public NewtonsViewModel Calculate(NewtonsModel model)
{
decimal DDFX0, DFX0, DP = 0, DP0 = 0, x0 = 0, x1 = 0, fx1 = 0, DFX1 = 0, DDFX1 = 0, RelError = 0;
int cond = 0;
string derivative1 = GetDerivativeString(model.Func);
string derivative2 = GetDerivativeString(derivative1);
decimal fx = FunctionCalculate(model.PointX, model.Func);
x0 = model.PointX;
DFX0 = FunctionCalculate(model.PointX, derivative1);
DDFX0 = FunctionCalculate(model.PointX, derivative2);
int k = 0;
do
{
if (cond == 2)
{
break;
}
k++;
ProgressBarIncrement?.Invoke(1);
DDFX0 = FunctionCalculate(x0, derivative2);
if (Math.Abs(DDFX0) <= model.Epsilon)
{
cond = 1;
}
else
{
DP = DFX0 / DDFX0;
}
if (k == 1)
{
DP0 = DP;
}
if (Math.Sign(DP0) == Math.Sign(DP))
{
x1 = x0 - DP;
}
else
{
x1 = x0 - DP / model.R;
}
DP0 = DP;
fx1 = FunctionCalculate(x1, model.Func);
DFX1 = FunctionCalculate(x1, derivative1);
RelError = 2 * Math.Abs(DP) / Math.Abs(x1) + model.Epsilon;
if (RelError < model.Delta && cond != 1)
{
cond = 2;
}
x0 = x1;
DFX0 = DFX1;
} while (k <= model.IterationMax);
if (k < model.IterationMax)
{
ProgressBarIncrement?.Invoke(model.IterationMax - k + 1);
}
return(new NewtonsViewModel
{
RelError = RelError,
Fx = fx,
Iteration = k,
X = x1,
Dfx1 = DFX1,
Cond = cond,
});
}
private async void button1_Click(object sender, EventArgs e)
{
try
{
labelerr.Text = "";
_fx = comboBoxf.Text;
if (v() != 0)
{
var model = new NewtonsModel
{
Func = _fx,
Tol = double.Parse(tolBox.Text),
IterationMax = int.Parse(k_maxBox.Text),
PointX = decimal.Parse(aBox.Text),
Delta = (decimal)double.Parse(DeltaBox.Text),
Epsilon = (decimal)double.Parse(tolBox.Text),
R = decimal.Parse(RBox.Text)
};
progressBar1.Visible = true;
progressBar1.Maximum = model.IterationMax + 1;
progressBar1.Value = 0;
var stopWatch = new Stopwatch();
stopWatch.Start();
var newtonsMethod = new NewtonsMethod();
newtonsMethod.ProgressBarIncrement += ProgressBarIncrement;
var result = await Task.Run(() => newtonsMethod.Calculate(model));
stopWatch.Stop();
var ts = stopWatch.Elapsed;
if (!string.IsNullOrWhiteSpace(result.Error))
{
MessageBox.Show(result.Error);
}
else
{
Sec.Text = ts.TotalSeconds.ToString("0.0");
fx1outBox.Text = result.Fx.ToString(" 0e0");
x1uotFBox.Text = result.X.ToString(CultureInfo.InvariantCulture);
outTolBox.Text = result.RelError.ToString("0e0");
countinerBox.Text = result.Iteration.ToString();
// fx1outBox.Text = result.Fx.ToString(CultureInfo.InvariantCulture);
outdfx1.Text = result.Dfx1.ToString(CultureInfo.InvariantCulture);
if (result.Iteration == model.IterationMax && result.RelError > (decimal)model.Tol)
{
labelerr.Text = @"Решение с заданной точностью \n за K_Max(" + model.IterationMax +
@")итераций не удалось найти.";
}
}
newtonsMethod.ProgressBarIncrement -= ProgressBarIncrement;
}
}
catch (Exception ex)
{
MessageBox.Show(@"Не удалось распознать F. " + ex.Message);
}
}
