What is Parallel projection?
{{jargon|date=February 2024}} [[File:Orthogonal projection.svg|frame|The transformation ''P'' is the orthogonal projection onto the line ''m''.]] In [[linear algebra]] and [[functional analysis]], a '''projection''' is a [[linear transformation]] ''P'' from a [[vector space]] to itself such that ''P''<sup>2</sup> = ''P''. Projections map the whole vector space to a [[subspace]] and leave the points in that subspace unchanged.<ref>Meyer, pp 386+387</ref> ==Notes== {{reflist}} ==References== * N. Dunford and J.T. Schwartz, ''Linear Operators, Part I: General Theory'', Interscience, 1958. * Carl D. Meyer, ''[http://www.matrixanalysis.com/ Matrix Analysis and Applied Linear Algebra]'', Society for Industrial and Applied Mathematics, 2000. {{ISBN|978-0-89871-454-8}}. ==Other websites== * [http://video.google.com/videoplay?docid=1257250980743213153 MIT Linear Algebra Lecture on Projection Matrices] {{Webarchive|url=https://web.archive.org/web/20081220071620/http://video.google.com/videoplay?docid=1257250980743213153 |date=2008-12-20 }} at Google Video, from MIT OpenCourseWare {{Math-stub}} [[Category:Linear algebra]] [[Category:Functions and mappings]]