/// <summary>
/// Sorts the matrix slices into ascending order, according to the <i>natural ordering</i> of the matrix values in the given <i>[row,column]</i> position.
/// The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.
/// To sort ranges use sub-ranging viewsd To sort by other dimensions, use dice viewsd To sort descending, use flip views ...
/// <p>
/// The algorithm compares two 2-d slices at a time, determinining whether one is smaller, equal or larger than the other.
/// Comparison is based on the cell <i>[row,column]</i> within a slice.
/// Let <i>A</i> and <i>B</i> be two 2-d slicesd Then we have the following rules
/// <ul>
/// <li><i>A < B iff A.Get(row,column) < B.Get(row,column)</i>
/// <li><i>A == B iff A.Get(row,column) == B.Get(row,column)</i>
/// <li><i>A > B iff A.Get(row,column) > B.Get(row,column)</i>
/// </ul>
///
/// @param matrix the matrix to be sorted.
/// @param row the index of the row inducing the order.
/// @param column the index of the column inducing the order.
/// @return a new matrix view having slices sorted by the values of the slice view <i>matrix.viewRow(row).viewColumn(column)</i>.
/// <b>Note that the original matrix is left unaffected.</b>
/// @throws IndexOutOfRangeException if <i>row %lt; 0 || row >= matrix.Rows || column %lt; 0 || column >= matrix.Columns</i>.
/// </summary>
public ObjectMatrix3D sort(ObjectMatrix3D matrix, int row, int column)
{
if (row < 0 || row >= matrix.Rows)
{
throw new IndexOutOfRangeException("row=" + row + ", matrix=" + Formatter.Shape(matrix));
}
if (column < 0 || column >= matrix.Columns)
{
throw new IndexOutOfRangeException("column=" + column + ", matrix=" + Formatter.Shape(matrix));
}
int[] sliceIndexes = new int[matrix.Slices]; // indexes to reorder instead of matrix itself
for (int i = sliceIndexes.Length; --i >= 0;)
{
sliceIndexes[i] = i;
}
ObjectMatrix1D sliceView = matrix.ViewRow(row).ViewColumn(column);
IntComparator comp = new IntComparator((a, b) =>
{
IComparable av = (IComparable)(sliceView[a]);
IComparable bv = (IComparable)(sliceView[b]);
int r = av.CompareTo(bv);
return(r < 0 ? -1 : (r > 0 ? 1 : 0));
});
RunSort(sliceIndexes, 0, sliceIndexes.Length, comp);
// view the matrix according to the reordered slice indexes
// take all rows and columns in the original order
return(matrix.ViewSelection(sliceIndexes, null, null));
}
/// <summary>
/// Sorts the matrix slices according to the order induced by the specified comparator.
/// The returned view is backed by this matrix, so changes in the returned view are reflected in this matrix, and vice-versa.
/// The algorithm compares two slices (2-d matrices) at a time, determinining whether one is smaller, equal or larger than the other.
/// To sort ranges use sub-ranging viewsd To sort by other dimensions, use dice viewsd To sort descending, use flip views ...
/// <p>
/// <b>Example:</b>
/// <pre>
/// sort by sum of values in a slice
/// ObjectMatrix2DComparator comp = new ObjectMatrix2DComparator() {
/// public int compare(ObjectMatrix2D a, ObjectMatrix2D b) {
/// Object as = a.zSum(); Object bs = b.zSum();
/// return as %lt; bs ? -1 : as == bs ? 0 : 1;
/// }
/// };
/// sorted = quickSort(matrix,comp);
/// </pre>
///
/// @param matrix the matrix to be sorted.
/// @param c the comparator to determine the order.
/// @return a new matrix view having slices sorted as specified.
/// <b>Note that the original matrix is left unaffected.</b>
/// </summary>
public ObjectMatrix3D sort(ObjectMatrix3D matrix, ObjectMatrix2DComparator c)
{
int[] sliceIndexes = new int[matrix.Slices];
// indexes to reorder instead of matrix itself
for (int i = sliceIndexes.Length; --i >= 0;)
{
sliceIndexes[i] = i;
}
ObjectMatrix2D[] views = new ObjectMatrix2D[matrix.Slices]; // precompute views for speed
for (int i = views.Length; --i >= 0;)
{
views[i] = matrix.ViewSlice(i);
}
IntComparator comp = new IntComparator((a, b) => { return(c(views[a], views[b])); });
RunSort(sliceIndexes, 0, sliceIndexes.Length, comp);
// view the matrix according to the reordered slice indexes
// take all rows and columns in the original order
return(matrix.ViewSelection(sliceIndexes, null, null));
}
