Smooth Spline

[plunavat]

Hello,

i want to plot a smooth spline for the points in given order
X Y
10.08378871 22.99470688
9.821493625 20.95552255
9.646630237 18.7598294
9.617486339 16.82593629
9.675774135 15.36271206
9.996357013 13.53449097
11.07468124 12.59724682
12.21129326 13.43719655
12.99817851 14.22373908
14.04735883 15.48152168
15.35883424 17.15827955
16.58287796 18.78248701

I used XYSplineRenderer for the same, but not able to do so. it gives me the following output


I want the output to something like this


Can someone help me to achieve the same

Regards,
Pranav C Lunavat

[John Matthews]

Have you tried setSeriesShapesFilled(false) or setBaseShapesVisible(false)?

[plunavat]

Thanks John for your reply. But it is not about points.
I would like to clarify more. here I am looking for the curve to be smooth and in U shape (with the given points) as shown in second image

Regards,
Pranav C Lunavat

[paradoxoff]

Looks like an artifact stemming from the interpolation between the points. The XYSplineRenderer calculates a couple of control points between adjacent data points.
Maybe you can try to use a smaller number of control points by constructing an XYSplineRenderer with a lower value for the "precision", i.e. new XYSplineRenderer(3).

[plunavat]

I have already tried using XYSplineRenderer(3) but the results are more or less same. just a bit of smoothness increases that it

Regards,
Pranav C Lunavat

[paradoxoff]

And what settings have you used to produce the chart from the image?
Looking closer at the chart, it seems that there is only one control point. If using 3 control points makes the curve smoother, then maybe using 5 or 10 control points is the way to go?

[plunavat]

i have tried this with as many possible options, but not giving desired results.

May be XYSmoothLineAndShapeRenderer() can be used which gives a better fitting curve.

But still need some logic which can generate a best fit curve for the given points

Regards,
Pranav C Lunavat

[John Matthews]

I was able to reproduce your finding by setting autoSort to false in the XYSeries used to construct the renderer. Because your data does not represent a function, you can get a somewhat better result by dividing the set into pieces that are; for example, points 1-4 and points 4-12 are pictured below. If that is not sufficient, you may want to look at other curve fitting algorithms mentioned here.

[plunavat]

Hello John,

Thanks for your feedback.
i am somehow coming very near to solve the issue.

i used XYSmoothLineAndShapeRenderer() keeping auto sort to false in XYSeries. i am getting the output as shown below



Now i have two set of data points for same curve. say Left curve and Right Curve. i want to join this curve with a spline considering the shape of left and right curve . This is shown manually by blue line(image shown below).
currently using XYSmoothLineAndShapeRenderer() this is connected as a so called straight line.


please can some one show some direction

Regards,
Pranav C Lunavat