public static void Gauss1d <T>(Narray <T> outa, Narray <T> ina, float sigma)
{
outa.Resize(ina.Dim(0));
// make a normalized mask
int range = 1 + (int)(3.0 * sigma);
Doublearray mask = new Doublearray(2 * range + 1);
for (int i = 0; i <= range; i++)
{
double y = Math.Exp(-i * i / 2.0 / sigma / sigma);
mask[range + i] = mask[range - i] = y;
}
double total = 0.0;
for (int i = 0; i < mask.Dim(0); i++)
{
total += mask[i];
}
for (int i = 0; i < mask.Dim(0); i++)
{
mask[i] /= total;
}
// apply it
int n = ina.Length();
for (int i = 0; i < n; i++)
{
total = 0.0;
for (int j = 0; j < mask.Dim(0); j++)
{
int index = i + j - range;
if (index < 0)
{
index = 0;
}
if (index >= n)
{
index = n - 1;
}
total += Convert.ToDouble(ina[index]) * mask[j]; // it's symmetric
}
outa[i] = (T)Convert.ChangeType(total, typeof(T));
}
}
