How can I don't draw lines when data absent at some point?

[willard1218]

If I have frequently data, but sometimes data absent at some point.
For example:

The interval of the dataset are same, in this case is 1.
So the data absent at x = 5, 6.

How can I don't draw line between x = 4 and x = 7 ?
Just like this:

[liuxuan30]

create two data sets for each line segment.

[willard1218]

If I have data at these point:
x = 0, 1, 2
x = 4, 5
x = 8, 9

So the data absent at x = 3, 7

then I have to create three data sets?

[liuxuan30]

I'm afraid so. one set for one line segment. I used to add this feature, however it's kind of buggy when thinking about filling beneath line area, so the workaround is use multiple data sets so far.

if you don't need filling, that's easier you can just override drawLinear to add those break points. warning: you have to fully understand how it works and then you know how to break the lines.

[willard1218]

Finally, I modify the LineChartRenderer.swift,
here is the change

I define data not existed if y == -999,
So, when y = -999, I just move(to: pt) instead of addLine(to: pt).

Here is result

The dataSet of Heartbeat are [80,90,-999,80,68,-999,-999,95]

[liuxuan30]

you can use NSNotFound instead of -999. have you tested both positive values and negative values together? As I said, evil in the filling part.
but if it's always positive values like bpm, it should be fine for your case.

[willard1218]

Yes, i will use NSNotFound instead of -999, and my dataset are always positive values.
As you said, when I fill the chart.

the green area has fill color, but I don't want this.
So this is a problem...