How to find nearest two points each other ?
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Hi Everyone,
I have
X = (Yt.*sin(W))-(Xt.*cos(W));
Y = (Yt.*cos(W))+(Xt.*sin(W)); which give the coordinates X and Y.
X_inv = R.*sin(B_involute);
Y_inv = R.*cos(B_involute); which give the coordinates X_inv and Y_inv.
I need to find the nearest two points between X,Y and X_inv,Y_inv.
lots of thanks from now.
2 个评论
Image Analyst
2015-11-29
What is W? What is B_involute? Can you post a diagram or plot of this and point out X, Y, X_inv, Y_inv what two points on there you'd like to have it return - which are the "two points"? And it's ambiguous. What's nearest to what? Two points nearest to each other? Two points nearest to either X,Y or X_inv,Yinv? For example if you have 2,6,7,50, then 6 and 7 are nearest to each other but 6 and 7 are closer to 2 than they are to 50, so would you return 6 and 7, or return 2???
采纳的回答
Star Strider
2015-11-29
If you have the Statistics Toolbox, use the pdist2 function.
4 个评论
Star Strider
2015-11-29
编辑:Star Strider
2015-11-29
My pleasure!
You would simply use your ‘X’, ‘Y’, ‘X_inv’ and ‘Y_inv’ in my code, eliminating the lines I used to create them to test it.
You would use only:
for k1 = 1:length(X)
for k2 = 1:length(X_inv)
DE(k1,k2) = hypot(X(k1)-X_inv(k2), Y(k1)-Y_inv(k2)); % Euclidean Distance
end
end
[DEmin,ix] = min(DE(:));
[K1,K2] = ind2sub(size(DE),ix);
fprintf(1,'\nNearest Points:\n\tDistance = %.3f\n', DEmin)
fprintf(1,'\t\tX(%d), Y(%d) \t\t\t= %.2f, %.2f\n', K1, K1, X(K1), Y(K1))
fprintf(1,'\t\tX_inv(%d), Y_inv(%d) \t= %.2f, %.2f\n', K2, K2, X_inv(K2), Y_inv(K2))
更多回答(2 个)
Image Analyst
2015-11-29
Use a nested for loop and the sqrt() function, then sort() and find() to find the 8 closest distances at the two points where your curves intersect.
Or maybe you could use roots(curve1-curve2).
Semion
2020-4-14
Hi. Could you explain, how does method "dsearchn" select an index of multi closest points with the same distance to target point? BW, the method "dnsearch" with and without triangulation produce different results.
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