Function densityplot_add 

pub fn densityplot_add<X: ToString, Y: ToString>(
    plot: &mut Plot<GridCanvas>,
    x: &[X],
    y: &[Y],
    options: LineplotSeriesOptions,
) -> Result<(), LineplotError>

Adds a density series to an existing density plot.

Errors

Returns LineplotError::LengthMismatch when lengths differ, LineplotError::EmptySeries for empty input, and LineplotError::InvalidNumericValue when parsing fails. Returns LineplotError::DensityPlotRequired when called on a non-density plot.