DISTANCE BETWEEN ANY TWO PLACES

Hey guys,

Im pretty new to matlab and am having quite some trouble with a question iv been given at uni. The question wants me to create a user friendly interface which allows users to calculate the distance between any two cities in australia.

I found a link online about how to do this by entering the co ordinates (>distdim(distance(53.9, 27.5667, 10.5207, -66.9245),'deg','kilometers') however this doesn't really help me as it isnt very user friendly to require the user to type in his own co ordinates.

If someone could please help me with this it would be greatly appreciated.

[Image Analyst]

Do you have the mapping toolbox? (If so, add it to the Products below.)

Answer 1

[Andrei Bobrov]

use Mapping Toolbox

Create data with coordinates of citys of Australia.

eg

global coord_citys_aus;

coord_citys_aus = {'Adelaida', -34.899448, 138.589783
          'Brisbane', -27.452228, 153.039551
          'Canberra', -35.308401, 149.124298
          'Perth',    -31.932351, 115.861816
          'Darwin',   -12.462789, 130.841739}
save('coord_citys_aus.mat','coord_citys_aus');

% Your function

function out = myauscitysdist(namefirstcity,namesecondcity)
global coord_citys_aus;
indat = coord_citys_aus(ismember(coord_citys_aus(:,1),...
                                            {namefirstcity,namesecondcity}),2:3)';
out = deg2km(distance(indat{:}));

% Example use

>> load coord_citys_aus.mat;
>> out = myauscitysdist('Perth','Brisbane')
out =
         3608

variant without use function distance from Mapping Toolbox

function out = distbetweencitysAustrig0(namescity)
global citys_Aus;
    [~,i0] = ismember(namescity,citys_Aus(:,1));
    jj = nchoosek(1:numel(namescity),2);
    d = cell2mat(reshape(citys_Aus(i0(jj),2),[],1,2));
    p = cosd(d(:,1,:));
    x2 = sum(p.^2,3) - 2*prod(p,3).*cosd(diff(d(:,2,:),1,3));
    y2 = diff(sind(d(:,1,:)),1,3).^2;
    out = 12742*asin(sqrt(x2 + y2)/2);    
end

and example use function distbetweencitysAustrig0

>> global citys_Aus;
load('citys_Aus.mat');
>> namescity = {'Adelaide';'Darwin';'Sydney';};
>> out = distbetweencitysAustrig0(namescity)
out =
       2617.6
       1161.9
       3148.6