Efficiently calculate distance between moving point and fixed points

Question

T 2017-9-25

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/358255-efficiently-calculate-distance-between-moving-point-and-fixed-points

回答： Niraj Gadakari 2017-9-28

Hello,

I have a grid of point coordinates

xval=0:1:5000;
yval=0:1:2000;
zval=1;
[X,Y,Z]=meshgrid(xval,yval,zval);

to those points defined by X,Y,Z and to another point I want to calculate the distances.

mypoint=[500 700 5];
dist=sqrt( (mypoint(1)-X).^2 +  (mypoint(2)-Y).^2 +  (mypoint(3)-Z).^2 );

This gives me my distances of mypoint to my grid of points. However, mypoint is changing over time. And for each time step I need all distances. I can do this with a simple for loop, but I was wondering if there is a more efficient way if mypoint is changing over time. Thanks