Editing Transformation matrix (section)

===Squeezing===

If the two stretches above are combined with reciprocal values, then the transformation matrix represents a [[squeeze mapping]]:
<math display="block">\begin{bmatrix} k &  0 \\ 0 & 1/k \end{bmatrix} .</math>
A square with sides parallel to the axes is transformed to a rectangle that has the same area as the square. The reciprocal stretch and compression leave the area invariant.