BSIR                    Batch SIR method. This method can estimate
                        batch dimension reduction.
OPCA                    Online PCA method. This method can estimate
                        online eigen space.
OSIRgd                  OSIR Gradient Descent method. This method can
                        estimate online dimension reduction.
OSIRpd                  OSIR Perturbation method. This method can
                        estimate online dimension reduction.
