compute iterations to calculate pairs of data that do not repeat

Hi there I have 15 sets of x,y,z data points. I want to compute 105 possible combinations of these points using a computational method. I believe I will want to use a loop although I am not sure how to set one up that discards any repeating combinations.

This is the code I have:

% script to caluclate the correlation dimension of points 

% with delta[log N_D (R)] / delta (log R) ( taken from Kagan.Y (2007)
% Earthquake spacial distribution: The correlation dimension. 
% where 
% D = dimensionality = 3-D 
% N = total number of earthquake pairs = n(n-1)/2
% R = distance between points = sqrt((x2-x1)^2 + (y2-y1)^2 + (z2-z1)^2)

N = 15*(15-1)/2 %the number of pairs I can have 

% The Data set (15 points) 
x_vals=[-9.33203	-9.92969	-9.40234	-9.47266	-8.83984	-9.50781	-10.0703	-9.08594	-9.50781	-10.0352	-9.12109	-9.05078	-9.26172	-9.82422	-10.3516];
y_vals=[27.8633	27.6172	27.6523	27.5117	27.9336	27.6172	27.3359	27.6172	27.6172	27.2305	27.9336	28.0039	27.793	27.7227	26.7734];
z_vals=[10.0098	8.04297	8.97461	7.98086	9.51289	8.04297	10.1133	10.0305	7.96016	7.98086	9.47148	7.77383	8.76758	9.34727	7.79453];

Any help would be much appreciated!

Answer 1

[KSSV]

Read about nchoosek

https://in.mathworks.com/help/matlab/ref/nchoosek.html

[P_L]

Hi KSSV thank you for getting back to me. Do you know how to specify the v in the example : C=nchoosek(v,k) given that I have x,y and z data for each data point?

I need the combination of data points.

Many thanks

[KSSV]

LEt x,y,z be your data

xi = nchoosek(x,2) ; 

[P_L]

Hi KSSV I don't understand, please could you explain more clearly? I need combinations of x,y and z data.

Many thanks