Charts: ScatterViewChart entries hide when zooming

[dhhyuk]

ScatterViewChart entries hide when zooming
When scrolling the maximum item is hidden, all other items disappear.
is it have option?

[liuxuan30]

not quite understand what are you asking? a bug or you want to hide something?

[dhhyuk]

a bug.
When I scrolled after I zoomed in, some of the entries in the data set disappeared.

[liuxuan30]

can we reproduce it with ChartsDemo? It looks fine though

[dhhyuk]

before zooming.
https://drive.google.com/file/d/0B3Lv_uliEGSjWkZfUTlNT3Z5MGs/view?usp=sharing
shown all entries.

but after zooming.
https://drive.google.com/file/d/0B3Lv_uliEGSjMXoyT0lwUWU2WFU/view?usp=sharing
When the entry on the far right disappears, center entries disappears.

[liuxuan30]

ok. but we need more details then; the axis range seems not changed much. I encourage you debug on your side first.

have you checked all your data entries are there in drawDataSet? need you give a minimum reproducible steps or, code that can reproduce with charts demo

[dhhyuk]

Append Entry Code

func updateChartData() {
        var dataSets: [ScatterChartDataSet] = []

        let aliveEntry = aliveSensors.map {
            return Double($0.sensorVoltage) > self.VOLTAGE_MINIMUM ? ChartDataEntry(x: valueToGraphPosition(x: Double($0.sensorVoltage)), y: Double($0.sensorIlluminationAvg)) : ChartDataEntry(x: Double($0.sensorVoltage), y: Double($0.sensorIlluminationAvg))
        }

        let deadEntry = deadSensors.map {
            return Double($0.sensorVoltage) > self.VOLTAGE_MINIMUM ? ChartDataEntry(x: valueToGraphPosition(x: Double($0.sensorVoltage)), y: Double($0.sensorIlluminationAvg)) : ChartDataEntry(x: Double($0.sensorVoltage), y: Double($0.sensorIlluminationAvg))
        }
        print("Entry Count : \(aliveEntry.count), \(deadEntry.count)")

        let aliveSet = ScatterChartDataSet(values: aliveEntry, label: "Alive")
        aliveSet.setColor(UIColor.blue, alpha: 1.0)
        aliveSet.scatterShapeSize = 3
        aliveSet.setScatterShape(ScatterChartDataSet.Shape.circle)

        let deadSet = ScatterChartDataSet(values: deadEntry, label: "Dead")
        deadSet.setColor(UIColor.red, alpha: 1.0)
        deadSet.scatterShapeSize = 3
        deadSet.setScatterShape(ScatterChartDataSet.Shape.circle)

        dataSets.append(aliveSet)
        dataSets.append(deadSet)
        let data = ScatterChartData(dataSets: dataSets)
        scatterChartView.data = data
    }

And Chart Setting Code

        scatterChartView.delegate = self
        scatterChartView.xAxis.labelPosition = .bottom
        scatterChartView.xAxis.axisMinimum = -500
        scatterChartView.xAxis.axisMaximum = 19000
        scatterChartView.xAxis.gridLineWidth = 0

        let description = Description()
        description.text = ""
        scatterChartView.chartDescription = description

        let zero = ChartLimitLine(limit: 0, label: "0")
        zero.labelPosition = .leftBottom
        zero.lineColor = UIColor.gray
        zero.lineWidth = 0.5
        zero.valueFont = UIFont.systemFont(ofSize: 8)
        scatterChartView.xAxis.addLimitLine(zero)

        scatterChartView.xAxis.valueFormatter = IndexAxisValueFormatter(values: [])

The code to add data to the chart.

I have checked dataSet entry count when chartTranslated. but entry count not changed.
Same entry count and data count.

When scrolling, some entries disappeared, but entry count not changed.

I do not know why the data in the middle disappears.
Is there another way to check the drawDataSet?

(Thank you for helping me with my inexperienced English Talking. :))

[liuxuan30]

with your code I am not sure as well; what's the order when you setup chart data and configure charts? Which is first?

are you able to reproduce with ChartsDemo?

[dhhyuk]

do you mean i able to reproduce using ChartsDemo?
i followed chartsDomo code. i changed only datas.

[liuxuan30]

Yes, we need code so we can reproduce with ChartsDemo.

[JayGoTenna]

Hi guys,

I am seeing this exact same problem as dhhyuk. I attempted to repurpose a scatter chart as a sort of time line.....

I have forked the repo and altered the ScatterChart Data to reproduce this problem: https://github.com/JayGoTenna/Charts

OR

You could just change setDataCount in ScatterChartViewController.m to look like this:

- (void)setDataCount:(int)count range:(double)range
{
    NSMutableArray *yVals1 = [[NSMutableArray alloc] init];
//    NSMutableArray *yVals2 = [[NSMutableArray alloc] init];
//    NSMutableArray *yVals3 = [[NSMutableArray alloc] init];

    for (int i = 0; i < count; i++)
    {
        double val = (double) (arc4random_uniform(range)) + 3;
        [yVals1 addObject:[[ChartDataEntry alloc] initWithX:val y:1]];

//        val = (double) (arc4random_uniform(range)) + 3;
//        [yVals2 addObject:[[ChartDataEntry alloc] initWithX:(double)i + 0.33 y:val]];
//
//        val = (double) (arc4random_uniform(range)) + 3;
//        [yVals3 addObject:[[ChartDataEntry alloc] initWithX:(double)i + 0.66 y:val]];
    }

    ScatterChartDataSet *set1 = [[ScatterChartDataSet alloc] initWithValues:yVals1 label:@"DS 1"];
    [set1 setScatterShape:ScatterShapeSquare];
    [set1 setColor:ChartColorTemplates.colorful[0]];
//    ScatterChartDataSet *set2 = [[ScatterChartDataSet alloc] initWithValues:yVals2 label:@"DS 2"];
//    [set2 setScatterShape:ScatterShapeCircle];
//    set2.scatterShapeHoleColor = ChartColorTemplates.colorful[3];
//    set2.scatterShapeHoleRadius = 3.5f;
//    [set2 setColor:ChartColorTemplates.colorful[1]];
//    ScatterChartDataSet *set3 = [[ScatterChartDataSet alloc] initWithValues:yVals3 label:@"DS 3"];
//    [set3 setScatterShape:ScatterShapeCross];
//    [set3 setColor:ChartColorTemplates.colorful[2]];

    set1.scatterShapeSize = 8.0;
//    set2.scatterShapeSize = 8.0;
//    set3.scatterShapeSize = 8.0;

    NSMutableArray *dataSets = [[NSMutableArray alloc] init];
    [dataSets addObject:set1];
//    [dataSets addObject:set2];
//    [dataSets addObject:set3];

    ScatterChartData *data = [[ScatterChartData alloc] initWithDataSets:dataSets];
    [data setValueFont:[UIFont fontWithName:@"HelveticaNeue-Light" size:7.f]];

    _chartView.data = data;
}

now when you zoom in or out or scroll on the chart, you'll notice shapes disappear.....