private void AnalyzeEquirippleLpFilter()
{
var order = 47;
var fp = 0.15;
var fa = 0.18;
var ripplePass = 1.0; // dB
var rippleStop = 42.0; // dB
if (filterParamsDataGrid.RowCount > 0)
{
order = Convert.ToInt32(filterParamsDataGrid.Rows[0].Cells[1].Value);
fp = Convert.ToDouble(filterParamsDataGrid.Rows[1].Cells[1].Value);
fa = Convert.ToDouble(filterParamsDataGrid.Rows[2].Cells[1].Value);
ripplePass = Convert.ToDouble(filterParamsDataGrid.Rows[3].Cells[1].Value);
rippleStop = Convert.ToDouble(filterParamsDataGrid.Rows[4].Cells[1].Value);
}
orderNumeratorTextBox.Text = (order - 1).ToString();
orderDenominatorTextBox.Text = (order - 1).ToString();
var wp = Remez.DbToPassbandWeight(ripplePass);
var wa = Remez.DbToStopbandWeight(rippleStop);
_filter = new FirFilter(DesignFilter.FirEquirippleLp(order, fp, fa, wp, wa));
filterParamsDataGrid.RowCount = 5;
filterParamsDataGrid.Rows[0].Cells[0].Value = "order";
filterParamsDataGrid.Rows[0].Cells[1].Value = order;
filterParamsDataGrid.Rows[1].Cells[0].Value = "fp";
filterParamsDataGrid.Rows[1].Cells[1].Value = fp;
filterParamsDataGrid.Rows[2].Cells[0].Value = "fa";
filterParamsDataGrid.Rows[2].Cells[1].Value = fa;
filterParamsDataGrid.Rows[3].Cells[0].Value = "rp";
filterParamsDataGrid.Rows[3].Cells[1].Value = ripplePass;
filterParamsDataGrid.Rows[4].Cells[0].Value = "rs";
filterParamsDataGrid.Rows[4].Cells[1].Value = rippleStop;
}
private void AnalyzeEquirippleBsFilter()
{
var order = 51;
var fp1 = 0.19;
var fa1 = 0.21;
var fa2 = 0.39;
var fp2 = 0.41;
var ripplePass1 = 1.0;
var rippleStop = 24.0;
var ripplePass2 = 3.0;
if (filterParamsDataGrid.RowCount > 0)
{
order = Convert.ToInt32(filterParamsDataGrid.Rows[0].Cells[1].Value);
fp1 = Convert.ToDouble(filterParamsDataGrid.Rows[1].Cells[1].Value);
fa1 = Convert.ToDouble(filterParamsDataGrid.Rows[2].Cells[1].Value);
fa2 = Convert.ToDouble(filterParamsDataGrid.Rows[3].Cells[1].Value);
fp2 = Convert.ToDouble(filterParamsDataGrid.Rows[4].Cells[1].Value);
ripplePass1 = Convert.ToDouble(filterParamsDataGrid.Rows[5].Cells[1].Value);
rippleStop = Convert.ToDouble(filterParamsDataGrid.Rows[6].Cells[1].Value);
ripplePass2 = Convert.ToDouble(filterParamsDataGrid.Rows[7].Cells[1].Value);
}
orderNumeratorTextBox.Text = (order - 1).ToString();
orderDenominatorTextBox.Text = (order - 1).ToString();
var freqs = new[] { 0, fp1, fa1, fa2, fp2, 0.5 };
var weights = new[]
{
Remez.DbToPassbandWeight(ripplePass1),
Remez.DbToStopbandWeight(rippleStop),
Remez.DbToPassbandWeight(ripplePass2),
};
var remez = new Remez(order, freqs, new double[] { 1, 0, 1 }, weights);
_filter = new FirFilter(remez.Design());
var extrema = string.Join("\t", Enumerable.Range(0, remez.K).Select(e => remez.ExtremalFrequencies[e].ToString("F5")));
var message = $"Iterations: {remez.Iterations}\n\nEstimated order: {Remez.EstimateOrder(freqs, weights)}\n\nExtrema:\n{extrema}";
MessageBox.Show(message);
filterParamsDataGrid.RowCount = 8;
filterParamsDataGrid.Rows[0].Cells[0].Value = "order";
filterParamsDataGrid.Rows[0].Cells[1].Value = order;
filterParamsDataGrid.Rows[1].Cells[0].Value = "fp1";
filterParamsDataGrid.Rows[1].Cells[1].Value = fp1;
filterParamsDataGrid.Rows[2].Cells[0].Value = "fa1";
filterParamsDataGrid.Rows[2].Cells[1].Value = fa1;
filterParamsDataGrid.Rows[3].Cells[0].Value = "fa2";
filterParamsDataGrid.Rows[3].Cells[1].Value = fa2;
filterParamsDataGrid.Rows[4].Cells[0].Value = "fp2";
filterParamsDataGrid.Rows[4].Cells[1].Value = fp2;
filterParamsDataGrid.Rows[5].Cells[0].Value = "rp1";
filterParamsDataGrid.Rows[5].Cells[1].Value = ripplePass1;
filterParamsDataGrid.Rows[6].Cells[0].Value = "rs";
filterParamsDataGrid.Rows[6].Cells[1].Value = rippleStop;
filterParamsDataGrid.Rows[7].Cells[0].Value = "rp2";
filterParamsDataGrid.Rows[7].Cells[1].Value = ripplePass2;
}