@Override
public ArrayVector matrixVectorMultiplication(Matrix m) {
if (m.getN() != getSize()) {
throw new IllegalArgumentException(
"The matrix's width (N) must " + "be the same as this vector's size");
}
ArrayVector result = new ArrayVector(getSize());
// result[i] = sum_j(this[j] * m[i][j])
boolean multithread = false; // doesn't exit yet ;-(
if (!multithread) {
float temp;
for (int i = 0; i < m.getM(); i++) {
temp = 0.0f;
for (int j : m.getNonZeroRowIndecies(i)) {
temp += getValue(j) * m.getValue(i, j);
}
result.setValue(i, temp);
}
} else {
int numThreads = multiplier.length;
CountDownLatch mainLatch = new CountDownLatch(numThreads);
int perThread = m.getM() / numThreads;
for (int i = 0; i < numThreads; i++) {
int startIndex = i * perThread;
int endIndex = startIndex + perThread - 1;
if (i + 1 == numThreads) {
endIndex = m.getM() - 1;
}
multiplier[i] = new MatrixVectorMultiplier(m, result, startIndex, endIndex);
multiplier[i].setLatch(mainLatch);
executor.execute(multiplier[i]);
}
try {
mainLatch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return result;
}
@Override
public ArrayVector vectorSubtraction(Vector v) {
ArrayVector result = new ArrayVector(vectorValues);
result.subtract(v);
return result;
}
@Override
public ArrayVector scalarMultiplication(float s) {
ArrayVector result = new ArrayVector(vectorValues);
result.multiply(s);
return result;
}
@Override
public ArrayVector vectorAddition(Vector v) {
ArrayVector result = new ArrayVector(vectorValues);
result.add(v);
return result;
}