/// <summary>
/// assume that the input matrix is purely binary, i.e. zeros and ones
/// </summary>
/// <param name="matrix">
/// </param>
/// <returns>
/// The <see cref="ArrayList"/>.
/// </returns>
public static ArrayList ShapesDetect(double[,] matrix)
{
var shapes = new ArrayList();
var random = new RandomNumber();
int mHeight = matrix.GetLength(0);
int mWidth = matrix.GetLength(1);
for (int x = 5; x < mWidth; x++)
{
for (int y = 0; y < mHeight - 1; y++)
{
if (matrix[y, x] != 1.0)
{
continue; // not in an object
}
if (matrix[y + 1, x] != 1.0)
{
y++;
continue; // shape must be > 2 pixels wide
}
// explore shape in y dimension
int rowWidth = 0;
while (rowWidth + y < mHeight && matrix[y + rowWidth, x] == 1.0)
{
rowWidth++;
}
rowWidth--; // back off one place
int yCentre = y + (rowWidth / 2); // position in centre of shape
if (InExistingShape(yCentre, x, shapes))
{
continue;
}
// explore shape in x dimension
int upDist = 0;
while (x + upDist < mWidth && matrix[yCentre, x + upDist] == 1.0)
{
upDist++;
}
if (matrix[yCentre, x + 1] == 0.0)
{
upDist = 1;
}
int dnDist = 0;
while (x - dnDist > 0 && matrix[yCentre, x - dnDist] == 1.0)
{
dnDist++;
}
dnDist--; // pull back one
// initialise possible shape.
int col1 = x - dnDist + 1;
int colWidth = upDist + dnDist - 2;
var shape = new Oblong(y, col1, y + rowWidth - 1, col1 + colWidth - 1);
shape.RandomNumber = random.GetInt(200); // set random number for id and color purposes
int[] centroid = shape.Centroid();
// LoggedConsole.WriteLine("Centroid=" + centroid[0] + ", " + centroid[1]);
// LoggedConsole.WriteLine("RowWidth=" + shape.RowWidth + " ColWidth=" + shape.ColWidth);
shapes.Add(shape);
// more to end of shape
y = shape.RowBottom;
}
x += 4; // jump through 5 lines at a time.
}
LoggedConsole.WriteLine("Number of shapes=" + shapes.Count);
shapes = ProcessShapes(shapes);
// Console.ReadLine();
return(shapes);
}
public RandomVariable(double mean, double SD, int seed)
{
this.mean = mean;
this.SD = SD;
this.R = new RandomNumber(seed);
}
/// <summary>
/// CONSTRUCTOR
/// </summary>
public RandomVariable()
{
this.R = new RandomNumber();
}
/// <summary>
/// CONSTRUCTOR
/// </summary>
/// <param name="mean"></param>
/// <param name="SD"></param>
public RandomVariable(double mean, double SD)
{
this.mean = mean;
this.SD = SD;
this.R = new RandomNumber();
}
/// <summary>
/// Runs a test of the ScanArrayForGratingPattern() method.
/// First constructs a grating signal, then embeds it in longer noise signal
/// The grating is defined by a period and the number of cycles.
/// The search is repeated many iterations in order to get everage accuracy.
/// Accuracy depends on relative levels of noise gain and signal gain i.e. the SNR.
/// </summary>
public static void Test_ScanArrayForGridPattern1()
{
int n = 500;
double[] v = new double[n];
var rn = new RandomNumber();
int maxIterations = 1000;
int count = 0;
double[] template = { 1.0, 0.0, 1.1, 0.1, 1.2, 0.2, 1.3, 0.3 };
//double[] template = { 1.5, 0.2, 0.8, 0.1, 0.9, 0.0, 0.8, 0.0 };
//double[] template = { 2.0, 0.0, 0.7, 0.0, 0.6, 0.0, 0.7, 0.0 };
//double[] template = { 4.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };
int numberOfCycles = 4;
int cyclePeriod = 64; //MUST BE AN EVEN NUMBER!!
int signalLength = numberOfCycles * cyclePeriod;
double[] signal = template;
if (cyclePeriod > 2)
{
int halfPeriod = cyclePeriod / 2;
signal = new double[signalLength];
for (int x = 0; x < template.Length; x++)
{
for (int p = 0; p < halfPeriod; p++)
{
signal[(x * halfPeriod) + p] = template[x]; //transfer signal
}
if (cyclePeriod > 6)
{
signal = DataTools.filterMovingAverage(signal, halfPeriod - 1);
}
signal = DataTools.normalise(signal);
} //for
} // if (cyclePeriod > 2)
DataTools.writeBarGraph(signal);
double bgNoiseGain = 0.1;
double signalGain = 0.13;
int locationOfSignalStart = 100;
int searchStep = 5;
int errorTolerance = cyclePeriod;
if (errorTolerance < searchStep)
{
errorTolerance = searchStep + 1;
}
//run many repeats of the detection to determine its accuracy. Noise in signal means result varies from iteration to iteration.
for (int iter = 0; iter < maxIterations; iter++)
{
//construct background signal.
for (int i = 0; i < n; i++)
{
v[i] = rn.GetDouble() * bgNoiseGain;
}
//add in the signal
for (int i = 0; i < signal.Length; i++)
{
v[locationOfSignalStart + i] += (signal[i] * signalGain);
}
//detect grating in signal
var output = ScanArrayForGratingPattern(v, searchStep, numberOfCycles, cyclePeriod);
int maxLocation = DataTools.GetMaxIndex(output);
if ((maxLocation > (locationOfSignalStart - errorTolerance)) && (maxLocation < (locationOfSignalStart + errorTolerance)))
{
Console.WriteLine("score = {0:f2}", output[maxLocation]);
count++;
}
}
Console.WriteLine("% correct = {0:f1}", 100 * count / (double)maxIterations);
}
