Example usage for weka.core Instance replaceMissingValues

Introduction

In this page you can find the example usage for weka.core Instance replaceMissingValues.

Prototype

public void replaceMissingValues(double[] array);

Source Link

Document

Replaces all missing values in the instance with the values contained in the given array.

Usage

From source file:com.yahoo.research.scoring.classifier.NutchOnlineClassifier.java

License:Apache License

/**
 * Converts an {@link AnthURL} into an {@link Instance} which can be handled
 * by the {@link Classifier}.//from w w  w  .jav a 2 s  .co m
 * 
 * @param url
 *            the {@link AnthURL} which should be transformed/converted.
 * @return the resulting {@link Instance}.
 */
private static Instance convert(AnthURL url) {
    if (url != null) {

        Instance inst = new SparseInstance(dimension);
        inst.replaceMissingValues(replaceMissingValues);

        inst.setDataset(instances);
        inst.setValue(attributesIndex.get("class"), (url.sem ? "sem" : "nonsem"));
        inst.setValue(attributesIndex.get("sempar"), (url.semFather ? 1 : 0));
        inst.setValue(attributesIndex.get("nonsempar"), (url.nonSemFather ? 1 : 0));
        inst.setValue(attributesIndex.get("semsib"), (url.semSibling ? 1 : 0));
        inst.setValue(attributesIndex.get("nonsempar"), (url.nonSemFather ? 1 : 0));
        inst.setValue(attributesIndex.get("domain"), url.uri.getHost());
        Set<String> tokens = new HashSet<String>();

        tokens.addAll(tokenizer(url.uri.getPath()));
        tokens.addAll(tokenizer(url.uri.getQuery()));
        tokens.addAll(tokenizer(url.uri.getFragment()));
        for (String tok : tokens) {
            inst.setValue(attributesIndex.get(getAttributeNameOfHash(getHash(tok, hashTrickSize))), 1);
        }
        return inst;

    } else {
        System.out.println("Input AnthURL for convertion into instance was null.");
        return null;
    }
}

From source file:en_deep.mlprocess.manipulation.featmodif.FeatureModifierFilter.java

License:Open Source License

/**
 * Convert a single instance over if the class is nominal. The converted
 * instance is added to the end of the output queue.
 *
 * @param instance the instance to convert
 *//*from w w w.  ja  v a 2  s  .co  m*/
private void convertInstance(Instance instance) {

    double[] vals = new double[outputFormatPeek().numAttributes()];
    String[] stringVals = new String[vals.length];
    int attSoFar = 0;

    for (int j = 0; j < getInputFormat().numAttributes(); j++) {
        Attribute att = instance.attribute(j);
        if (!m_Columns.isInRange(j)) {
            vals[attSoFar] = instance.value(j);
            attSoFar++;
        } else {
            // store new string values, make double values "missing" for now (if some string
            // values are missing, the double values will remain missing)
            if (instance.value(0) == 12 && instance.value(1) == 9 && att.name().equals("sempos")) {
                attSoFar = attSoFar;
            }
            attSoFar += getAttributeOutputValue(att, instance.value(j), vals, stringVals, attSoFar);
        }
    }
    Instance inst = null;
    if (instance instanceof SparseInstance) {
        inst = new SparseInstance(instance.weight(), vals);
    } else {
        inst = new DenseInstance(instance.weight(), vals);
    }

    inst.setDataset(getOutputFormat());
    copyValues(inst, false, instance.dataset(), getOutputFormat());

    // add new string values to the output data set and to the instance
    for (int i = 0; i < stringVals.length; ++i) {
        if (stringVals[i] != null) {
            vals[i] = inst.dataset().attribute(i).addStringValue(stringVals[i]);
        }
    }
    inst.replaceMissingValues(vals);

    inst.setDataset(getOutputFormat());
    push(inst);
}

From source file:en_deep.mlprocess.manipulation.featmodif.ReplaceMissing.java

License:Open Source License

/**
 * Convert a single instance over if the class is nominal. The converted
 * instance is added to the end of the output queue.
 *
 * @param instance the instance to convert
 *///from w  ww  .  j  a v a  2  s .co m
private void convertInstance(Instance instance) {

    // create a copy of the input instance
    Instance inst = null;

    if (instance instanceof SparseInstance) {
        inst = new SparseInstance(instance.weight(), instance.toDoubleArray());
    } else {
        inst = new DenseInstance(instance.weight(), instance.toDoubleArray());
    }

    // copy the string values from this instance as well (only the existing ones)
    inst.setDataset(getOutputFormat());
    copyValues(inst, false, instance.dataset(), getOutputFormat()); // beware of weird behavior of this function (see source)!!
    inst.setDataset(getOutputFormat());

    // find the missing values to be filled + the double values for the new "missing" label and store it
    double[] vals = instance.toDoubleArray();

    for (int j = 0; j < getInputFormat().numAttributes(); j++) {

        Attribute att = instance.attribute(j);

        if (m_Columns.isInRange(j) && instance.isMissing(j)) {
            // find the "missing" value in the output nominal attribute
            if (att.isNominal()) {
                vals[j] = inst.dataset().attribute(j).indexOfValue(m_ReplVal);
            }
            // add a string value for the new "missing" label
            else if (att.isString()) {
                vals[j] = inst.dataset().attribute(j).addStringValue(m_ReplVal);
            }
        }
    }

    // fill in the missing values found
    inst.replaceMissingValues(vals);

    push(inst);
}