TimeDirection graph

A work college was wanting some trivial code to draw a time based direction plot, and insisted that I do it.

So here is my drawing class:

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace LineCurve
{
  public class TimeDirection
  {
    public void Draw(Graphics g, Panel pnl, List<KeyValuePair<int,float>> data, int maxtime)
    {
      using (Brush brush = new SolidBrush(Color.Blue))
      {
        float halfx = pnl.Width / 2.0f;
        float halfy = pnl.Height / 2.0f;
        float scale = Math.Min(halfx, halfy) / (float)maxtime;

        foreach (KeyValuePair<int, float> kvp in data)
        {
          int time = kvp.Key;
          double dir = kvp.Value / 180.0 * Math.PI;

          // subtrack y as 0 is top, and +y is bottom.
          float fx = (float)(halfx + (Math.Sin(dir) * scale * time));
          float fy = (float)(halfy - (Math.Cos(dir) * scale * time));

          g.FillRectangle(brush,fx, fy, 1.0f, 1.0f);
        }
      }
    }
  }
}

And given the input:

List<KeyValuePair<int,float>> data = new List<KeyValuePair<int,float>>();
for (int i = 0; i < 40; i++)
{
  data.Add(new KeyValuePair<int, float>(i, i * 9.0f));
}

Looks like this:

time/direction based graph

This code is released under the MIT license, except it may not be used for web-based weather applications.