Identity Matrix

An Identity Matrix is a square boolean matrix with 1s along the matrix diagonal.

• • …
• Example(s):
  • [math]\displaystyle{ \begin{bmatrix} 1 & 0\\0 & 1 \end{bmatrix} }[/math]
• Counter-Example(s):
  • a Zero Matrix.
• See: Identity Vector.

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References

2011

• http://en.wikipedia.org/wiki/Identity_matrix
  • QUOTE: In linear algebra, the 'identity matrix or unit matrix of size n is the n×n square matrix with ones on the main diagonal and zeros elsewhere. It is denoted by In, or simply by I if the size is immaterial or can be trivially determined by the context. (In some fields, such as quantum mechanics, the identity matrix is denoted by a boldface one, 1 ; otherwise it is identical to I.) [math]\displaystyle{ I_1 = \begin{bmatrix} 1 \end{bmatrix} ,\ I_2 = \begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix} ,\ I_3 = \begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix} ,\ \cdots ,\ I_n = \begin{bmatrix} 1 & 0 & \cdots & 0 \\ 0 & 1 & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\ 0 & 0 & \cdots & 1 \end{bmatrix} }[/math]

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