriptions">
          <parameter key="date" value="&quot;%{t}&quot;"/>
        </list>
      </operator>
      <operator activated="true" class="select_attributes" compatibility="5.0.8" expanded="true" height="76" name="Select Attributes" width="90" x="61" y="253">
        <parameter key="attribute_filter_type" value="subset"/>
        <parameter key="attributes" value="att1|label"/>
        <parameter key="invert_selection" value="true"/>
      </operator>
      <operator activated="true" class="nominal_to_date" compatibility="5.0.8" expanded="true" height="76" name="Nominal to Date (2)" width="90" x="45" y="390">
        <parameter key="attribute_name" value="date"/>
        <parameter key="date_format" value="y_M_d-a_h_m_s"/>
      </operator>
      <operator activated="true" class="adjust_date" compatibility="5.0.8" expanded="true" height="76" name="Adjust Date (2)" width="90" x="179" y="390">
        <parameter key="attribute_name" value="date"/>
        <list key="adjustments">
          <parameter key="%{added_days}" value="2"/>
        </list>
      </operator>
      <operator activated="true" class="date_to_nominal" compatibility="5.0.8" expanded="true" height="76" name="Date to Nominal (2)" width="90" x="246" y="120">
        <parameter key="attribute_name" value="date"/>
        <parameter key="date_format" value="yyyy-MM-dd"/>
      </operator>
      <operator activated="true" class="extract_macro" compatibility="5.0.8" expanded="true" height="60" name="Extract Macro (2)" width="90" x="313" y="255">
        <parameter key="macro" value="currdate"/>
        <parameter key="macro_type" value="data_value"/>
        <parameter key="attribute_name" value="date"/>
        <parameter key="example_index" value="1"/>
      </operator>
      <operator activated="true" class="generate_attributes" compatibility="5.0.8" expanded="true" height="76" name="Generate Attributes" width="90" x="380" y="120">
        <list key="function_descriptions">
          <parameter key="currdate" value="&quot;%{currdate}&quot;"/>
        </list>
      </operator>
      <connect from_op="Generate Data (2)" from_port="output" to_op="Set Macro (3)" to_port="through 1"/>
      <connect from_op="Set Macro (3)" from_port="through 1" to_op="Generate Attributes (2)" to_port="example set input"/>
      <connect from_op="Generate Attributes (2)" from_port="example set output" to_op="Select Attributes" to_port="example set input"/>
      <connect from_op="Select Attributes" from_port="example set output" to_op="Nominal to Date (2)" to_port="example set input"/>
      <connect from_op="Nominal to Date (2)" from_port="example set output" to_op="Adjust Date (2)" to_port="example set input"/>
      <connect from_op="Adjust Date (2)" from_port="example set output" to_op="Date to Nominal (2)" to_port="example set input"/>
      <connect from_op="Date to Nominal (2)" from_port="example set output" to_op="Extract Macro (2)" to_port="example set"/>
      <connect from_op="Extract Macro (2)" from_port="example set" 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>