Azzera filtri
Azzera filtri

Reasons for shorter distance calculated by 'distance'?

2 visualizzazioni (ultimi 30 giorni)
Ali Y.
Ali Y. il 17 Lug 2015
Modificato: bizhan il 27 Lug 2015
What would be the reason for shorter distance calculated by the following code?
clc
X = [ 45.1612 ; 45.1585 ; 45.1252 ; 45.0853 ];
Y = [ 38.3228 ; 38.3749 ; 38.4162 ; 38.4516 ];
E = wgs84Ellipsoid('km');
for i = 2:numel(X)
[dis, az] = distance( Y(i-1), X(i-1), Y(i), X(i), E, 'degrees');
end
dis = cumsum(dis);
az = mean(az);
disp([dis, az])
I have an arched line of length 16.603506 km, calculated in 'ArcMap'. X and Y are coordinates of vertices of the line, so that, X(1) and Y(1) are the coordinate of first (starting) vertex and X(end) and Y(end) are those of last (ending) vertex. According to the code the distance between starting and ending vertices on the line is 15.7603 km. My question is where of the code is wrong that cause this discrepancy? Note: Total number of vertices of the line is 289 and the distance between starting and ending vertices are 15.7688 km. Any help is appreciated. Thank you in advance for your help.

Risposte (1)

bizhan
bizhan il 27 Lug 2015
Modificato: bizhan il 27 Lug 2015
I tried the havesine formulas to calculate the spherical distance and the result is 15.78 the same as the "distance" function. I think both are using spherical or eliptical earth assumption. for better and more accurate solutions, local geoid assumption and formulas will be necessary.

Categorie

Scopri di più su Computational Geometry in Help Center e File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by