Mathematics    

The Identity Matrix

Generally accepted mathematical notation uses the capital letter to denote identity matrices, matrices of various sizes with ones on the main diagonal and zeros elsewhere. These matrices have the property that and whenever the dimensions are compatible. The original version of MATLAB could not use for this purpose because it did not distinguish between upper and lowercase letters and already served double duty as a subscript and as the complex unit. So an English language pun was introduced. The function

returns an m-by-n rectangular identity matrix and eye(n) returns an n-by-n square identity matrix.


  Matrix Multiplication The Kronecker Tensor Product