All Packages Class Hierarchy This Package Previous Next Index WEKA's home
Class weka.filters.ResampleFilter
java.lang.Object
|
+----weka.filters.Filter
|
+----weka.filters.ResampleFilter
- public class ResampleFilter
- extends Filter
- implements OptionHandler
Produces a random subsample of a dataset. The original dataset must
fit entirely in memory. The number of instances in the generated
dataset may be specified. If the dataset has a (nominal) class
attribute, the filter can be made to maintain the class
distribution in the subsample, or to bias the class distribution toward
a uniform distribution. When used in batch mode, subsequent batches are
not resampled.
Valid options are:
-S num
Specify the random number seed (default 1).
-B num
Specify a bias towards uniform class distribution. 0 = distribution
in input data, 1 = uniform class distribution (default 0).
-Z percent
Specify the size of the output dataset, as a percentage of the input
dataset (default 100).
- Version:
- $Revision: 1.10 $
- Author:
- Len Trigg (len@intelligenesis.net)
ResampleFilter()
-
batchFinished()
- Signify that this batch of input to the filter is finished.
getBiasToUniformClass()
- Gets the bias towards a uniform class.
getOptions()
- Gets the current settings of the filter.
getRandomSeed()
- Gets the random number seed.
getSampleSizePercent()
- Gets the subsample size as a percentage of the original set.
input(Instance)
- Input an instance for filtering.
listOptions()
- Returns an enumeration describing the available options
main(String[])
- Main method for testing this class.
setBiasToUniformClass(double)
- Sets the bias towards a uniform class.
setInputFormat(Instances)
- Sets the format of the input instances.
setOptions(String[])
- Parses a list of options for this object.
setRandomSeed(int)
- Sets the random number seed.
setSampleSizePercent(double)
- Sets the size of the subsample, as a percentage of the original set.
ResampleFilter
public ResampleFilter()
listOptions
public java.util.Enumeration listOptions()
Returns an enumeration describing the available options
- Returns:
- an enumeration of all the available options
setOptions
public void setOptions(java.lang.String options[]) throws java.lang.Exception
Parses a list of options for this object. Valid options are:
-S num
Specify the random number seed (default 1).
-B num
Specify a bias towards uniform class distribution. 0 = distribution
in input data, 1 = uniform class distribution (default 0).
-Z percent
Specify the size of the output dataset, as a percentage of the input
dataset (default 100).
- Parameters:
options
- the list of options as an array of strings
- Throws:
- java.lang.Exception - if an option is not supported
getOptions
public java.lang.String[] getOptions()
Gets the current settings of the filter.
- Returns:
- an array of strings suitable for passing to setOptions
getBiasToUniformClass
public double getBiasToUniformClass()
Gets the bias towards a uniform class. A value of 0 leaves the class
distribution as-is, a value of 1 ensures the class distributions are
uniform in the output data.
- Returns:
- the current bias
setBiasToUniformClass
public void setBiasToUniformClass(double newBiasToUniformClass)
Sets the bias towards a uniform class. A value of 0 leaves the class
distribution as-is, a value of 1 ensures the class distributions are
uniform in the output data.
- Parameters:
newBiasToUniformClass
- the new bias value, between 0 and 1.
getRandomSeed
public int getRandomSeed()
Gets the random number seed.
- Returns:
- the random number seed.
setRandomSeed
public void setRandomSeed(int newSeed)
Sets the random number seed.
- Parameters:
newSeed
- the new random number seed.
getSampleSizePercent
public double getSampleSizePercent()
Gets the subsample size as a percentage of the original set.
- Returns:
- the subsample size
setSampleSizePercent
public void setSampleSizePercent(double newSampleSizePercent)
Sets the size of the subsample, as a percentage of the original set.
- Parameters:
newSampleSizePercent
- the subsample set size, between 0 and 100.
setInputFormat
public boolean setInputFormat(Instances instanceInfo) throws java.lang.Exception
Sets the format of the input instances.
- Parameters:
instanceInfo
- an Instances object containing the input
instance structure (any instances contained in the object are
ignored - only the structure is required).
- Returns:
- true if the outputFormat may be collected immediately
- Throws:
- java.lang.Exception - if the input format can't be set
successfully
- Overrides:
- setInputFormat in class Filter
input
public boolean input(Instance instance)
Input an instance for filtering. Filter requires all
training instances be read before producing output.
- Parameters:
instance
- the input instance
- Returns:
- true if the filtered instance may now be
collected with output().
- Throws:
- java.lang.IllegalStateException - if no input structure has been defined
- Overrides:
- input in class Filter
batchFinished
public boolean batchFinished()
Signify that this batch of input to the filter is finished.
If the filter requires all instances prior to filtering,
output() may now be called to retrieve the filtered instances.
- Returns:
- true if there are instances pending output
- Throws:
- java.lang.IllegalStateException - if no input structure has been defined
- Overrides:
- batchFinished in class Filter
main
public static void main(java.lang.String argv[])
Main method for testing this class.
- Parameters:
argv
- should contain arguments to the filter:
use -h for help
All Packages Class Hierarchy This Package Previous Next Index WEKA's home