Graphics on Android: path with smooth curves?

Question

I want to draw a chart for a function y=x^2 as follows:

enter image description here

but the curve is not smooth as it is a set of connected lines.

how can I make the curve smoother ?

thanks

Che Jami · Accepted Answer · 2011-08-15T14:06:27.750

9

You should use Path.quadTo with only one Path. If you are already doing this then I suggest increasing the number of points on the graph.

Move to the beginning of the Path:

Path.moveTo(x, y)

in the middle:

Path.quadTo(lastX, lastY, (x + lastX)/2, (y + lastY)/2)

and at the end:

Path.lineTo(x, y)

edited Aug 15 '11 at 14:06

answered Aug 15 '11 at 13:51

Che Jami

I'm using Path.lineTo(), does increasing the points solve the problem ? – Mina Wissa Aug 15 '11 at 13:53
1

Path.quadTo() should be enough and should look significantly better than lineTo() when it comes to curves. – Che Jami Aug 15 '11 at 13:53
It's the same, maybe if I increased the points it will get better – Mina Wissa Aug 15 '11 at 13:57
Don't do that yet. There should be a *signficant* difference. Are you sure you are using it properly? Wait let me write something up. – Che Jami Aug 15 '11 at 14:00
Yes but it will effect performance, try using the updated answer - it will create the same effect. – Che Jami Aug 15 '11 at 14:08
1

Thanks a lot, I tried your method of plotting and it worked great, no need to add extra points. – Mina Wissa Aug 16 '11 at 08:40
Compare to http://stackoverflow.com/a/13227841/901597 which employs lineTo in the first segment. – Joe Bowbeer Mar 02 '13 at 03:55

1 Answers1