Customize starting index in LiveChart

Question

I am trying to draw a simple LineSeries with LiveChart. Because computer/array index by default starts with 0, and human (non-programmer) starts counting with 1, so I like to display the value's index starting with 1 (i.e. index+1), but could not figure out how to do this.

I read the LiveChart documentation on Types and Configurations, and tried to get a mapper of index + 1 into the SeriesCollection but I get an invalid argument error: cannot convert from 'LiveCharts.Configurations.CartesianMapper' to 'LiveCharts.Definitions.Series.ISeriesView'

var mapper1 = new CartesianMapper<double>()
        .X((value, index) => index + 1) 
        .Y((value, index) => value); 

sc = new SeriesCollection
{
    new LineSeries
    {
        Values = new ChartValues<double>()  {1,2,3,4,1,2,3,4,1,2},
    },
    mapper1
};

The documentation is quite unhelpful for specific problems, but since I've tinkered with LiveCharts a lot, I can provide some suggestions. Could you try `sc = new SeriesCollection(mapper1) { ... }` for setting the mapper, instead of your code. — Keyur PATEL, Aug 28 '17 at 04:57
@KeyurPATEL, jesus christ it works. If it tells me to pass the mappers to overload the constructor that would save me hours of trials... or may be I just overlook the document. Please answer it so I can select yours as the answer. — KMC, Aug 28 '17 at 05:11
There is also a property in `SeriesCollection` called `Configuration` that can be used to set a mapper. This can be set any time and the mapper will be used. — Tomas Kosar, Mar 08 '18 at 13:05

score 4 · Accepted Answer · answered Aug 28 '17 at 06:07

I can answer this only because I have had to tinker with LiveCharts myself, not because I got it from their documentation (although I did find it embedded here)

If you want to set a mapper specifically for one series, you can add it to the delcaration as follows:

var mapper1 = new CartesianMapper<double>()
        .X((value, index) => index + 1) 
        .Y((value, index) => value); 

sc = new SeriesCollection(mapper1)
{
    new LineSeries
    {
        Values = new ChartValues<double>()  {1,2,3,4,1,2,3,4,1,2},
    }
};

Alternatively, there is a way to set a global mapper for specific data types, e.g. if you're using MeasureModel:

var mapper = Mappers.Xy<MeasureModel>()
            .X(model => model.DateTime.Ticks)   //use DateTime.Ticks as X
            .Y(model => model.Value);           //use the value property as Y

//lets save the mapper globally.
Charting.For<MeasureModel>(mapper);

That example is from here.

Customize starting index in LiveChart

1 Answers1