The object X
is reflected through the origin.
That is, each point in X
with coordinates
\((x,y)\) is mapped to the position \((-x, -y)\).
This is equivalent to applying the affine transformation with matrix
diag(c(-1,-1))
. It is also equivalent to rotation about the origin
by 180 degrees.
The command reflect
is generic, with a method for
pixel images and a default method.