INVERSE
The transformation that undoes another.
Syntax
INVERSE(transformation)
| Argument | Meaning |
|---|---|
| transformation | A transformation, such as TRANSLATE([5,5]) or ROTATE(P0,90). |
Result
A transformation: a position moved by transformation and then by its inverse is back where it was.
Examples
In the example drawing:
| Expression | Gives |
|---|---|
[10,20]*INVERSE(TRANSLATE([5,5])) |
[5,15] |
[-20,10]*INVERSE(ROTATE(P0,90)) |
[10,20] |
[20,60]*INVERSE(SCALE(P0,[2,3])) |
[10,20] |
Notes
Moving elements in place uses it: a point that stays where it is while a point it is defined from moves is redefined
as (P4*INVERSE(…)), where the point it was defined from was. It is an error if the transformation flattens
everything onto a line or a point (a scale of 0), so it can't be undone.