## FLIPUD Reverse the Columns of a Matrix

Section: Array Generation and Manipulations

### USAGE

Reverses the rows of a matrix. The syntax for its use is

       y = flipud(x)

where `x` is matrix. If `x` is an N-dimensional array then the first dimension is reversed.

### Example

The following example shows `flipud` applied to a 2D matrix.

    --> x = int32(rand(4)*10)

    x =
      0  7  2  6
      5  7 10  1
      2  6  8  0
      1  0  9  8

    --> flipud(x)

    ans =
      1  0  9  8
      2  6  8  0
      5  7 10  1
      0  7  2  6

For a 3D array, note how the rows in each slice are flipped.

    --> x = int32(rand(4,4,3)*10)

    x =

    (:,:,1) =
      8  4  6  7
      6  0  7  6
      8  9  9  0
      1  2 10  5

    (:,:,2) =
      9  6  2  8
      3 10  1  7
      6 10  9  8
      3  2  4  2

    (:,:,3) =
      3  1  5  0
      0  6  5  1
      9  4  9  2
      6 10  8 10

    --> flipud(x)

    ans =

    (:,:,1) =
      1  2 10  5
      8  9  9  0
      6  0  7  6
      8  4  6  7

    (:,:,2) =
      3  2  4  2
      6 10  9  8
      3 10  1  7
      9  6  2  8

    (:,:,3) =
      6 10  8 10
      9  4  9  2
      0  6  5  1
      3  1  5  0