/// <summary>
/// Checks whether the given matrix <i>A</i> is <i>rectangular</i>.
/// </summary>
/// <param name="a">
/// The matrix.
/// </param>
/// <exception cref="ArgumentOutOfRangeException">
/// If <i>A.Rows < A.Columns</i>.
/// </exception>
public void CheckRectangular(DoubleMatrix2D a)
{
if (a.Rows < a.Columns)
{
throw new ArgumentOutOfRangeException("Matrix must be rectangular: " + AbstractFormatter.Shape(a));
}
}
/// <summary>
/// Checks whether the given matrix <i>A</i> is <i>rectangular</i>.
/// </summary>
/// <param name="a">
/// The matrix.
/// </param>
/// <exception cref="ArgumentOutOfRangeException">
/// If <i>A.Rows < A.Columns</i>.
/// </exception>
public void CheckRectangular(DoubleMatrix2D a)
{
if (a.Rows < a.Columns)
{
throw new ArgumentOutOfRangeException(String.Format(Cern.LocalizedResources.Instance().Exception_MatrixMustBeRectangular, AbstractFormatter.Shape(a)));
}
}
/// <summary>
/// Sorts the matrix rows into ascending order, according to the <i>natural ordering</i> of the matrix values in the given column.
/// </summary>
/// <param name="matrix">
/// The matrix to be sorted.
/// </param>
/// <param name="column">
/// The index of the column inducing the order.
/// </param>
/// <returns>
/// A new matrix view having rows sorted by the given column.
/// </returns>
/// <exception cref="IndexOutOfRangeException">
/// If <i>column < 0 || column >= matrix.columns()</i>.
/// </exception>
public DoubleMatrix2D Sort(DoubleMatrix2D matrix, int column)
{
if (column < 0 || column >= matrix.Columns)
{
throw new IndexOutOfRangeException("column=" + column + ", matrix=" + AbstractFormatter.Shape(matrix));
}
var rowIndexes = new int[matrix.Rows]; // row indexes to reorder instead of matrix itself
for (int i = rowIndexes.Length; --i >= 0;)
{
rowIndexes[i] = i;
}
DoubleMatrix1D col = matrix.ViewColumn(column);
RunSort(
rowIndexes,
0,
rowIndexes.Length,
(a, b) =>
{
double av = col[a];
double bv = col[b];
if (Double.IsNaN(av) || Double.IsNaN(bv))
{
return(CompareNaN(av, bv)); // swap NaNs to the end
}
return(av < bv ? -1 : (av == bv ? 0 : 1));
});
// view the matrix according to the reordered row indexes
// take all columns in the original order
return(matrix.ViewSelection(rowIndexes, null));
}