Example usage for weka.core Attribute setStringValue

Introduction

In this page you can find the example usage for weka.core Attribute setStringValue.

Prototype

public void setStringValue(String value) 

Source Link

Document

Clear the map and list of values and set them to contain just the supplied value

Usage

From source file:org.pentaho.di.scoring.WekaScoringData.java

License:Open Source License

/**
 * Helper method that constructs an Instance to input to the Weka model based
 * on incoming Kettle fields and pre-constructed attribute-to-field mapping
 * data.//from  w ww.  j  a  v a2 s  . c  o  m
 *
 * @param inputMeta      a <code>RowMetaInterface</code> value
 * @param inputRow       an <code>Object</code> value
 * @param mappingIndexes an <code>int</code> value
 * @param model          a <code>WekaScoringModel</code> value
 * @return an <code>Instance</code> value
 */
private Instance constructInstance(RowMetaInterface inputMeta, Object[] inputRow, int[] mappingIndexes,
        WekaScoringModel model, boolean freshVector) {

    Instances header = model.getHeader();

    // Re-use this array (unless told otherwise) to avoid an object creation
    if (m_vals == null || freshVector) {
        m_vals = new double[header.numAttributes()];
    }

    for (int i = 0; i < header.numAttributes(); i++) {

        if (mappingIndexes[i] >= 0) {
            try {
                Object inputVal = inputRow[mappingIndexes[i]];

                Attribute temp = header.attribute(i);
                ValueMetaInterface tempField = inputMeta.getValueMeta(mappingIndexes[i]);
                int fieldType = tempField.getType();

                // Check for missing value (null or empty string)
                if (tempField.isNull(inputVal)) {
                    m_vals[i] = Utils.missingValue();
                    continue;
                }

                switch (temp.type()) {
                case Attribute.NUMERIC: {
                    if (fieldType == ValueMetaInterface.TYPE_BOOLEAN) {
                        Boolean b = tempField.getBoolean(inputVal);
                        if (b.booleanValue()) {
                            m_vals[i] = 1.0;
                        } else {
                            m_vals[i] = 0.0;
                        }
                    } else if (fieldType == ValueMetaInterface.TYPE_INTEGER) {
                        Long t = tempField.getInteger(inputVal);
                        m_vals[i] = t.longValue();
                    } else {
                        Double n = tempField.getNumber(inputVal);
                        m_vals[i] = n.doubleValue();
                    }
                }
                    break;
                case Attribute.NOMINAL: {
                    String s = tempField.getString(inputVal);
                    // now need to look for this value in the attribute
                    // in order to get the correct index
                    int index = temp.indexOfValue(s);
                    if (index < 0) {
                        // set to missing value
                        m_vals[i] = Utils.missingValue();
                    } else {
                        m_vals[i] = index;
                    }
                }
                    break;
                case Attribute.STRING: {
                    String s = tempField.getString(inputVal);
                    // Set the attribute in the header to contain just this string value
                    temp.setStringValue(s);
                    m_vals[i] = 0.0;
                    break;
                }
                default:
                    m_vals[i] = Utils.missingValue();
                }
            } catch (Exception e) {
                m_vals[i] = Utils.missingValue();
            }
        } else {
            // set to missing value
            m_vals[i] = Utils.missingValue();
        }
    }

    Instance newInst = new DenseInstance(1.0, m_vals);
    newInst.setDataset(header);
    return newInst;
}

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