point coordinate markers of selected points

Question

fima v 2017-3-17

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/330408-point-coordinate-markers-of-selected-points

回答： Image Analyst 2017-3-17

Hello how can i present automatickly the coordinate data marker of the selected 'or' points? Thanks

plot(x, y, 'g');
hold('on');
index = (5 < y & y < 7);
plot(find(index), y(index), 'or');

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Jan 2017-3-17

The question is not clear to me. What should happen when? What is the difference to your question https://www.mathworks.com/matlabcentral/answers/330192-marking-a-points-in-a-curve-that-match-condition? If you have problems with my answer given there, adding this as a comment would be useful.

fima v 2017-3-17

i mean showing the value of the point not only as a circle but next to it will be a small yellow window the will show the (x,y) data of this point.

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Answer 1

Image Analyst 2017-3-17

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/330408-point-coordinate-markers-of-selected-points#answer_259202

在 MATLAB Online 中打开

Try this:

numPoints = 20;
offset = 0.05; % How much away from the marker the text should be.
x = sort(rand(1, numPoints));
y = 10 * rand(1, numPoints);
plot(x, y, 'g', 'LineWidth', 2);
hold on;
index = (5 < y & y < 7);
plot(x(index), y(index), 'or', 'LineWidth', 2);
grid on;
for k = 1 : length(y)
  if index(k)
    caption = sprintf('x=%.2f, y=%.2f', x(k), y(k));
    text(x(k) + offset, y(k) + offset, caption, 'BackgroundColor', 'y');
  end
end