MAHALAN

Computes Mahalanobis distance.



 Synopsis:
  dist = mahalan(X,Mean,Cov)

 Description:
  It computes Mahalanobis distance between column vectors 
  of matrix X and vector Mean with matrix Cov, i.e.,

    dist(i) = (X(:,i)-Mean)'*inv(C)*(X(:,i)-Mean)

  for all i=1:size(X,2).

 Input:
  X [dim x num_data] Input data.
  Mean [dim x 1] Vector.
  Cov [dim x dim] Matrix.

 Output:
  dist [1 x num_data] Mahalanobis distance.

 Example:
  It plots isolines of Mahalanobis distance.

  [Ax,Ay] = meshgrid(linspace(-5,5,100), linspace(-5,5,100));
  dist = mahalan([Ax(:)';Ay(:)'],[0;0],[1 0.5; 0.5 1]);
  figure; contour( Ax, Ay, reshape(dist,100,100));


Source: mahalan.m

About: Statistical Pattern Recognition Toolbox
(C) 1999-2003, Written by Vojtech Franc and Vaclav Hlavac
Czech Technical University Prague
Faculty of Electrical Engineering
Center for Machine Perception

Modifications:
28-apr-2004, VF