Changes

Jump to navigation Jump to search
3,164 bytes removed ,  19:42, October 15, 2009
m
Replaced content with 'Did you take the red pill or the blue pill?'
Line 1: Line 1: −
''For the 1999 film, see [[The Matrix]].''
+
Did you take the red pill or the blue pill?
−
 
  −
A '''matrix''' (pl.: "matrices," [[Latin]] origin) is a complex ordering, in deliberate fashion, of [[numeral|numerals]].  In [[mathematics]], a "matrix" is a regular grid of numbers, which may be manipulated and solved through intermediate-level [[algebra]].  Matrix algebra is usually taught in [[sophomore]] [[high school]] level mathematics.
  −
 
  −
More formally, a matrix is an example of a rank-2 [[tensor]].
  −
 
  −
Alternately, a '''matrix''' may also be a complex ordering of a group of equivalent objects, especially where the order is imposed to gain incidental benefit from the [[synergy]] of the networked objects.
  −
 
  −
==Mathematics==
  −
In mathematics, matrices can be manipulated in a variety of ways, including [[addition]] and [[multiplication]].
  −
 
  −
===Addition of matrices===
  −
For example, to add two matrices, one would add their respective elements, thus:
  −
 
  −
<math>\begin{bmatrix}
  −
  x      & y & z      \\
  −
  1 & 3 & 5 \\
  −
  0      & 2 & 0
  −
\end{bmatrix} + \begin{bmatrix}
  −
  0      & 3 & 1      \\
  −
  4 & 3 & {x+2} \\
  −
  0      & 4 & v
  −
\end{bmatrix} </math>
  −
 
  −
would equal
  −
 
  −
<math>\begin{bmatrix}
  −
{x+0} & {y+3} & {z+1} \\
  −
{1+4} & {3+3} & {5+(x+2)} \\
  −
{0+0} & {2+4} & {0+v}
  −
\end{bmatrix} = \begin{bmatrix}
  −
x & {y+3} & {z+1} \\
  −
5 & 6 & {x+7} \\
  −
0 & 6 & v
  −
\end{bmatrix} </math>
  −
 
  −
===Multiplication of matrices===
  −
To multiply two matrices, one uses the rule "go along the rows and down the columns". This is best illustrated by a specific example: a matrix times a vector:
  −
 
  −
<math>\begin{bmatrix}
  −
a & b \\
  −
c & d
  −
\end{bmatrix} \begin{bmatrix}
  −
e \\ f
  −
\end{bmatrix}=\begin{bmatrix}
  −
ae+bf \\
  −
ce+df \end{bmatrix}
  −
</math>
  −
 
  −
It is important to note that matrix multiplication is not commutative: in general, <math>AB \neq BA</math> for two matrices <math>A</math> and <math>B</math>. This has important consequences in [[quantum mechanics]].
  −
 
  −
To see why matrix multiplication works the way it does, we will use [[suffix notation]]. Consider first forming the product of two matrices, <math>AB</math>, which is itself a matrix. Then form the product <math>ABx</math>. Matrix multiplication is associative, so we can consider this as either <math>(AB)x</math> or <math>A(Bx)</math>. In suffix notation,
  −
 
  −
<math>
  −
\sum_j(AB)_{ij}x_j = \sum_k A_{ik}(Bx)_k=\sum_{j,k}A_{ik}B_{kj}x_j
  −
</math>
  −
The vector <math>x</math> is arbitrary, so we can therefore deduce the rule for finding the product of two matrices:
  −
 
  −
<math>
  −
(AB)_{ij}=\sum_k A_{ik}B_{kj}
  −
</math>
  −
 
  −
===Matrix concepts===
  −
 
  −
====Basic concepts====
  −
 
  −
*[[Adjoint]]
  −
*[[Determinant]]
  −
*[[Diagonal matrix]]
  −
*[[Identity matrix]]
  −
*[[Inverse matrix]]
  −
*[[Null, column and row space]]
  −
*[[Scalar]]
  −
*[[Trace]]
  −
*[[Transpose matrix]]
  −
*[[Vector]]
  −
*[[Zero matrix]]
  −
 
  −
====Advanced concepts====
  −
 
  −
*[[Basis]]
  −
*[[Diagonalizeable]]
  −
*[[Eigenspace]]
  −
*[[Eigenvalue]]
  −
*[[Eigenvector]]
  −
*[[Gram-Schmidt process]]
  −
*[[Hermitian matrix]]
  −
*[[Jordan canonical form]]
  −
*[[Laplacian]]
  −
*[[Linear independence]]
  −
*[[Matrix diagonalization]]
  −
*[[Matrix reformation]]
  −
*[[Matrix transformation]]
  −
*[[Orthogonal matrix]]
  −
*[[Orthonormal matrix]]
  −
*[[Resultant]]
  −
*[[Span]]
  −
*[[Systems of linear equations]]
  −
*[[Transcriptor]]
  −
*[[Wronskian]]
  −
 
  −
[[Category:Linear algebra]]
  −
[[Category:Computers]]
 

Navigation menu