/**
* @param i
* @param j
* @return
*/
public double[] componentCovar(int i, int j) {
if (m_P == null) {
return null;
}
int n = m_n - m_start;
double[] c = new double[n];
for (int z = 0; z < n; ++z) {
c[z] = m_P.matrix(z).get(i, j) * m_ser2;
}
return c;
}
/**
* @param z
* @return
*/
public double[] zvariance(DataBlock z) {
if (m_P == null) {
return null;
}
if (m_r != z.getLength()) {
return null;
}
int iz = check(z);
double[] var = new double[m_n - m_start];
if (iz >= 0) {
return componentVar(iz);
} else {
for (int i = 0; i < m_n - m_start; ++i) {
var[i] = SymmetricMatrix.quadraticForm(m_P.matrix(i), z) * m_ser2;
}
}
return var;
}
/**
* @param idx
* @param z
* @return
*/
public double zvariance(int idx, DataBlock z) {
return m_P == null || idx < m_start
? Double.NaN
: SymmetricMatrix.quadraticForm(m_P.matrix(idx - m_start), z) * m_ser2;
}
/**
* @param idx
* @return
*/
public SubMatrix P(int idx) {
return (m_P == null || idx < m_start) ? null : m_P.matrix(idx - m_start);
}