DataViz Chart not Showing Up (2)

Hello, I’m trying to plot a chart using Dataviz, but, without success!

When I try to plot using integers, the graph appears, when I use Double values, the graph doesn’t appear.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void bunifuFlatButton1_Click(object sender, EventArgs e)
        {
            double [,] a = new double[21, 2] { { 59.2618639501813, 0 }, { 56.2987707526722, 0.722780356188258 }, { 53.3356775551632, 1.44556071237651 }, { 50.3725843576541, 2.16834106856477 }, { 47.409491160145, 2.89112142475303 }, { 44.446397962636, 3.61390178094129 }, { 41.4833047651269, 4.33668213712955 }, { 38.5202115676178, 5.0594624933178 }, { 35.5571183701088, 5.78224284950606 }, { 32.5940251725997, 6.50502320569432 }, { 29.6309319750907, 7.22780356188258 }, { 26.6678387775816, 7.95058391807083 }, { 23.7047455800725, 8.28912148599399 }, { 20.7416523825635, 8.28912148599399 }, { 17.7785591850544, 8.28912148599399 }, { 14.8154659875453, 8.28912148599399 }, { 11.8523727900363, 8.28912148599399 }, { 8.8892795925272, 8.28912148599399 }, { 5.92618639501813, 8.28912148599399 }, { 2.96309319750907, 8.28912148599399 }, { 0, 8.28912148599399 } };
            bunifuDataViz1.Title = "Test";

            Bunifu.DataViz.WinForms.Canvas canvas = new Bunifu.DataViz.WinForms.Canvas();
            Bunifu.DataViz.WinForms.DataPoint datapoint = new Bunifu.DataViz.WinForms.DataPoint(Bunifu.DataViz.WinForms.BunifuDataViz._type.Bunifu_splineArea);

            for (int i = 0; i < 21; i++)
            {
                datapoint.addxy(a[i, 0], a[i, 1]);
                //datapoint.addxy(i, i);
            }
            

            // Add data sets to canvas
            canvas.addData(datapoint);

            //render canvas
            bunifuDataViz1.Render(canvas);
        }
    }
}

Can anyone support me?
Thanks a lot.