[R] vectorization instead of using loop

Dear all, I've sent this question 2 days ago and got response from Sarah. Thanks for that. But unfortunately, it did not really solve our problem. The main issue is that we want to use our own (manipulated) covariance matrix in the calculation of the mahalanobis distance. Does anyone know how to ve

Re: [R] vectorization of a loop for mahalanobis distance calculation

Dear all,we just realized something. Sarah's distance function - indeed - calculates mahalanobis distance very well. However, it uses the observed variance-covariance matrix by default. What we actually need (sorry for not stating it clearly in to be able to specify which variance-covariance matrix

[R] vectorization of a loop for mahalanobis distance calculation

Dear all, We have a data frame x with n people as rows and k variables as columns. Now, for each person (i.e., each row) we want to calculate a distance between him/her and EACH other person in x. In other words, we want to create a n x n matrix with distances (with zeros in the diagonal). Howeve