<dependency> <groupId>org.unitsofmeasurement</groupId> <artifactId>unit-api</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>org.unitsofmeasurement</groupId> <artifactId>unit-ri</artifactId> <version>1.0</version> </dependency> Vector3d vector1 = new Vector3d(1, 2, 3); Vector3d vector2 = new Vector3d(4, 5, 6); Unit<Length> meterUnit = SI.METER; Quantity<Length> meter = Quantities.getQuantity(10, meterUnit); Unit<Length> footUnit = USCustomary.FOOT; Quantity<Length> foot = meter.to(footUnit); Matrix2d matrix1 = new Matrix2d(1, 2, 3, 4); Matrix2d matrix2 = new Matrix2d(5, 6, 7, 8);