next up previous contents
Next: determineConstraints(Metadata inboolean forwards) Up: Implementing New CoordTransform Classes Previous: Implementing New CoordTransform Classes

getInAxes(), getOutAxes()

These methods return the minimum number of axes that are needed in an input position and returned in an output position. For the forward transform, getInAxes() returns the number of axes needed in the input position given to forward(). This number is also the number of axes returned in the output position from the reverse() method. Likewise, getOutAxes() returns the number of output axes returned by the forward(), which is the same number of axes required in the input position to reverse(). These methods can be called as a way of determining if the transform can be applied to a position or system. If the number of axes is less than these numbers, the transform cannont be applied. By default, both methods return zero; that means that given an empty Axis Index List, a position will legally pass through the transform method unchanged. A transform that operates on longitude and latitude would usually return 2 as the minimum number of required axes.



Ray Plante
Mon Aug 25 15:16:12 CDT 1997