Affine transforms are commonly used in coordinate transformation.
An affine transform is simply defined by a 4x4 double values matrix,
and are applied to coordinates by multiplying them as if they were
one 1x4 matrix.
Affine transforms are mainly used in JViews Maps for unit conversions in a transformation
path.
Another use of affine transforms is to use them to implement
Bursa Wolf transformations. The Bursa Wolf transformation is applied
to geocentric coordinates to model a seven-parameter datum change.
A seven-parameter datum is defined by the dX, dY, dZ axis
shifts, the eX, eY, eZ rotations
around the axis, and a scale factor expressed in parts per million.
The matrix to use for Bursa Wolf transformation is: