How to draw a line in line chart for single value in Charts(IOS)

Question

I need to draw a single value in line chart. Currently i am using ios-charts library for line graph purpose.

The data will be varied some times i'll get the single data inside the data set at that time i need to draw the single value in the line chart.

What i am getting:

What i required:

Please [edit] your question and share your code as a [example] showing what you have already tried. It’s very difficult to help you otherwise. See also [ask]. — koen, May 26 '22 at 15:47
It’s a contradiction to draw a line using only a single point so I am not surprised if the library doesn’t support it. — Joakim Danielson, May 26 '22 at 17:13

score 3 · Accepted Answer · edited May 27 '22 at 14:22

The library cannot do this automatically, but there is the following option.
You check if your data contains exactly one point. If yes, then you add a so called LimitLine.

For example:

let limitLine = ChartLimitLine(
   limit: value,
   label: labelText)

limitLine.lineColor = .blue
limitLine.labelPosition = .topLeft
limitLine.valueFont = UIFont.systemFont(ofSize: 14)

chartView.leftAxis.addLimitLine(limitLine)

score 3 · Answer 2 · answered Jul 11 '22 at 02:58

For Swift Charts (Xcode 14 Beta)

Should someone decide to do something similar with Apple's Swift Charts, RuleMark() can be used to draw the line and PointMark() for a point like this:

Chart() {
    RuleMark(
        xStart: .value("Start", 0),
        xEnd: .value("End", 20),
        y: .value("Value", 125)
    )
    
    PointMark(
        x: .value("X Value", 10),
        y: .value("Y Value", 125)
    )
}

Example Output:

How to draw a line in line chart for single value in Charts(IOS)

2 Answers2