IOS-Charts Adjust circle radius for individual line chart data point - swift

Question

I'm using iOS-Charts linechart view to draw lines that have zero circle radius and I would like the user to be able to drop Points on the line. Is there a way to change an individual data points circle radius from zero to 20 by using the delegate chartValueSelected?
I can easily change the entire dataSet circleRadius, but I'm having a hard time figuring out how to do individual data points.
lineChartDataSet2.circleRadius = 0
lineChartDataSet2.circleRadius = 20

Answer 1

I solved this in an application by actually having multiple data sets, the second data set being used only for adding points on the same line but with a given circle radius. I checked with the developers of Charts and there's no other way to achieve it.
I have:
- (void)displayChartWithSet:(LineChartDataSet *)set highlightedSet:(LineChartDataSet *)highlightedSet {
set.drawValuesEnabled = NO;
set.drawCirclesEnabled = YES;
set.circleColors = [NSArray arrayWithObject:[UIColor clearColor]];
set.colors = [NSArray arrayWithObject:[UIColor whiteColor]];
set.lineWidth = 2.0f;
set.mode = LineChartModeHorizontalBezier;
//Builds the data to be presented from two distinct data sets
// one containing only points with a radius
LineChartData *data = [[LineChartData alloc] initWithDataSets:[NSArray arrayWithObjects:set, highlightedSet, nil]];
}
This allows me to add individual points to the highlighted set and then redraw the view when needed, or have a nil set and have no highlighted points. There's a further setup function for the highlighted data set that does the configuration of points.