Returns the positive |
real value of smallest magnitude
\epsilon which an element of a
contain. An element of a
Transform may also contain
The value \epsilon is used for in the
clean() (see Transform Reference; Cleaning).
It will also be used for comparing
Transforms, when I've added
the equality operator
epsilon() returns different values, depending on whether
float (the default),
double, it returns 0.000000001.
Please note: I haven't tested whether 0.000000001 is a good
value yet, so users should be aware of this if they set
The way to test this is to transform two different
t_1 and t_2
using different rotations in such a way that the end
result should be the same for both
Let \epsilon stand for the value returned by
If for all sets of
corresponding elements E_1 and E_2 of t_1 and
t_2, ||E_1| - |E_2|| \le \epsilon, then
\epsilon is a good value.
It will be easier to test this when I've added
Rotation causes a significant loss of precision to due to the use of the
cos() functions. Therefore, neither
(see Point Reference; Returning Information) can be as small as I'd like them to be. If they are two
small, operations that test for equality of
Points will return
false for objects that should be equal.