get the x-value of a point on curve
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I draw a curve between two vector of points, not a function, how can I get the x-value of a certain y-value of the curve?
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the cyclist
2020년 2월 20일
When you say "get", do you mean from the vectors, or only from the curve?
If you mean from the data, you can do, for example
x(y==0.25)
(You might need to be careful if y is not exactly 0.25, due to floating point precision.)
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the cyclist
2020년 2월 20일
My solution assumes the y value you are looking for is in the original vector. Sky Sartorius's solution is preferred if the y value is not in the original vector, but you want to interpolate.
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Sky Sartorius
2020년 2월 20일
This is a table lookup / interpolation problem. For your data, you'll first have to make sure there aren't any repeated y values.
yQuery = -2.6e8; % Example query point.
[Y,ind] = unique(y,'stable')
X = x(ind);
x = interp1(Y,X,yQuery)
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the cyclist
2020년 2월 20일
The best way to thank a contributor is to upvote and/or accept their answer. This rewards them with reputation points, and also directs future users to solutions.
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