public static void ConvexHull()
{
int[] testSizes = new int[] { 12345, 100, 316, 1000, 3160, 10000, 31600, 100000, 316000, 1000000, 3160000, 10000000 };
for (int iter = 0; iter < testSizes.Length; iter++)
{
Random r = new Random();
List <PointD> points = new List <PointD>(testSizes[iter]);
for (int i = 0; i < points.Capacity; i++)
{
double size = r.NextDouble();
double ang = r.NextDouble() * (Math.PI * 2);
points.Add(new PointD(size * Math.Cos(ang), size * Math.Sin(ang)));
}
// Plus: test sorting time to learn how much of the time is spent sorting
var points2 = new List <PointD>(points);
EzStopwatch timer = new EzStopwatch(true);
points2.Sort((a, b) => a.X == b.X ? a.Y.CompareTo(b.Y) : (a.X < b.X ? -1 : 1));
Stopwatch timer2 = new Stopwatch(); timer2.Start();
int sortTime = timer.Restart();
IListSource <Point <double> > output = PointMath.ComputeConvexHull(points, true);
int hullTime = timer.Millisec;
Console.WriteLine("{0:c} (ticks:{1,10} freq:{2})", timer2.Elapsed, timer2.ElapsedTicks, Stopwatch.Frequency);
if (iter == 0)
{
continue; // first iteration primes the JIT/caches
}
Console.WriteLine("Convex hull of {0,8} points took {1} ms ({2} ms for sorting step). Output has {3} points.",
testSizes[iter], hullTime, sortTime, output.Count);
}
}
public void ComputeVertices()
{
////use convex hull to find vertices
planeVertices.Clear();
List <Point <double> > points2 = new List <Point <double> >();
foreach (MyVector3 p in planePoints)
{
Point <double> pt = new Point <double>(p.x, p.y);
points2.Add(pt);
}
List <Point <double> > convex_hull = PointMath.ComputeConvexHull(points2, false).ToList();
foreach (Point <double> point in convex_hull)
{
MyVector3 u = new MyVector3(point.X, point.Y, ComputeZ(point.X, point.Y));
planeVertices.Add(u);
}
ProjectVerticesTo2d();
//ComputePlaneArea();
}
// To recognize a scribble we require the simplified line to reverse
// direction at least three times. There are separate criteria for
// erasing a shape currently being drawn and for erasing existing
// shapes.
//
// The key difference between an "erase scribble" and a "cancel
// scribble" is that an erase scribble starts out as such, while
// a cancel scribble indicates that the user changed his mind, so
// the line will not appear to be a scribble at the beginning.
// The difference is detected by timestamps. For example, the
// following diagram represents an "erase" operation and a "cancel"
// operation. Assume the input points are evenly spaced in time,
// and that the dots represent points where the input reversed
// direction.
//
// Input points ..........................
// Reversals (erase) . . . . . .
// Reversals (cancel) . . . .
//
// So, a scribble is considered an erasure if it satisfies t0 < t1,
// where t0 is the time between mouse-down and the first reversal,
// and t1 is the time between the first and third reversals. A cancel
// operation satisfies t0 > t1 instead.
//
// Both kinds of scribble need to satisfy the formula LL*c > CHA,
// where c is a constant factor in pixels, LL is the drawn line
// length and CHA is the area of the Convex Hull that outlines the
// drawn figure. This formula basically detects that the user
// is convering the same ground repeatedly; if the pen reverses
// direction repeatedly but goes to new places each time, it's not
// considered an erasure scribble. For a cancel scribble, LL is
// computed starting from the first reversal.
IEnumerable <Shape> RecognizeScribbleForEraseOrCancel(DragState state, out bool cancel, out List <PointT> simplifiedSS)
{
cancel = false;
simplifiedSS = null;
var tolerance = state._inputTransform.Transform(new VectorT(0, 10)).Length();
var simplifiedMP = LineMath.SimplifyPolyline(
state.UnfilteredMousePoints.Select(p => p.Point), tolerance);
List <int> reversals = FindReversals(simplifiedMP, 3);
if (reversals.Count >= 3)
{
simplifiedSS = simplifiedMP.Select(p => state._inputTransform.Transform(p)).ToList();
// 3 reversals confirmed. Now decide: erase or cancel?
int[] timeStampsMs = FindTimeStamps(state.UnfilteredMousePoints, simplifiedMP);
int t0 = timeStampsMs[reversals[0]], t1 = timeStampsMs[reversals[2]] - t0;
cancel = t0 > t1 + 500;
// Now test the formula LL*c > CHA as explained above
IListSource <PointT> simplifiedMP_ = cancel ? simplifiedMP.Slice(reversals[0]) : simplifiedMP.AsListSource();
float LL = simplifiedMP_.AdjacentPairs().Sum(pair => pair.A.Sub(pair.B).Length());
var hull = PointMath.ComputeConvexHull(simplifiedMP);
float CHA = PolygonMath.PolygonArea(hull);
if (LL * EraseNubWidth > CHA)
{
// Erasure confirmed.
if (cancel)
{
return(EmptyList <Shape> .Value);
}
// Figure out which shapes to erase. To do this, we compute for
// each shape the amount of the scribble that overlaps that shape.
var simplifiedSS_ = simplifiedSS;
return(_doc.Shapes.Where(s => ShouldErase(s, simplifiedSS_)).ToList());
}
}
return(null);
}
public JsonResult ConvexHull(int Id, int Forecast)
{
if (Forecast > 0)
{
using (MeteoDataEntities me = new MeteoDataEntities())
{
var asciiResult = me.IndexMaps.Where(x => x.Id == Id).Select(x => x.IndexMapZipAscii).First();
Byte[] ascii = ex.Uncompress(asciiResult);
//System.IO.File.WriteAllBytes(@"C:\Static\test.asc", ascii);
#region Read ascii
List <AsciiValues> listasp = new List <AsciiValues>();
int counter = 0;
string line;
int ncols = 0;
int nrows = 0;
int xllcorner = 0;
int yllcorner = 0;
int cellsize = 0;
int NODATA_value = 0;
using (MemoryStream memoryStream = new MemoryStream(ascii))
{
using (StreamReader st = new StreamReader(memoryStream))
{
while ((line = st.ReadLine()) != null)
{
//System.Console.WriteLine(line);
if (!string.IsNullOrWhiteSpace(line))
{
counter++;
#region ASC Details
if (counter < 7)
{
string[] result = line.Split(' ');
if (result[0].Contains("ncols"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
ncols = number;
}
}
}
}
if (result[0].Contains("nrows"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
nrows = number;
}
}
}
}
if (result[0].Contains("xllcorner"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
xllcorner = number;
}
}
}
}
if (result[0].Contains("yllcorner"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
yllcorner = number;
}
}
}
}
if (result[0].Contains("cellsize"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
cellsize = number;
}
}
}
}
if (result[0].Contains("NODATA_value"))
{
for (int i = 1; i < result.Length; i++)
{
if (!String.IsNullOrWhiteSpace(result[i]))
{
int number;
if (int.TryParse(result[i], out number))
{
NODATA_value = number;
}
}
}
}
}
#endregion ASC Details
else
{
string[] result = line.Split(' ');
for (int i = 0; i < result.Length; i++)
{
int number;
if (int.TryParse(result[i], out number))
{
AsciiValues aspul = new AsciiValues()
{
X = xllcorner + (i * cellsize),
Y = (yllcorner + (nrows * cellsize)) - (cellsize * (counter - 7)),
Value = number
};
AsciiValues aspur = new AsciiValues()
{
X = xllcorner + (i * cellsize) + cellsize,
Y = (yllcorner + (nrows * cellsize)) - (cellsize * (counter - 7)),
Value = number
};
AsciiValues aspdl = new AsciiValues()
{
X = xllcorner + (i * cellsize),
Y = (yllcorner + (nrows * cellsize)) - (cellsize * (counter - 7)) - cellsize,
Value = number
};
AsciiValues aspdr = new AsciiValues()
{
X = xllcorner + (i * cellsize) + cellsize,
Y = (yllcorner + (nrows * cellsize)) - (cellsize * (counter - 7)) - cellsize,
Value = number
};
listasp.Add(aspul);
listasp.Add(aspur);
listasp.Add(aspdl);
listasp.Add(aspdr);
}
}
}
}
}
counter.ToString();
}
}
#endregion Read ascii
var points = listasp.Where(x => x.Value <= Forecast && x.Value > 0);
var finalpoints = points.Select(x => new Point <double>()
{
X = x.X, Y = x.Y
}).ToList();
var ConvexHullresult = PointMath.ComputeConvexHull(finalpoints, true);
return(this.Json(ConvexHullresult, JsonRequestBehavior.AllowGet));
}
}
else
{
return(this.Json(null, JsonRequestBehavior.AllowGet));
}
}
