Add space in chart in circular mode

Hello Dear friends.
I am working with charts in circular mode. I am looking for adding some space between the recent data and the oldest data. Now it does stick them together. What should I do to achieve this?

By which I mean to hide 3 to 5 old data and hide them away.

I was thinking about adding such feature but haven’t done yet. You can do it by manually pre-deleting some points.

Just get the the array of the values with lv_chart_get_y_array(chart, ser1), set a point’s value and also set the next 3 or 5 values to LV_CHART_POINT_NONE to add a gap.

So how can one get which place is the current pointing place (index) of the chart for the next value? It would get the array, but it is also important to know which place is, so one can change the value by hand.

So after some thinking, I think you meant that to not use the lv_chart_set_next_value and use the lv_chart_set_ext_y_array?

I’ve added an example, see here: https://github.com/lvgl/lvgl/pull/2565

Thank you,
It’s helpful but it seems it needs more effort.

It’s helpful but it seems it needs more effort.

Is the “more effort” related to “gap”? If so, please let us know. Others may have the same questions.

@kisvegabor I’ve faced some issues and trying to find the source. It may have happend on my side, so when I got assured of the source of the problem, I would notify here.
The problem I have encountered is that in some cases it tries to tie the current point to some points on the grid lines.

Dear @kisvegabor
I know this is an old issue but I have found the symptom, I don’t know if it is due to the origin or if it relies on the way I used the widget. Speaking about “line type chart” in circular mode, following the code in https://github.com/lvgl/lvgl/blob/master/examples/widgets/chart/lv_example_chart_9.c,
if the space between points is considerable, for example about 10 points, the “very old” point of the chart which will be updated by the next update command, tries to stick the newest data inserted into the graph. In this case, the graph ignores that the previous data in the chart is None, but would stick to the data that is not None.

Sorry, I don’t really what the problem is :sweat_smile:

Can you send a code snippet to show the issue?