Function pdist and knnsearch

Question

I have implemented this KNN inner distance equation for the output of the knnsearch function.

Example

Main dataset is `{ 1 ;2; 5; 10; 20 }`                                          
Query dataset is `{ 3 }`                                                                                               
calculate the distance for all point                                 
k=3
Discard 3-3=0                                                                                              
3-1=2                                                                        
3-2=1                                                                             
3-5=2                                                      
3-10=7                                                                             
3-20=17                                                                        
so {1;2;5} will be nearest neighbours for 3                                          
to calculate knn in  the equation  

  Matrix point
      p  1 2 5                                                                                                                                                                                                                                  
      1  0 1 4                                                                       
      2  1 0 3                                                                    
      5  4 3 0                                                                      
calculate knn-inner distance= (1+4+1+3+4+3)/6

                                            

My code is part of LDOF outlier algorithm when I checked my code, I found this part not accurate for a multidimensional array. This is the first time using pdist function, I have used it for speed.

[Idx,Dist] = knnsearch(main,query,'k',10); 
    
sizedata=size(Idx)
        
Dxp=mean(pdist(main(Idx(1,2:end),:)));
for m =2 : sizedata
    d=Dxp;        
    Dxp=mean(pdist(main(Idx(m,2:end),:)));
    % to make matrix with all knn-inner distance for all query points
    Dxp=[d;Dxp];
end

I have Matlab 2018.