1[5 x 5 x 5]=>[5 x 15 x 20], interp err = 2.4813e-01 2[10 x 10 x 10]=>[10 x 30 x 40], interp err = 5.7117e-02 3[20 x 20 x 20]=>[20 x 60 x 80], interp err = 1.4121e-02 4