This method reverses the transform. For example, if
`self`

represents the transform from
scene space to display space, the inverse transform
will convert a coordinate from display space back to
scene space.

The math is straightforward: multiplying the inverse of
the transform by the point's vector gives us the new
point's vector. Matrix inversion is implemented by the
`.inv()`

function in the linear algebra
sub-module `num.linalg`

.

homcoord.py

# - - - X f o r m . i n v e r t def invert ( self, p ): '''Return p transformed by the inverse of self, as a Pt. ''' return self.inverse().apply ( p )