In mathematics, a rule for changing a geometric figure or algebraic expression into another, usually accompanied by a rule for transforming it back.
In geometry and topology , a transformation (e.g., flipping horizontally or vertically, rotating, or stretching vertically or horizontally) moves each point in a figure or graph to another position. A graph also undergoes a transformation when its coordinate system is changed. For example, the equations that establish a correspondence between the rectangular and polar coordinate systems constitute a transformation. In analysis , a transformation is a procedure that changes one function into another. Of special interest in many fields of mathematics are transformations forming a group, in which any two transformations applied successively produce the same result as another transformation in the group and each transformation has an inverse transformation (which undoes it) in the group. See also group theory , integral transform , linear transformation .