How to extract the scatter data based on a function

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joynjo 2018-7-18

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编辑： joynjo 2018-7-21

I have a scatter data as attached image follows, how to sign the data outside the function line with '1' and the data under the function line with '0' then save it into one variable?

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joynjo 2018-7-21

Up, I am still waiting for anyone who can help me solve this problem, thanks

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Image Analyst 2018-7-18

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I have no idea what "sign the data" with 0 or 1 means, but to get the data under and above/outside the function, try something like this

indexesUnderTheCurve = false(1, length(x));
for k = 1 : length(x)
  thisX = x(k);
  thisY = y(k);
  curveY = YourFunction(thisX); % Plug the x into your custom function
  if thisY < curveY
    % Under the curve
    indexesUnderTheCurve(k) = true;
  end
end
xUnder = x(indexesUnderTheCurve);
yUnder = y(indexesUnderTheCurve);
xOver = x(~indexesUnderTheCurve);
yOver = y(~indexesUnderTheCurve);