org.knime.base.node.preproc.sample
Class SamplingNodeModel

java.lang.Object
  extended by org.knime.core.node.NodeModel
      extended by org.knime.base.node.preproc.sample.AbstractSamplingNodeModel
          extended by org.knime.base.node.preproc.sample.SamplingNodeModel

public class SamplingNodeModel
extends AbstractSamplingNodeModel

NodeModel implementation to sample rows from an input table, thus, this node has one in- and one outport.

Author:
Bernd Wiswedel, University of Konstanz

Constructor Summary
SamplingNodeModel()
          Empty constructor, sets port count in super.
 
Method Summary
protected  DataTableSpec[] configure(DataTableSpec[] inSpecs)
          This function is called whenever the derived model should re-configure its output DataTableSpecs.
protected  BufferedDataTable[] execute(BufferedDataTable[] inData, ExecutionContext exec)
          This function is invoked by the Node#executeNode() method of the node (through the #executeModel(BufferedDataTable[],ExecutionMonitor) method)only after all predecessor nodes have been successfully executed and all data is therefore available at the input ports.
 
Methods inherited from class org.knime.base.node.preproc.sample.AbstractSamplingNodeModel
checkSettings, getSamplingRowFilter, getSettings, hasBeenConfigured, loadInternals, loadValidatedSettingsFrom, reset, saveInternals, saveSettingsTo, validateSettings
 
Methods inherited from class org.knime.core.node.NodeModel
addWarningListener, configure, continueLoop, execute, executeModel, getInHiLiteHandler, getLoopEndNode, getLoopStartNode, getNrInPorts, getNrOutPorts, getOutHiLiteHandler, getWarningMessage, notifyViews, notifyWarningListeners, peekFlowVariableDouble, peekFlowVariableInt, peekFlowVariableString, peekScopeVariableDouble, peekScopeVariableInt, peekScopeVariableString, pushFlowVariableDouble, pushFlowVariableInt, pushFlowVariableString, pushScopeVariableDouble, pushScopeVariableInt, pushScopeVariableString, removeWarningListener, setInHiLiteHandler, setWarningMessage, stateChanged
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SamplingNodeModel

public SamplingNodeModel()
Empty constructor, sets port count in super.

Method Detail

execute

protected BufferedDataTable[] execute(BufferedDataTable[] inData,
                                      ExecutionContext exec)
                               throws Exception
This function is invoked by the Node#executeNode() method of the node (through the #executeModel(BufferedDataTable[],ExecutionMonitor) method)only after all predecessor nodes have been successfully executed and all data is therefore available at the input ports. Implement this function with your task in the derived model.

The input data is available in the given array argument inData and is ensured to be neither null nor contain null elements.

In order to create output data, you need to create objects of class BufferedDataTable. Use the execution context argument to create BufferedDataTable.

Overrides:
execute in class NodeModel
Parameters:
inData - An array holding DataTable elements, one for each input.
exec - The execution monitor for this execute method. It provides us with means to create new BufferedDataTable. Additionally, it should be asked frequently if the execution should be interrupted and throws an exception then. This exception might me caught, and then after closing all data streams, been thrown again. Also, if you can tell the progress of your task, just set it in this monitor.
Returns:
An array of non- null DataTable elements with the size of the number of outputs. The result of this execution.
Throws:
Exception - If you must fail the execution. Try to provide a meaningful error message in the exception as it will be displayed to the user.Please be advised to check frequently the canceled status by invoking ExecutionMonitor#checkCanceled which will throw an CanceledExcecutionException and abort the execution.

configure

protected DataTableSpec[] configure(DataTableSpec[] inSpecs)
                             throws InvalidSettingsException
This function is called whenever the derived model should re-configure its output DataTableSpecs. Based on the given input data table spec(s) and the current model's settings, the derived model has to calculate the output data table spec and return them.

The passed DataTableSpec elements are never null but can be empty. The model may return null data table spec(s) for the outputs. But still, the model may be in an executable state. Note, after the model has been executed this function will not be called anymore, as the output DataTableSpecs are then being pulled from the output DataTables. A derived NodeModel that cannot provide any DataTableSpecs at its outputs before execution (because the table structure is unknown at this point) can return an array containing just null elements.

Implementation note: This method is called from the NodeModel.configure(PortObjectSpec[]) method unless that method is overwritten.

Overrides:
configure in class NodeModel
Parameters:
inSpecs - An array of DataTableSpecs (as many as this model has inputs). Do NOT modify the contents of this array. None of the DataTableSpecs in the array can be null but empty. If the predecessor node is not yet connected, or doesn't provide a DataTableSpecs at its output port.
Returns:
An array of DataTableSpecs (as many as this model has outputs) They will be propagated to connected successor nodes. null DataTableSpec elements are changed to empty once.
Throws:
InvalidSettingsException - if the #configure() failed, that is, the settings are inconsistent with given DataTableSpec elements.


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University of Konstanz, Germany.
Chair for Bioinformatics and Information Mining, Prof. Dr. Michael R. Berthold.
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