private IntermediatePointResult IntermediatePoint(
MultidimensionalFunctionFDF fdf,
Vector <double> x,
Vector <double> p,
double lambda,
double pg,
double stepa,
double stepc,
double fa,
double fc,
Vector <double> x1,
Vector <double> dx,
double step,
double f)
{
double stepb = 0, fb;
Trial:
{
double u = Math.Abs(pg * lambda * stepc);
stepb = 0.5 * stepc * u / ((fc - fa) + u);
}
TakeStep(x, p, stepb, lambda, x1, dx);
if (x.Equals(x1))
{
return(new IntermediatePointResult
{
Step = 0,
F = fa,
Gradient = fdf.DF(x1)
});
}
fb = fdf.F(x1);
if (fb >= fa && stepb > 0)
{
fc = fb;
stepc = stepb;
goto Trial;
}
var gradient = fdf.DF(x1);
return(null);
}
