Package weka.core.converters

Class CSVLoader

  • All Implemented Interfaces:
    java.io.Serializable, BatchConverter, FileSourcedConverter, IncrementalConverter, Loader, EnvironmentHandler, OptionHandler, RevisionHandler
    public class CSVLoader
extends AbstractFileLoader
implements BatchConverter, IncrementalConverter, OptionHandler
    Reads a source that is in comma separated format (the default). One can also change the column separator from comma to tab or another character, specify string enclosures, specify whether aheader row is present or not and specify which attributes are to beforced to be nominal or date. Can operate in batch or incremental mode. In batch mode, a buffer is used to process a fixed number of rows in memory at any one time and the data is dumped to a temporary file. This allows the legal values for nominal attributes to be automatically determined. The final ARFF file is produced in a second pass over the temporary file using the structure determined on the first pass. In incremental mode, the first buffer full of rows is used to determine the structure automatically. Following this all rows are read and output incrementally. An error will occur if a row containing nominal values not seen in the initial buffer is encountered. In this case, the size of the initial buffer can be increased, or the user can explicitly provide the legal values of all nominal attributes using the -L (setNominalLabelSpecs) option.

    Valid options are: 

     -H
  No header row present in the data.
     -N <range>
  The range of attributes to force type to be NOMINAL.
  'first' and 'last' are accepted as well.
  Examples: "first-last", "1,4,5-27,50-last"
  (default: -none-)
     -L <nominal label spec>
  Optional specification of legal labels for nominal
  attributes. May be specified multiple times.
  Batch mode can determine this
  automatically (and so can incremental mode if
  the first in memory buffer load of instances
  contains an example of each legal value). The
  spec contains two parts separated by a ":". The
  first part can be a range of attribute indexes or
  a comma-separated list off attruibute names; the
  second part is a comma-separated list of labels. E.g
  "1,2,4-6:red,green,blue" or "att1,att2:red,green,blue"
     -S <range>
  The range of attribute to force type to be STRING.
  'first' and 'last' are accepted as well.
  Examples: "first-last", "1,4,5-27,50-last"
  (default: -none-)
     -D <range>
  The range of attribute to force type to be DATE.
  'first' and 'last' are accepted as well.
  Examples: "first-last", "1,4,5-27,50-last"
  (default: -none-)
     -format <date format>
  The date formatting string to use to parse date values.
  (default: "yyyy-MM-dd'T'HH:mm:ss")
     -R <range>
  The range of attribute to force type to be NUMERIC.
  'first' and 'last' are accepted as well.
  Examples: "first-last", "1,4,5-27,50-last"
  (default: -none-)
     -M <str>
  The string representing a missing value.
  (default: ?)
     -F <separator>
  The field separator to be used.
  '\t' can be used as well.
  (default: ',')
     -E <enclosures>
  The enclosure character(s) to use for strings.
  Specify as a comma separated list (e.g. ",' (default: ",')
     -B <num>
  The size of the in memory buffer (in rows).
  (default: 100)
    Version:
    $Revision: 14116 $
    Author:
    Mark Hall (mhall{[at]}pentaho{[dot]}com)
    See Also:
    Serialized Form

    • Field Detail

      • FILE_EXTENSION

        public static java.lang.String FILE_EXTENSION
        the file extension.

    • Constructor Detail

      • CSVLoader

        public CSVLoader()
        default constructor.

    • Method Detail

      • main

        public static void main​(java.lang.String[] args)
        Main method.
        Parameters:
        args - should contain the name of an input file.

      • globalInfo

        public java.lang.String globalInfo()
        Returns a string describing this attribute evaluator.
        Returns:
        a description of the evaluator suitable for displaying in the explorer/experimenter gui

      • getRevision

        public java.lang.String getRevision()
        Description copied from interface: RevisionHandler
        Returns the revision string.
        Specified by:
        getRevision in interface RevisionHandler
        Returns:
        the revision

      • noHeaderRowPresentTipText

        public java.lang.String noHeaderRowPresentTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getNoHeaderRowPresent

        public boolean getNoHeaderRowPresent()
        Get whether there is no header row in the data.
        Returns:
        true if there is no header row in the data

      • setNoHeaderRowPresent

        public void setNoHeaderRowPresent​(boolean b)
        Set whether there is no header row in the data.
        Parameters:
        b - true if there is no header row in the data

      • getMissingValue

        public java.lang.String getMissingValue()
        Returns the current placeholder for missing values.
        Returns:
        the placeholder

      • setMissingValue

        public void setMissingValue​(java.lang.String value)
        Sets the placeholder for missing values.
        Parameters:
        value - the placeholder

      • missingValueTipText

        public java.lang.String missingValueTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getStringAttributes

        public java.lang.String getStringAttributes()
        Returns the current attribute range to be forced to type string.
        Returns:
        the range

      • setStringAttributes

        public void setStringAttributes​(java.lang.String value)
        Sets the attribute range to be forced to type string.
        Parameters:
        value - the range

      • stringAttributesTipText

        public java.lang.String stringAttributesTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getNominalAttributes

        public java.lang.String getNominalAttributes()
        Returns the current attribute range to be forced to type nominal.
        Returns:
        the range

      • setNominalAttributes

        public void setNominalAttributes​(java.lang.String value)
        Sets the attribute range to be forced to type nominal.
        Parameters:
        value - the range

      • nominalAttributesTipText

        public java.lang.String nominalAttributesTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getNumericAttributes

        public java.lang.String getNumericAttributes()
        Gets the attribute range to be forced to type numeric
        Returns:
        the range

      • setNumericAttributes

        public void setNumericAttributes​(java.lang.String value)
        Sets the attribute range to be forced to type numeric
        Parameters:
        value - the range

      • numericAttributesTipText

        public java.lang.String numericAttributesTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getDateFormat

        public java.lang.String getDateFormat()
        Get the format to use for parsing date values.
        Returns:
        the format to use for parsing date values.

      • setDateFormat

        public void setDateFormat​(java.lang.String value)
        Set the format to use for parsing date values.
        Parameters:
        value - the format to use.

      • dateFormatTipText

        public java.lang.String dateFormatTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getDateAttributes

        public java.lang.String getDateAttributes()
        Returns the current attribute range to be forced to type date.
        Returns:
        the range.

      • setDateAttributes

        public void setDateAttributes​(java.lang.String value)
        Set the attribute range to be forced to type date.
        Parameters:
        value - the range

      • dateAttributesTipText

        public java.lang.String dateAttributesTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • enclosureCharactersTipText

        public java.lang.String enclosureCharactersTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getEnclosureCharacters

        public java.lang.String getEnclosureCharacters()
        Get the character(s) to use/recognize as string enclosures
        Returns:
        the characters to use as string enclosures

      • setEnclosureCharacters

        public void setEnclosureCharacters​(java.lang.String enclosure)
        Set the character(s) to use/recognize as string enclosures
        Parameters:
        enclosure - the characters to use as string enclosures

      • getFieldSeparator

        public java.lang.String getFieldSeparator()
        Returns the character used as column separator.
        Returns:
        the character to use

      • setFieldSeparator

        public void setFieldSeparator​(java.lang.String value)
        Sets the character used as column separator.
        Parameters:
        value - the character to use

      • fieldSeparatorTipText

        public java.lang.String fieldSeparatorTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getBufferSize

        public int getBufferSize()
        Get the buffer size to use - i.e. the number of rows to load and process in memory at any one time
        Returns:

      • setBufferSize

        public void setBufferSize​(int buff)
        Set the buffer size to use - i.e. the number of rows to load and process in memory at any one time
        Parameters:
        buff - the buffer size (number of rows)

      • bufferSizeTipText

        public java.lang.String bufferSizeTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • getNominalLabelSpecs

        public java.lang.Object[] getNominalLabelSpecs()
        Get label specifications for nominal attributes.
        Returns:
        an array of label specifications

      • setNominalLabelSpecs

        public void setNominalLabelSpecs​(java.lang.Object[] specs)
        Set label specifications for nominal attributes.
        Parameters:
        specs - an array of label specifications

      • nominalLabelSpecsTipText

        public java.lang.String nominalLabelSpecsTipText()
        Returns the tip text for this property.
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • listOptions

        public java.util.Enumeration<Option> listOptions()
        Description copied from interface: OptionHandler
        Returns an enumeration of all the available options..
        Specified by:
        listOptions in interface OptionHandler
        Returns:
        an enumeration of all available options.

      • getOptions

        public java.lang.String[] getOptions()
        Description copied from interface: OptionHandler
        Gets the current option settings for the OptionHandler.
        Specified by:
        getOptions in interface OptionHandler
        Returns:
        the list of current option settings as an array of strings

      • setOptions

        public void setOptions​(java.lang.String[] options)
                throws java.lang.Exception
        Description copied from interface: OptionHandler
        Sets the OptionHandler's options using the given list. All options will be set (or reset) during this call (i.e. incremental setting of options is not possible).
        Specified by:
        setOptions in interface OptionHandler
        Parameters:
        options - the list of options as an array of strings
        Throws:
        java.lang.Exception - if an option is not supported

      • getNextInstance

        public Instance getNextInstance​(Instances structure)
                         throws java.io.IOException
        Description copied from interface: Loader
        Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get. If the structure hasn't yet been determined by a call to getStructure then method should do so before returning the next instance in the data set. If it is not possible to read the data set incrementally (ie. in cases where the data set structure cannot be fully established before all instances have been seen) then an exception should be thrown.
        Specified by:
        getNextInstance in interface Loader
        Specified by:
        getNextInstance in class AbstractLoader
        Parameters:
        structure - the dataset header information, will get updated in case of string or relational attributes
        Returns:
        the next instance in the data set as an Instance object or null if there are no more instances to be read
        Throws:
        java.io.IOException - if there is an error during parsing or if getDataSet has been called on this source (either incremental or batch loading can be used, not both).

      • getDataSet

        public Instances getDataSet()
                     throws java.io.IOException
        Description copied from interface: Loader
        Return the full data set. If the structure hasn't yet been determined by a call to getStructure then the method should do so before processing the rest of the data set.
        Specified by:
        getDataSet in interface Loader
        Specified by:
        getDataSet in class AbstractLoader
        Returns:
        the full data set as an Instances object
        Throws:
        java.io.IOException - if there is an error during parsing or if getNextInstance has been called on this source (either incremental or batch loading can be used, not both). 
         
    public_normal_behavior
      requires: model_sourceSupplied == true
                && (* successful parse *);
      modifiable: model_structureDetermined;
      ensures: \result != null
               && \result.numInstances() >= 0
               && model_structureDetermined == true;
  also
    public_exceptional_behavior
      requires: model_sourceSupplied == false
                || (* unsuccessful parse *);
      signals: (IOException);

      • setSource

        public void setSource​(java.io.InputStream input)
               throws java.io.IOException
        Resets the Loader object and sets the source of the data set to be the supplied Stream object.
        Specified by:
        setSource in interface Loader
        Overrides:
        setSource in class AbstractLoader
        Parameters:
        input - the input stream
        Throws:
        java.io.IOException - if an error occurs

      • setSource

        public void setSource​(java.io.File file)
               throws java.io.IOException
        Resets the Loader object and sets the source of the data set to be the supplied File object.
        Specified by:
        setSource in interface Loader
        Overrides:
        setSource in class AbstractFileLoader
        Parameters:
        file - the source file.
        Throws:
        java.io.IOException - if an error occurs

      • getStructure

        public Instances getStructure()
                       throws java.io.IOException
        Description copied from interface: Loader
        Determines and returns (if possible) the structure (internally the header) of the data set as an empty set of instances.
        Specified by:
        getStructure in interface Loader
        Specified by:
        getStructure in class AbstractLoader
        Returns:
        the structure of the data set as an empty set of Instances
        Throws:
        java.io.IOException - if there is no source or parsing fails 
         
    public_normal_behavior
      requires: model_sourceSupplied == true
                && model_structureDetermined == false
                && (* successful parse *);
      modifiable: model_structureDetermined;
      ensures: \result != null
               && \result.numInstances() == 0
               && model_structureDetermined == true;
  also
    public_exceptional_behavior
      requires: model_sourceSupplied == false
                || (* unsuccessful parse *);
      signals: (IOException);

      • reset

        public void reset()
           throws java.io.IOException
        Description copied from class: AbstractFileLoader
        Resets the loader ready to read a new data set
        Specified by:
        reset in interface Loader
        Overrides:
        reset in class AbstractFileLoader
        Throws:
        java.io.IOException - if something goes wrong