main/src/georegression/geometry/GeometryMath_F64.java
public static DMatrixRMaj crossMatrix( double x0, double x1, double x2, DMatrixRMaj ret ) {
		if( ret == null ) {
			ret = new DMatrixRMaj( 3, 3 );
		} else {
			ret.zero();
		}

		ret.set( 0, 1, -x2 );
		ret.set( 0, 2, x1 );
		ret.set( 1, 0, x2 );
		ret.set( 1, 2, -x0 );
		ret.set( 2, 0, -x1 );
		ret.set( 2, 1, x0 );

		return ret;
	}
public static DMatrixRMaj crossMatrix( double x0, double x1, double x2, DMatrixRMaj ret ) {
		if( ret == null ) {
			ret = new DMatrixRMaj( 3, 3 );
		} else {
			ret.zero();
		}

		ret.set( 0, 1, -x2 );
		ret.set( 0, 2, x1 );
		ret.set( 1, 0, x2 );
		ret.set( 1, 2, -x0 );
		ret.set( 2, 0, -x1 );
		ret.set( 2, 1, x0 );

		return ret;
	}
Creates a skew symmetric cross product matrix from the provided tuple.

@param x0  Element 0.
@param x1  Element 1.
@param x2  Element 2.
@param ret If not null the results are stored here, otherwise a new matrix is created.
@return Skew symmetric cross product matrix.