public DoubleVector getRowVector(int row) {
int cols = columns();
DoubleVector vec = new DenseVector(cols);
for (int c = 0; c < cols; ++c) {
vec.set(c, get(row, c));
}
return vec;
}
/** Generates a simple random vector. */
private static DoubleVector generateInitialVector(int length, double mean, double std) {
DoubleVector vector = new DenseVector(length);
for (int i = 0; i < length; ++i) {
double v = RANDOM.nextGaussian();
v = std * v + mean;
vector.set(i, v);
}
return vector;
}
/**
* @param length CAUTION: This value is ignored
* @return A random vector that is orthogonal to all previously created vectors
*/
public DoubleVector generate() {
if (generatedVectors.size() == vectorLength)
throw new IllegalArgumentException("Too many vectors have been generated");
DoubleVector vector = generateInitialVector(vectorLength, mean, std);
for (DoubleVector otherVector : generatedVectors) {
double uDotV = dotProduct(otherVector, vector);
double uDotU = dotProduct(otherVector, otherVector);
for (int i = 0; i < vectorLength; ++i) {
double projection = otherVector.get(i) * uDotV / uDotU;
vector.set(i, vector.get(i) - projection);
}
}
generatedVectors.add(vector);
return vector;
}