How to write code the Chebyshev and Mahalanobis distance using bsxfun function in matlab?

Question

I found the sample code to calculate distance of two matrix using euclidean distance from here: Finding K-nearest neighbors and its implementation The data matrix are as below:

load fisheriris 
X = meas(:,3:4);
newpoints = [5 1.45; 7 2; 4 2.5; 2 3.5];

How i'm going to apply the Chebyshev and Mahalanobis distance and replace the function below:

%// Use Euclidean
dists = sqrt(sum(bsxfun(@minus, x, newpoint).^2, 2));

I tried to change the code as :

dists = max(abs(bsxfun(@minus, X, newpoint)))

The answer is as below. May be because i put the max function based on the formula.

dists2 =
      4.0000    1.3500

But, if i used this knnsearch code, it is work as expected. But i need to apply the bsxfun so that my code will be standardized with the upper codes. I want to compare the different distances in my algorithm:

[ncb,dcb] = knnsearch(X,newpoint,'k',10,'distance','chebychev')

Appreciate if anyone could help me.

Answer 1

you can find the extented version of my answer here:

https://de.mathworks.com/matlabcentral/answers/386963-how-to-write-code-the-chebyshev-and-mahalanobis-distance-using-bsxfun-function

the quintessence:

load fisheriris 
oldpoints = meas(:,3:4);
newpoints = [5 1.45; 7 2; 4 2.5; 2 3.5];
newpoints = permute(newpoints, [3,2,1]);
% Euclidean distance
dists_euclid = sqrt(sum(bsxfun(@minus, newpoints, oldpoints).^2, 2));
% Chebyshev distance
dists_cheby = max(abs(bsxfun(@minus, oldpoints, newpoints)),[],2);