Matrices and Matrix Manipulation

Elementary Matrices

```----------------------------------------------------------------------
Elementary Matrices
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eye             Identity matrix.
gallery         Test matrices - matrix condition and eigenvalues.
linspace        Linearly spaced vector.
logspace        Logarithmically spaced vector.
meshgrid        X and Y arrays for 3-D plots.
ones            Ones matrix.
rand            Uniformly distributed random numbers.
randn           Normally distributed random numbers.
zeros           Zeros matrix.
:               Regularly spaced vector.
----------------------------------------------------------------------
```
```---------------------------------------------------------------------
Special Variables and Constants
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computer        Computer type.
eps             Floating-point relative accuracy.
flops           Count of floating-point operations.
i, j            Imaginary unit.
inf             Infinity.
NaN             Not-a-Number.
nargin          Number of function input arguments.
nargout         Number of function output arguments.
pi              3.1415926535897....
realmax         Largest floating-point number.
realmin         Smallest floating-point number
---------------------------------------------------------------------
```
```------------------------------------------
Time and Dates
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clock           Wall clock.
cputime         Elapsed CPU time.
date            Calendar.
etime           Elapsed time function.
tic, toc        Stopwatch timer functions.
------------------------------------------
```
```-------------------------------------------------------------------
Matrix Manipulation
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diag            Create or extract diagonals.
fliplr          Flip matrix in the left/right direction.
flipud          Flip matrix in the up/down direction.
isreal          True for matrix containing real elements only.
reshape         Change size.
rot90           Rotate matrix 90 degrees.
tril            Extract lower triangular part.
triu            Extract upper triangular part.
:               Index into matrix, rearrange matrix.
-------------------------------------------------------------------
```

Specialized Matrices

```----------------------------------------------------------------
Specialized Matrices
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compan           Companion matrix.