Compression
Contraction
A transformation in which
a figure grows smaller.
Compressions may be with respect to a point (compression
of a geometric figure) or with respect to the axis of
a graph (compression
of a graph).
Note: Some high
school textbooks erroneously use the word dilation to
refer to all transformations in which the figure changes size,
whether the figure becomes larger or smaller. Compression (or contraction)
refers to transformations in which the figure becomes smaller.
Dilation properly refers only to transformations in which the figure
grows
larger.
Unfortunately the English language has no word that refers collectively
to both
stretching
and shrinking.
See
also
Dilation
of a geometric figure, dilation
of a graph
