/**
* Constructs a new {@code GroupBy}
*
* @param l the {@link List} containing the items used as input to the
* key generating function.
* @param fn the {@link Function} to be used to generate the keys which describe
* the like contents of each grouping.
*/
public GroupBy(List <T> l, Func <T, R> fn)
{
this.iter = l;
this.fn = fn;
this.range = IntGenerator.Of(0, iter.Count);
if (range.MoveNext())
{
T t = iter[range.Current];
//next = new Pair<T, R>(t, fn.apply(t));
//T t = (T) Convert.ChangeType(range.Current, typeof(T));
next = new Tuple <T, R>(t, fn(t));
}
}
/**
* Like {@link #neighborhood(int, int)}, except that the neighborhood isn't truncated when it's
* near an edge. It wraps around to the other side.
*
* @param centerIndex The index of the point. The coordinates are expressed as a single index by
* using the dimensions as a mixed radix definition. For example, in dimensions
* 42x10, the point [1, 4] is index 1*420 + 4*10 = 460.
* @param radius The radius of this neighborhood about the centerIndex.
* @return The points in the neighborhood, including centerIndex.
*/
public int[] WrappingNeighborhood(int centerIndex, int radius)
{
int[] cp = CoordinatesFromIndex(centerIndex);
IntGenerator[] igs = ArrayUtils.Range(0, dimensions.Length)
.Select(i => new IntGenerator(cp[i] - radius, Math.Min((cp[i] - radius) + dimensions[i] - 1, cp[i] + radius) + 1))
.ToArray();//IntGenerator[]::new
List <List <int> > result = new List <List <int> >();
result.Add(new List <int>());
List <List <int> > interim = new List <List <int> >();
for (int i = 0; i < igs.Length; i++)
{
IntGenerator pool = igs[i];
int size = result.Count;
interim.Clear();
interim.AddRange(result);
result.Clear();
for (int x = 0; x < size; x++)
{
List <int> lx = interim[x];
pool.Reset();
for (int y = 0; y < pool.Count; y++)
{
pool.MoveNext();
int py = ArrayUtils.Modulo(pool.Current, dimensions[i]);
List <int> tl = new List <int>();
tl.AddRange(lx);
tl.Add(py);
result.Add(tl);
}
}
}
return(result.AsParallel().Select(tl => IndexFromCoordinates(tl.ToArray())).ToArray());
}
/**
* Get the points in the neighborhood of a point.
*
* A point's neighborhood is the n-dimensional hypercube with sides ranging
* [center - radius, center + radius], inclusive. For example, if there are two
* dimensions and the radius is 3, the neighborhood is 6x6. Neighborhoods are
* truncated when they are near an edge.
*
* @param centerIndex The index of the point. The coordinates are expressed as a single index by
* using the dimensions as a mixed radix definition. For example, in dimensions
* 42x10, the point [1, 4] is index 1*420 + 4*10 = 460.
* @param radius The radius of this neighborhood about the centerIndex.
* @return The points in the neighborhood, including centerIndex.
*/
public int[] Neighborhood(int centerIndex, int radius)
{
centerPosition = CoordinatesFromIndex(centerIndex);
igs = ArrayUtils.Range(0, dimensions.Length)
.Select(i => IntGenerator.Of(Math.Max(0, centerPosition[i] - radius), Math.Min(dimensions[i] - 1, centerPosition[i] + radius) + 1))
.ToArray();//IntGenerator[].@new
List <List <int> > result = new List <List <int> >();
result.Add(new List <int>());
List <List <int> > interim = new List <List <int> >();
foreach (IntGenerator pool in igs)
{
int size = result.Count;
interim.Clear();
interim.AddRange(result);
result.Clear();
for (int x = 0; x < size; x++)
{
List <int> lx = interim[x];
pool.Reset();
for (int y = 0; y < pool.Count; y++)
{
pool.MoveNext();
int py = pool.Current;
List <int> tl = new List <int>();
tl.AddRange(lx);
tl.Add(py);
result.Add(tl);
}
}
}
return(result.Select(tl => IndexFromCoordinates(tl.ToArray())).ToArray());
}
