FreeMat
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 = 
 9 4 5 3 
 8 9 7 4 
 4 8 6 3 
 6 7 0 9 

--> flipud(x)

ans = 
 6 7 0 9 
 4 8 6 3 
 8 9 7 4 
 9 4 5 3 

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

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

x = 

(:,:,1) = 
  7  4  3  3 
  0 10 10  6 
  2  8  1  8 
  1  1  9  8 

(:,:,2) = 
  4  4  3  2 
  4  4  7  1 
  4  9  9  8 
  5  5  1  6 

(:,:,3) = 
  9  7  7  5 
  8  9  5  6 
  5 10  6  8 
  4  2  8  3 

--> flipud(x)

ans = 

(:,:,1) = 
  1  1  9  8 
  2  8  1  8 
  0 10 10  6 
  7  4  3  3 

(:,:,2) = 
  5  5  1  6 
  4  9  9  8 
  4  4  7  1 
  4  4  3  2 

(:,:,3) = 
  4  2  8  3 
  5 10  6  8 
  8  9  5  6 
  9  7  7  5