/// <summary>
/// Defizzify a FuzzySet and get its CENTER OF GRAVITY
/// </summary>
/// <param name="fs">Input Set</param>
/// <returns>Center of Gravity</returns>
public static double DeFuzzifyCOG(FuzzySet fs)
{
if (fs == null) { return -1; }
int points = (int)(((double)fs.GetNumPoints()) * 1.9 + 1);
if (points < 21) points = 21;
if (points < 4 || points > 1000) { return -1; }
if (fs.Invalid()) { fs.Err = 10; return -1; }
double sumTop = 0;
double sumBottom = 0;
double w, s, r, step;
r = fs.HighRange - fs.LowRange;
step = r / (points - 1);
int i;
for (i = 0; i < points; i++)
{
w = fs.LowRange + step * i;
s = fs.Fuzzify(w);
sumTop = sumTop + s * w;
sumBottom = sumBottom + s;
}
if (AEqual(0, sumBottom)) { fs.Err = 15; return -1; }
return sumTop / sumBottom;
}
/// <summary>
/// Performs a UNION of two Fuzzy Sets
/// </summary>
/// <param name="fs1">Fuzzy Set 1</param>
/// <param name="fs2">Fuzzy Set 2</param>
/// <param name="colour">The colour to render the result</param>
/// <returns>Result Set</returns>
public static FuzzySet UnionFS(FuzzySet fs1, FuzzySet fs2, Brush colour)
{
FuzzySet result = new FuzzySet(); // just for error checking and returning
//verify...
if (fs1 == null || fs2 == null || fs1.Invalid() || fs2.Invalid())
{
result.SetErr(10);
return result;
}
if (!RangeEqual(fs1, fs2))
{
result.SetErr(11); return result;
}
result = new FuzzySet(fs1);
result.Clear();
//lets get to work
result.SetRange(fs1.GetLowRange(), fs1.GetHighRange());
double x = 0, y = 0;
double fs1x1, fs1x2, fs1y1, fs1y2;
double fs2x3, fs2x4, fs2y3, fs2y4;
double fs1s, fs1w, fs2s, fs2w;
int i, k, rc;
// traverse fs1 add all its points above fs2
for (i = 0; i < fs1.GetNumPoints(); i++)
{
fs1w = fs1.GetWorldValue(i);
fs1s = fs1.GetSetValue(i);
fs2s = fs2.Fuzzify(fs1w);
if (fs1s > fs2s || Operations.AEqual(fs1s, fs2s))
{
result.AddPoint(fs1w, fs1s, false, false);
}
}
// traverse fs2 add all its points above fs1
for (i = 0; i < fs2.GetNumPoints(); i++)
{
fs2w = fs2.GetWorldValue(i);
fs2s = fs2.GetSetValue(i);
fs1s = fs1.Fuzzify(fs2w);
if (fs2s > fs1s)
{
result.AddPoint(fs2w, fs2s, false, false);
}
}
// now traverse all line segments in fs1 testing for intersection with fs2
for (i = 1; i < fs1.GetNumPoints(); i++)
{
fs1x1 = fs1.GetWorldValue(i - 1);
fs1y1 = fs1.GetSetValue(i - 1);
fs1x2 = fs1.GetWorldValue(i);
fs1y2 = fs1.GetSetValue(i);
for (k = 1; k < fs2.GetNumPoints(); k++)
{
fs2x3 = fs2.GetWorldValue(k - 1);
fs2y3 = fs2.GetSetValue(k - 1);
fs2x4 = fs2.GetWorldValue(k);
fs2y4 = fs2.GetSetValue(k);
rc = Intersect(ref x, ref y,
fs1x1, fs1y1, fs1x2, fs1y2,
fs2x3, fs2y3, fs2x4, fs2y4);
if (rc == 0)
{
result.AddPoint(x, y, false, false);
}
}
}
result.ColapseSet();
result.LineColour = colour;
return result;
}
/**
* Defuzzify a set using the Sugeno style aproximation function
* if it fails it returns -1 (which may be a valid answer)
*/
/// <summary>
/// Defuzzify a set using the Sugeno style aproximation function
// if it fails it returns -1 (which may be a valid answer)
/// </summary>
/// <param name="fs"></param>
/// <returns></returns>
public static double DeFuzzifySFI(FuzzySet fs)
{
if (fs == null) { return -1; }
if (fs.Invalid()) { fs.Err = 10; return -1; }
double sumTop = 0;
double sumBottom = 0;
double w, s;
int i;
for (i = 0; i < fs.GetNumPoints(); i++)
{
w = fs.WorldValue[i];
s = fs.SetValue[i];
sumTop = sumTop + s * w;
sumBottom = sumBottom + s;
}
if (Operations.AEqual(0, sumBottom)) { fs.Err = 15; return -1; }
return sumTop / sumBottom;
}
/// <summary>
/// Performs a SCALE on a Fuzzy Set
/// </summary>
/// <param name="fs">The Fuzzy Set to Scale</param>
/// <param name="val">The scalar amount to Scale the Set</param>
/// <returns></returns>
public static FuzzySet ScaleFS(FuzzySet fs, double val)
{
FuzzySet retSet = new FuzzySet();
if (fs == null)
{
retSet.SetErr(10);
return retSet;
}
retSet = new FuzzySet(fs);
if (retSet.Invalid())
{
retSet.SetErr(10);
return retSet;
}
int i;
for (i = 0; i < retSet.GetNumPoints(); i++)
{
double w = retSet.GetWorldValue(i);
double s = retSet.GetSetValue(i) * val;
if (s > 1) s = 1;
if (s < 0) s = 0;
retSet.AdjustPoint(i, w, s);
}
return retSet;
}
/**
* Defuzzify a set using the Mean of Maximums aproximation function
* if it fails it returns -1 (which may be a valid answer)
*/
/// <summary>
/// Defizzify a FuzzySet and get its MEAN OF MAXIMUMS
/// </summary>
/// <param name="fs"></param>
/// <returns>Mean of Maximums</returns>
public static double DeFuzzifyMOM(FuzzySet fs)
{
if (fs == null) { return -1; }
if (fs.Invalid()) { fs.Err = 10; return -1; }
double m = fs.GetMaxSetValue();
double sumTop = 0;
double sumBottom = 0;
double w;
int i;
for (i = 0; i < fs.GetNumPoints(); i++)
{
if (AEqual(fs.SetValue[i], m))
{
w = fs.WorldValue[i];
sumTop = sumTop + w;
sumBottom = sumBottom + 1;
}
}
if (AEqual(0, sumBottom)) { fs.Err = 15; return -1; }
return sumTop / sumBottom;
}