Curve fitting of data points
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I have a series of repeated data points that i am trying to fit with a skewed curve. In the graph I am showing one set of the data points which are in blue. The black hand drawn line is the kind of fit i want for my data. I want my fit to be a curve like the one drawn, not a combination of two linear functions or a sawtooth. I have included the data points in text files. Thank you.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/192206/image.jpeg)
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Walter Roberson
2018-7-19
编辑:Walter Roberson
2018-7-19
That may be true for the input data, but the black line you show us as the desired fit distinctly wobbles back and forth on the x axis, and since that is presented as your desired outcome, the implication could be that you want the output function to have multiple y values for some of the x.
Anyhow... so if a sharp corner is not desired, then what turn radius should be used?
Do you have a model for what you want the function to be like?
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Matt J
2018-7-19
3 个评论
Matt J
2018-7-20
编辑:Matt J
2018-7-20
You are only interested in the positive portion of the hyperbola, so you can write that portion as,
y=a*sqrt(1+(x/b)^2);
which will be like the green curve in the image below. You can also rotate your input x,y data about 135 degrees counter-clockwise so that it will also have a corresponding profile like the red lines in the image below.
Now everything is oriented in a familiar way.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/192458/image.png)
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Walter Roberson
2018-7-19
Have you considered smoothing splines? https://www.mathworks.com/help/curvefit/smoothing-splines.html
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