mpandroidchart the dot's color doesn't change in scatter chart - mpandroidchart

Question

I'm using MPandroidchart to draw scatter chart.
I want to make a scatter chart that has a base line.
If value over the base line, in my case 0.2, its color change to red.
If not, it color is blue.
This is the codes i did.
if (d>=0.5)
{
colors.add(getBaseContext().getResources().getColor(R.color.color_red));
} else
{
colors.add(getBaseContext().getResources().getColor(R.color.color_blue));
}
value1.add(new Entry(k,d));
But it didn't change dot's color, but change squre's color next to label
I have tried
1)
if(index == specificIndex) colors.add(Color);
else colors.add(NormalColor);
2)
ArrayList<Integer> color = new ArrayList<>();
if (YOUR_CONDITION) {
color.add(ColorTemplate.rgb("#f8bf94"));
yVals1.add(new Entry(VALUE, COUNTER));
} else {
color.add(ColorTemplate.rgb("#e0e0e0"));
yVals1.add(new Entry(VALUE, COUNTER));
}
set1.setColors(color);
3)
color.add(Color.RED);
color.add(context.getResources().getColor(R.color.your_defined_color_in_colors_xml));
dataSet.setCircleColors(color);
But it didn't work.
How can i solve this?

Answer 1

After spending hours with this same issue, I have realized that it is the result of a bug in the MPAndroidChart project.
Basically, in the ScatterChartRenderer, the colors array is being treated such that only even colors are being applied to data points. For each Entry i, the color is set to colors[i / 2] meaning that the same color will be applied to two different entries due to integer division. This results in only half of the colors array being used.
To resolve this issue quickly, my solution was to add each entry to the DataSet twice. This means two points are drawn on top of each other, but both have the proper color set.
I am submitting a pull request to hopefully fix this issue in the next release, but for now this quick hack should work.