Selecting the nearest data point in a 2-D plot

Hi,

Is it possible to select the nearest data point rather select any point on the graph? I have seen "ginput" and "getpts" function. Both of these select the point that we click not the nearest data point.

For example you can view thw bottom code

x = 0:0.1:10;

for C=1:3
    za = C;
y = (x.^za);
hg = figure(1);
plot(x,y);hold on;
[xda(:,C),yda(:,C)] = ginput(2);
%[xda(:,C),yda(:,C)] = getpts(hg);
display(za);
end

Answer 1

[Ajay Kumar]

Try to perform difference (and take minimum of absolute) between both ginput data point and original data and take out the index.

[val,idx]=min(abs(ginput_data - original_data));

then use this idx to go to the original data (which is the nearest point) instead of any point on axes.

[darova]

Using difference you just find min(dx) and min(dy). Use minimum distance instead (e.g. pdist2)

[Ajay Kumar]

Also, a small addition to darova's comment. pdist2 needs Statistcs and machine learning toolbox.