Mahalanobis distance: What if S is not invertible?
29579
Ways to measure distance from multivariate Gaussian (Mahalanobis distance)
37653
Singular covariance matrix in Mahalanobis distance in Matlab
130268
How to prove that a nilpotent matrix is not invertible?
26493
Prove the relation between Mahalanobis distance and Leverage?
55259
ArcTan[z] and ArcTan[x,y], Restriction and Conversion
137881
A not complete metric space?
19219
On the invertibility of the adjacency matrix of a graph
20583
Strange distance measurements in distance matrix
155272
Is a matrix with $1$s in the diagonal and off-diagonal entries with absolute value less than $1$ invertible?
18585
Showing $A-I$ is invertible, when $A$ is a skew-symmetric matrix
25874
Showing that a certain map is not flat by explicit counterexample
42467
Inverse of an invertible triangular matrix (either upper or lower) is triangular of the same kind
15417
Tricky problem on skew-symmetric matrices
140124
The distance function on a metric space
127052
Independence of non-constant real variables
157572
The distance between two sets inside euclidean space
141286
When is $\mathbf{X}^{T}\mathbf{X}+\lambda\mathbf{I}$ invertible?