public static void RowPermute <T>(Narray <T> data, Narray <int> permutation)
{
CHECK_ARG(data.Dim(0) == permutation.Length(), "data.Dim(0) == permutation.Length()");
Narray <bool> finished = new Narray <bool>(data.Dim(0));
finished.Fill(false);
for (int start = 0; start < finished.Length(); start++)
{
if (finished[start])
{
continue;
}
int index = start;
Narray <T> value = new Narray <T>();
RowCopy(value, data, index);
for ( ; ;)
{
int next = permutation[index];
if (next == start)
{
break;
}
RowCopy(data, index, next);
index = next;
CHECK_ARG(!finished[index], "!finished[index]");
finished[index] = true;
index = next;
}
RowCopy(data, index, value);
finished[index] = true;
}
}
/// <summary>
/// Permute the elements of an array given a permutation.
/// </summary>
public static void Permute <T>(Narray <T> data, Narray <int> permutation)
{
if (!data.SameDims(permutation))
{
throw new Exception("CHECK_ARG: data.SameDims(permutation)");
}
Narray <bool> finished = new Narray <bool>(data.Length());
finished.Fill(false);
for (int start = 0; start < finished.Length(); start++)
{
if (finished[start])
{
continue;
}
int index = start;
T value = data[index];
for ( ; ;)
{
int next = permutation[index];
if (next == start)
{
break;
}
data[index] = data[next];
index = next;
//CHECK_ARG(!finished[index] && "not a permutation");
if (finished[index])
{
throw new Exception("CHECK_ARG: !finished[index]");
}
finished[index] = true;
index = next;
}
data[index] = value;
finished[index] = true;
}
}
public static void Fill <S>(Narray <T> a, S value)
{
a.Fill(value);
}
