Mahalanobis distance between two vectors?

I want to calculate distance between two vector using Mahalanobis distance. Suppose, A=[2 3 4 5] and B=[4 5 6 7] How can I calculate Mahalanobis distance between the two vector? Is it possible like euclidean distance? Any one help me please. They make me confusion!!

[Adam]

You need a covariance matrix in order to calculate mahalanobis distance as it is a distance relative to a system where a unit distance is effectively the surface of a hypersphere of some orientation or other often represented by some statistical model.

[K M Ibrahim Khalilullah]

Thank you very much. How can I get covariance matrix from the vector?

Answer 1

[John D'Errico]

help pdist

[K M Ibrahim Khalilullah]

Thanks John D'Errico for your reply. In pdist like D = pdist(X) Only X. but how can I arrange A and B into X? Please explain..