/// <summary>
/// Removes dimensions of length 1 from the array.
/// </summary>
/// <param name="array">The array.</param>
public static Array Squeeze(this Array array)
{
var dimensions = array.GetLength().Where(x => x != 1).ToArray();
if (dimensions.Length == 0)
{
dimensions = new[] { 1 }
}
;
Array res;
if (array.IsJagged())
{
#if NETSTANDARD1_4
throw new NotSupportedException("Squeeze with jagged arrays is not supported in .NET Standard 1.4.");
#else
res = Jagged.Zeros(array.GetInnerMostType(), dimensions);
Copy(array, res);
#endif
}
else
{
res = Matrix.Zeros(array.GetInnerMostType(), dimensions);
Buffer.BlockCopy(array, 0, res, 0, res.GetNumberOfBytes());
}
return(res);
}
/// <summary>
/// Gets the transpose of a matrix.
/// </summary>
/// <param name="matrix">A matrix.</param>
/// <returns>The transpose of the given matrix.</returns>
public static TItem[][] Transpose <TCollection, TItem>(this TCollection matrix)
where TCollection : ICollection, IEnumerable <TItem[]>
{
var rows = matrix.Count;
if (rows == 0)
{
return(new TItem[rows][]);
}
var cols = matrix.Columns();
#if CHECKS
if (!IsRectangular(matrix))
{
throw new ArgumentException("Only rectangular matrices can be transposed.");
}
#endif
var result = Jagged.Zeros <TItem>(cols, rows);
var i = 0;
foreach (var row in matrix)
{
for (var j = 0; j < result.Length; j++)
{
result[j][i] = row[j];
}
i++;
}
return(result);
}
/// <summary>
/// Converts a matrix represented as a nested list of lists into a jagged matrix.
/// </summary>
public static T[][] ToJagged <T>(this IList <IList <T> > values)
{
var rows = values.Rows();
var cols = values.Columns();
var result = Jagged.Zeros <T>(rows, cols);
for (var i = 0; i < values.Count; i++)
{
for (var j = 0; j < values[i].Count; j++)
{
result[i][j] = values[i][j];
}
}
return(result);
}