main/src/georegression/struct/se/SpecialEuclideanOps_F64.java
public static DMatrixRMaj toHomogeneous( Se2_F64 se, DMatrixRMaj ret ) {
		if( ret == null )
			ret = new DMatrixRMaj( 3, 3 );
		else {
			ret.set( 2, 0, 0 );
			ret.set( 2, 1, 0 );
		}

		final double c = se.getCosineYaw();
		final double s = se.getSineYaw();

		ret.set( 0, 0, c );
		ret.set( 0, 1, -s );
		ret.set( 1, 0, s );
		ret.set( 1, 1, c );
		ret.set( 0, 2, se.getX() );
		ret.set( 1, 2, se.getY() );
		ret.set( 2, 2, 1 );

		return ret;
	}
public static DMatrixRMaj toHomogeneous( Se2_F64 se, DMatrixRMaj ret ) {
		if( ret == null )
			ret = new DMatrixRMaj( 3, 3 );
		else {
			ret.set( 2, 0, 0 );
			ret.set( 2, 1, 0 );
		}

		final double c = se.getCosineYaw();
		final double s = se.getSineYaw();

		ret.set( 0, 0, c );
		ret.set( 0, 1, -s );
		ret.set( 1, 0, s );
		ret.set( 1, 1, c );
		ret.set( 0, 2, se.getX() );
		ret.set( 1, 2, se.getY() );
		ret.set( 2, 2, 1 );

		return ret;
	}
Converts it into a 3 by 3 homogeneous matrix.

@param se  original 2D transform
@param ret Where the results will be written to.  If null a new matrix is declared. Modified.
@return equivalent homogeneous transform.