%% 
% script States_distance. Read the file that contains 
% the names of the states and the lon-lat co-ordinates
% of the mid-point of each state. Compute the distance
% matrix (in km) of the states.
% It computes the pair of closest and more distant states
%
B = importdata('datafileUSA.txt');
lat =  B.data(:,1); lon =  B.data(:,2);
names = char(B.textdata)
% lon(end-7)=[]; lat(end-7)=[]; names(end-7,:)=[];
D = distances(lon,lat);
Dmin = min(min(D(D>0)))
[k,j] = find(D==Dmin)
disp(['minimum distance among states: km ' num2str(Dmin)])
disp('closest states pair: ') 
disp(names(k(1),:))
disp(names(j(1),:))
%
Dmax = max(max(D(D>0)))
[k,j] = find(D==Dmax)
disp(['maximum distance among states: km ' num2str(Dmax)])
disp('farthest states pair: ') 
disp(names(k(1),:))
disp(names(j(1),:))