public void TestTrimNull()
{
var function = new TrimFunction();
Assert.That(function.Evaluate(new string[1]), Is.EqualTo(""));
}
public void TestNothingToTrim()
{
var function = new TrimFunction();
Assert.That(function.Evaluate("some text"), Is.EqualTo("some text"));
}
public void TestTrimEmpty()
{
var function = new TrimFunction();
Assert.That(function.Evaluate(""), Is.EqualTo(""));
}
public Vector <double> Trim(Vector <double> initialGuess, Vector <double> steps, TrimFunction trimFunction)
{
var x = initialGuess.Clone();
var dx = steps.Clone();
var y = trimFunction(x);
if (x.Count != dx.Count)
{
throw new TrimmerException("TrimInit and TrimSteps vectors must have same size");
}
if (x.Count != y.Count)
{
throw new TrimmerException("TrimInit and Trim vectors must have same size");
}
norm = y.Norm(2);
iterations = 0;
if (norm > MaxNorm)
{
throw new TrimmerException("Bad initial guess");
}
Matrix <double> J = Matrix <double> .Build.DenseIdentity(x.Count);
while (iterations < MaxIterations)
{
iterations++;
for (int c = 0; c < x.Count; c++)
{
// Central difference
var xp = x.Clone();
xp [c] = x [c] + dx [c] / 2.0;
var yp = trimFunction(xp);
var xm = x.Clone();
xm [c] = x [c] - dx [c] / 2.0;
var ym = trimFunction(xm);
for (int r = 0; r < y.Count; r++)
{
J[r, c] = (yp[r] - ym[r]) / dx[c];
}
}
//Console.WriteLine ("x: " + x);
//Console.WriteLine ("J: " + J);
//Console.WriteLine ("y: " + y);
// Solve x(n+1)=J^-1*(-y(n))+x(n)
var d = J.Solve(-y);
//Console.WriteLine ("d: " + d);
for (int i = 0; i < d.Count; i++)
{
if (double.IsNaN(d [i]))
{
throw new TrimmerException("No solution");
}
}
x += d;
// Evaluate result
y = trimFunction(x);
norm = y.Norm(2);
//Console.WriteLine (" #" + iterations + "\tnorm " + norm.ToStr() + "\tx " + x.ToStr() + "\ty " + y.ToStr());
if (norm < Tolerance)
{
return(x);
}
if (norm > MaxNorm)
{
throw new TrimmerException("Diverged");
}
}
if (iterations >= MaxIterations)
{
throw new TrimmerException("Exceeded max iterations");
}
return(x);
}
