weka.core.Instances.variance()方法的使用及代码示例

x33g5p2x  于2022-01-21 转载在 其他  
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本文整理了Java中weka.core.Instances.variance()方法的一些代码示例，展示了Instances.variance()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Instances.variance()方法的具体详情如下：
包路径：weka.core.Instances
类名称：Instances
方法名：variance

Instances.variance介绍

[英]Computes the variance for a numeric attribute.
[中]计算数值属性的方差。

代码示例

代码示例来源：origin: com.googlecode.obvious/obviousx-weka

@Override
public double variance(int arg0) {
 return super.variance(arg0);
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

private void checkVariance(long[] weightedValues, long var, double tol) {
 double varDouble = Double.longBitsToDouble(var);
 Instances inst = getNumericInstances();
 for (int i = 0; i < weightedValues.length; i += 2) {
  inst.add(new DenseInstance(
    Double.longBitsToDouble(weightedValues[i + 1]),
    new double[]{Double.longBitsToDouble(weightedValues[i])}
    ));
 }
 
 assertEquals("Inaccurate variance calculation!",
   varDouble, inst.variance(0), Math.abs(varDouble*tol));
 assertEquals("Inaccurate variance calculation!",
   varDouble, inst.variances()[0], Math.abs(varDouble*tol));
}

代码示例来源：origin: com.googlecode.obvious/obviousx-weka

@Override
public double variance(Attribute att) {
 return super.variance(att);
}

代码示例来源：origin: Waikato/weka-trunk

private void checkVariance(long[] weightedValues, long var, double tol) {
 double varDouble = Double.longBitsToDouble(var);
 Instances inst = getNumericInstances();
 for (int i = 0; i < weightedValues.length; i += 2) {
  inst.add(new DenseInstance(
    Double.longBitsToDouble(weightedValues[i + 1]),
    new double[]{Double.longBitsToDouble(weightedValues[i])}
    ));
 }
 
 assertEquals("Inaccurate variance calculation!",
   varDouble, inst.variance(0), Math.abs(varDouble*tol));
 assertEquals("Inaccurate variance calculation!",
   varDouble, inst.variances()[0], Math.abs(varDouble*tol));
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Computes the variance for a numeric attribute.
 * 
 * @param att the numeric attribute
 * @return the variance if the attribute is numeric
 * @throws IllegalArgumentException if the attribute is not numeric
 */
public/* @pure@ */double variance(Attribute att) {
 return variance(att.index());
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Tests the behavior of the {@link Instances.variance} and
 * {@link Instances.variances} methods.
 */
public void testVarianceBehavior() {
 Instances inst;
 
 // weight <= 1 leads to NaN variance:
 inst = getNumericInstances();
 addWeightedValues(inst, 100, 0.5);
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variance(0)));
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variances()[0]));
 // even if count > 1, weight <= 1 leads to NaN variance:
 inst = getNumericInstances();
 addWeightedValues(inst, 100, 0.5, 100, 0.3);
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variance(0)));
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variances()[0]));
 
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Computes the variance for a numeric attribute.
 * 
 * @param att the numeric attribute
 * @return the variance if the attribute is numeric
 * @throws IllegalArgumentException if the attribute is not numeric
 */
public/* @pure@ */double variance(Attribute att) {
 return variance(att.index());
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Tests the behavior of the {@link Instances.variance} and
 * {@link Instances.variances} methods.
 */
public void testVarianceBehavior() {
 Instances inst;
 
 // weight <= 1 leads to NaN variance:
 inst = getNumericInstances();
 addWeightedValues(inst, 100, 0.5);
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variance(0)));
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variances()[0]));
 // even if count > 1, weight <= 1 leads to NaN variance:
 inst = getNumericInstances();
 addWeightedValues(inst, 100, 0.5, 100, 0.3);
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variance(0)));
 assertTrue("Instances.variance not NaN for weight <= 1!",
   Double.isNaN(inst.variances()[0]));
 
}

代码示例来源：origin: Waikato/weka-trunk

m_modelNormal[i][j][1] = Math.sqrt(inst.variance(j));
if ((m_modelNormal[i][j][1] <= minStdD)) {
 m_modelNormal[i][j][1] = minStdD;

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

m_modelNormal[i][j][1] = Math.sqrt(inst.variance(j));
if ((m_modelNormal[i][j][1] <= minStdD)) {
 m_modelNormal[i][j][1] = minStdD;

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

(input.classIndex() != i)) {
m_Means[i] = input.meanOrMode(i);
m_StdDevs[i] = Math.sqrt(input.variance(i));

代码示例来源：origin: Waikato/weka-trunk

(input.classIndex() != i)) {
m_Means[i] = input.meanOrMode(i);
m_StdDevs[i] = Math.sqrt(input.variance(i));

代码示例来源：origin: nz.ac.waikato.cms.weka/multiInstanceLearning

for (int i = 0; i < exi.numAttributes(); i++) {
 xBar[i] = exi.meanOrMode(i);
 sSq[i] = exi.variance(i);

代码示例来源：origin: nz.ac.waikato.cms.weka/multiInstanceLearning

var[i] = ex.relationalValue(1).variance(i);

代码示例来源：origin: Waikato/weka-trunk

double stdv = stdD.instance(i).value(j);
if (stdv < minStdD) {
 stdv = Math.sqrt(inst.variance(j));
 if (Double.isInfinite(stdv)) {
  stdv = minStdD;

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

double stdv = stdD.instance(i).value(j);
if (stdv < minStdD) {
 stdv = Math.sqrt(inst.variance(j));
 if (Double.isInfinite(stdv)) {
  stdv = minStdD;

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

public void testTypical() {
 Instances result = useFilter();
 // Number of attributes and instances shouldn't change
 assertEquals(m_Instances.numAttributes(), result.numAttributes());
 assertEquals(m_Instances.numInstances(),  result.numInstances());
 // Check conversion is OK
 for (int j = 0; j < result.numAttributes(); j++) {
  if (result.attribute(j).isNumeric()) {
 double mean = result.meanOrMode(j);
 assertTrue("Mean should be 0", Utils.eq(mean, 0));
 double stdDev = Math.sqrt(result.variance(j));
 assertTrue("StdDev should be 1 (or 0)", 
     Utils.eq(stdDev, 0) || Utils.eq(stdDev, 1));
  }
 }
}

代码示例来源：origin: Waikato/weka-trunk

public void testTypical() {
 Instances result = useFilter();
 // Number of attributes and instances shouldn't change
 assertEquals(m_Instances.numAttributes(), result.numAttributes());
 assertEquals(m_Instances.numInstances(),  result.numInstances());
 // Check conversion is OK
 for (int j = 0; j < result.numAttributes(); j++) {
  if (result.attribute(j).isNumeric()) {
 double mean = result.meanOrMode(j);
 assertTrue("Mean should be 0", Utils.eq(mean, 0));
 double stdDev = Math.sqrt(result.variance(j));
 assertTrue("StdDev should be 1 (or 0)", 
     Utils.eq(stdDev, 0) || Utils.eq(stdDev, 1));
  }
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/multiInstanceLearning

for (int i = 0; i < m_Dimension; i++) {
 m_Mean[x][i] = example.relationalValue(1).meanOrMode(i);
 m_Variance[x][i] = example.relationalValue(1).variance(i);
 if (Utils.eq(m_Variance[x][i], 0.0)) {
  m_Variance[x][i] = m_ZERO;
 for (int i = 0; i < m_Dimension; i++) {
  m_ValidM[x][i] = example.relationalValue(1).meanOrMode(i);
  m_ValidV[x][i] = example.relationalValue(1).variance(i);
  if (Utils.eq(m_ValidV[x][i], 0.0)) {
   m_ValidV[x][i] = m_ZERO;

代码示例来源：origin: nz.ac.waikato.cms.weka/partialLeastSquares

case PREPROCESSING_STANDARDIZE:
 m_ClassMean = instances.meanOrMode(instances.classIndex());
 m_ClassStdDev = StrictMath.sqrt(instances.variance(instances
  .classIndex()));
 m_Filter = new Standardize();

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