Customed distance function Haversine
조회 수: 13 (최근 30일)
이전 댓글 표시
Miguel Angel Sanchez Aportela
2021년 6월 9일
댓글: Scott MacKenzie
2021년 7월 13일
For a proyect I want to use pdist2 (Pairwise distance between two sets of observations) but I need an specific function.
I have two data sets of different sizes, one of which is a nx2 matrix of latitude, longitude.
I'm trying to calculate Haversine distance but I don't know how to apply the funtion in this case. Would you help correcting my function? Thank you in advance.
axa = pdist2(latlon1(:, 1:2), latlon2(:, 1:2), @haversine);
function [dist] = haversine(lat1,lon1,lat2,lon2)
dist = 2 * 6372.8 * asin(sqrt(sind((lat2-lat1)/2)^2 + cosd(lat1) * cosd(lat2) * sind((lon2 - lon1)/2)^2));
end
댓글 수: 1
SALAH ALRABEEI
2021년 6월 21일
pdist2 has only three metric distances ( 'seuclidean', 'minkowski', or 'mahalanobis').
So since your lon and lat are not of the same length; you can create grid
[x,y]=meshgrid(lon,lat);
채택된 답변
Scott MacKenzie
2021년 6월 21일
편집: Scott MacKenzie
2021년 6월 26일
You need to re-work your haversine function, as per the requirements for distance functions used with pdist2. A custom distance function for pdist2 needs two input arguments and the first must specify just a single observation:
axa = pdist2(latlon1(1, 1:2), latlon2(:, 1:2), @haversine); % repeat for other values in latlon1
function [dist] = haversine(ZI, ZJ)
lat1 = ZI(1,1);
lon1 = ZI(1,2);
lat2 = ZJ(:,1);
lon2 = ZJ(:,2);
dist = 2 * 6372.8 * asin(sqrt(sind((lat2-lat1)/2)^2 + cosd(lat1) * cosd(lat2) * sind((lon2 - lon1)/2)^2));
end
댓글 수: 2
Scott MacKenzie
2021년 7월 13일
@Miguel Angel Sanchez Aportela You're welcome. Glad to help. Good luck with your research.
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Statistics and Machine Learning Toolbox에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!