void txtInput_TextChanged(object sender, TextChangedEventArgs e)
{
int validRows = 0;
foreach (Row row in rows)
{
row.OddsRatio.Text = string.Empty;
}
foreach (Row row in rows)
{
double scoreTest;
double casesTest;
double controlsTest;
if (string.IsNullOrEmpty(row.Score.Text) || string.IsNullOrEmpty(row.Cases.Text) || string.IsNullOrEmpty(row.Controls.Text) || !double.TryParse(row.Score.Text, out scoreTest) || !double.TryParse(row.Cases.Text, out casesTest) || !double.TryParse(row.Controls.Text, out controlsTest))
{
break;
}
validRows++;
}
if (validRows > 0)
{
double[] scores = new double[validRows];
double[] cases = new double[validRows];
double[] controls = new double[validRows];
for (int x = 0; x < validRows; x++)
{
scores[x] = double.Parse(rows[x].Score.Text);
cases[x] = double.Parse(rows[x].Cases.Text);
controls[x] = double.Parse(rows[x].Controls.Text);
}
ChiSquareResult result = GetChiSquareForTrend(scores, cases, controls);
for (int x = 0; x < result.GetOddsRatios().Length; x++)
{
rows[x].OddsRatio.Text = result.GetOddsRatios()[x].ToString("N3");
}
txtChiSquare.Text = result.GetChi() == 0 ? "0" : result.GetChi().ToString("N5");
txtPValue.Text = result.GetPValue() == 0 ? "0" : result.GetPValue().ToString("N5");
}
else
{
txtChiSquare.Text = "...";
txtPValue.Text = "...";
}
}
public ChiSquareResult GetChiSquareForTrend(double[] col1, double[] col2, double[] col3)
{
ChiSquareResult result = new ChiSquareResult();
double[] acrude = new double[col1.Length];
double[] bcrude = new double[col1.Length];
double[] mhORad = new double[col1.Length];
double[] mhORbc = new double[col1.Length];
double[] oddsRatios = new double[col1.Length];
int levels = col1.Length;
double ccrude = 0;
double dcrude = 0;
double ttot;
double Vsum = 0;
double V1sum = 0;
double XMHchisq = 0;
double T1 = 0;
double T2 = 0;
double T3 = 0;
double n1 = 0;
double n2 = 0;
double n = 0;
double OR = 1.0;
double x, a, b, m;
double abase = col2[0];
double bbase = col3[0];
ccrude += abase;
dcrude += bbase;
for (int t = 0; t < levels; t++)
{
x = col1[t];
a = col2[t];
b = col3[t];
acrude[t] += a;
bcrude[t] += b;
m = a + b;
T1 += a * x;
T2 += m * x;
T3 += m * x * x;
n1 += a;
n2 += b;
n += a + b;
OR = (a * bbase) / (b * abase);
if (t > 0)
{
ttot = a + bbase + b + abase;
mhORad[t] += a * bbase / ttot;
mhORbc[t] += b * abase / ttot;
}
oddsRatios[t] = OR;
}
result.SetOddsRatios(oddsRatios);
Vsum += (n1 * n2 * (n * T3 - (T2 * T2))) / (n * n * (n - 1));
V1sum += T1 - ((n1 / n) * T2);
XMHchisq += ((V1sum - 0.5) * (V1sum - 0.5)) / Vsum;
result.SetChi(XMHchisq);
result.SetPValue(calcP(XMHchisq, 1));
return(result);
}