public static void main(String... args) {
Stopwatch.enter();
Stopwatch.p();
SparseMatrix A = Matrix.sparse(4000, 10000);
Random rand = new Random(1);
for (int i = 0; i < A.rowCount(); i++) {
for (int j = 0; j < A.columnCount(); j++) {
if (rand.nextDouble() > 0.2) continue;
A.put(i, j, rand.nextDouble() * 23);
}
}