Computing distance between two set of points (under vectorized approach)

1 回表示 (過去 30 日間)
SC
SC 2019 年 4 月 3 日
コメント済み: madhan ravi 2019 年 4 月 3 日
I have two matrices (two set of p-dimensional points), X1 and X2, which are n*p and m*p matrices. I want the final output Dist, whose i-j entries is the distance between row_i of X1 and row_j of X2 (i.e. inner product of the difference).
I want to do this in the vectorization way (avoid using for loop), since the actual matrix size is very big.
For p=2, the following can do the job (X1 is named as XY1 and X2 is named as XY2 in the example, since the dimension is 2 only):-
How can I do that, say for p=10? Many thanks!
function Dist=dist_matrix(XY1,XY2)
% input: both XY1 and XY2 have 2 columns
% input: XY1 and XY2 are not necessarily having same number of rows
X1=XY1(:,1);
Y1=XY1(:,2);
X2=XY2(:,1);
Y2=XY2(:,2);
f = @(hori,verti)(hori-verti);
Dist_X = bsxfun(f,X2',X1);
Dist_Y = bsxfun(f,Y2',Y1);
Dist=sqrt(Dist_X.^2+Dist_Y.^2);
end
  3 件のコメント
SC
SC 2019 年 4 月 3 日
Thanks for your reply. But what's your exact meaning? For example, how to do the arithmetic operations directly for the below example?
A = [8; 17; 20; 24];
B = [0 10 21];
bsxfun(@(x,y)x+y,A,B)

サインインしてコメントする。

回答 (0 件)

カテゴリ

Help Center および File ExchangeMatrix Indexing についてさらに検索

製品


リリース

R2016b

Community Treasure Hunt

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

Start Hunting!

Translated by