Least squares

There are newer results available at https://github.com/optimatika/ojAlgo/wiki/Java-Matrix-Benchmark

Oracle JVM 1.8.0_161

Azul JVM 1.8.0 Zing 18.05.0.0

Oracle JVM 9.0.4

There's more Java, performance and ojAlgo related stuff at the ojAlgo blog.