2.2 The class hierarchy for DUIM-Geometry

2.2.2 Error classes provided by DUIM-Geometry

The DUIM-Geometry library exposes a number of errors that can be signalled in certain circumstances. They are shown in Table 2.2. All the errors shown are subclasses of the <error> class. Note that the subclasses of <transform-error> are all specific to particular errors.

Table 2.2 The <transform-error> class and its subclasses
<transform-error>
	<transform-underspecified>
		<reflection-<underspecified>

	<singular-transform>

<transform-error>
: The superclass of all error conditions signalled when there is an error with a transform.
<transform-underspecified>
: The error that is signalled when make-3-point-transform is given three colinear image points.
<reflection-<underspecified>
: The error that is signalled when make-reflection-transform is given two coincident points.
<singular-transform>
: The error that is signalled when invert-transform is called on a singular transform, that is, a transform that has no inverse.