Calculate mahalanobis distance of matrix for each row

I want to calculate mahalanobis distance of matrix A for each row with respect to average value of column.

I use 'mahal' function in matlab

A = [110 -100 0; 100 -100 0; 10 0 0; 0 10 0; 0 -10 20; 0 -10 10; 0 0 10;-10 -10 -10; -10 0 0];
mean_row = mean(A,1);
mahal(mean_row,A) 

But it gives zero value.

The result should be:

MD = [2.0937; 1.9970; 0.9072; 0.9517; 2.2387; 1.3394; 1.0792; 2.2596;0.9072]

Answer 1

[Chunru]

A = [110 -100 0; 100 -100 0; 10 0 0; 0 10 0; 0 -10 20; 0 -10 10; 0 0 10;-10 -10 -10; -10 0 0];
mean_row = mean(A,1);
whos

  Name          Size            Bytes  Class     Attributes

  A             9x3               216  double              
  mean_row      1x3                24  double              

d =  pdist2(A, mean_row, 'mahalanobis')

d = 9×1

1.8757 1.7646 1.5110 1.6756 2.0319 1.0264 0.9549 2.2982 0.9496

[NA]

I checked out other data set and found that the result is different from the code.

I have this data set:

A = [10 -10; 1 0; -1 0; 0 -1; 0 1 ;11 -10; -1 -1]

The Mahalanobis distance that I got from your code is

1.4725
1.2957
0.83996
0.74575
1.4513
1.5646
1.5287

but the actual result is

I do not understand why I could get same result.

I mean, same thing happens for this data set

A = [110 -100 0; 100 -100 0; 10 0 0; 0 10 0; 0 -10 20; 0 -10 10; 0 0 10;-10 -10 -10; -10 0 0];

the result should be

But I got different result.