Case 1: txy > 0 and sx > sy |
The principal axes are counterclockwise to the current axes (because txy > 0) and no more than 45º away (because sx > sy). |
Case 2: txy < 0 and sx > sy |
The principal axes are clockwise to the current axes (because txy < 0) and no more than 45º away (because sx > sy). |
Case 3: txy > 0 and sx < sy |
The principal axes are counterclockwise to the current axes (because txy > 0) and between 45º and 90º away (because sx < sy). |
Case 4: txy < 0 and sx < sy |
The principal axes are clockwise to the current axes (because txy < 0) and between 45º and 90º away (because sx < sy). |
Case 5: txy = 0 and sx > sy |
The principal axes are aligned with the current axes (because sx > sy and txy = 0). |
Case 6: txy = 0 and sx < sy |
The principal axes are exactly 90° from the current axes (because sx < sy and txy = 0). |