Reflection (mathematics) - Reflection Across A Line in The Plane

Reflection Across A Line in The Plane

Reflection across a line through the origin in two dimensions can be described by the following formula

Where v denotes the vector being reflected, l denotes any vector in the line being reflected in, and v·l denotes the dot product of v with l. Note the formula above can also be described as

Where the reflection of line l on a is equal to 2 times the projection of v on line l minus v. Reflections in a line have the eigenvalues of 1, and −1.

Read more about this topic:  Reflection (mathematics)

Famous quotes containing the words reflection, line and/or plane:

    Public morning diversions were the last dissipating habit she obtained; but when that was accomplished, her time was squandered away, the power of reflection was lost, [and] her ideas were all centered in dress, drums, routs, operas, masquerades, and every kind of public diversion. Visionary schemes of pleasure were continually present to her imagination, and her brain was whirled about by such a dizziness that she might properly be said to labor under the distemper called the vertigo.
    Sarah Fielding (1710–1768)

    This wild night, gathering the washing as if it were flowers
    animal vines twisting over the line and
    slapping my face lightly, soundless merriment
    in the gesticulations of shirtsleeves ...
    Denise Levertov (b. 1923)

    In time the scouring of wind and rain will wear down the ranges and plane off the region until it has the drab monotony of the older deserts. In the meantime—a two-million-year meantime—travelers may enjoy the cruel beauties of a desert in its youth,....
    —For the State of California, U.S. public relief program (1935-1943)