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Create Matrix.Slice.cs 

This class provides a new indexer for obtaining or setting submatrix / vector by using System.Range
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newxiumu 5 years ago
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  1. 175
      src/Numerics/LinearAlgebra/Matrix.Slice.cs

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src/Numerics/LinearAlgebra/Matrix.Slice.cs
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using System;
namespace MathNet.Numerics.LinearAlgebra
{
/// <summary>
/// This class is used for slice Matrix by using System.Range.
/// It is different from System.Range functions in the use of ".." syntax.
/// Because the when use ".." in array,like double[],the sliced array won't contain the end index.
/// However,in this Matrix<T>,it will contain the end index.
/// </summary>
/// <typeparam name="T"></typeparam>
public abstract partial class Matrix<T>
{
/// <summary>
/// Get or Set the SubMatrix by [Range,Range]
/// For example:
/// Matrix<double> mat = Matrix<double>.Build.Dense(10,10);
/// mat[1..2,2..3];
/// mat[1..2,^9..^1];
/// mat[..,2..3];
/// mat[1..2,2..3] = a new Matrix has the same dimension with this submatrix;
/// </summary>
/// <param name="rowRange">the Row Range,it must contain more than one Row</param>
/// <param name="columnRange">the Column Range,it must contain more than one Column</param>
/// <returns>A SubMatrix</returns>
public Matrix<T> this[Range rowRange, Range columnRange]
{
get
{
int rowStartIndex = rowRange.Start.IsFromEnd ? RowCount - rowRange.Start.Value - 1 : rowRange.Start.Value;
int rowEndIndex = rowRange.End.IsFromEnd ? RowCount - rowRange.End.Value - 1 : rowRange.End.Value;
int rowCount = rowEndIndex - rowStartIndex + 1;
if (rowCount <=1 || rowCount > RowCount)
{
throw new ArgumentException($"The argument Row Range:{rowRange} is wrong!");
}
int columnStartIndex = columnRange.Start.IsFromEnd ? ColumnCount - columnRange.Start.Value - 1 : columnRange.Start.Value;
int columnEndIndex = columnRange.End.IsFromEnd ? ColumnCount - columnRange.End.Value - 1 : columnRange.End.Value;
int columnCount = columnEndIndex - columnStartIndex + 1;
if (columnCount <= 1 || columnCount > ColumnCount)
{
throw new ArgumentException($"The argument Column Range:{columnRange} is wrong!");
}
var result = Build.SameAs(this, rowCount, columnCount);
Storage.CopySubMatrixTo(result.Storage, rowStartIndex, 0, rowCount, columnStartIndex, 0, columnCount, ExistingData.AssumeZeros);
return result;
}
set
{
int rowStartIndex = rowRange.Start.IsFromEnd ? RowCount - rowRange.Start.Value - 1 : rowRange.Start.Value;
int rowEndIndex = rowRange.End.IsFromEnd ? RowCount - rowRange.End.Value - 1 : rowRange.End.Value;
int rowCount = rowEndIndex - rowStartIndex + 1;
if (rowCount <= 1 || rowCount > RowCount)
{
throw new ArgumentException($"The argument Row Range:{rowRange} is wrong!");
}
int columnStartIndex = columnRange.Start.IsFromEnd ? ColumnCount - columnRange.Start.Value - 1 : columnRange.Start.Value;
int columnEndIndex = columnRange.End.IsFromEnd ? ColumnCount - columnRange.End.Value - 1 : columnRange.End.Value;
int columnCount = columnEndIndex - columnStartIndex + 1;
if (columnCount <= 1 || columnCount > ColumnCount)
{
throw new ArgumentException($"The argument Column Range:{columnRange} is wrong!");
}
value.Storage.CopySubMatrixTo(Storage, 0, rowStartIndex, rowCount, 0, columnStartIndex, columnCount);
}
}
/// <summary>
/// Get or Set the Column SubVector of the Matrix
/// </summary>
/// <param name="rowRange">the Row Range,it must contain more than one Row</param>
/// <param name="columnIndex">the column index</param>
/// <returns>a vector</returns>
public Vector<T> this[Range rowRange, int columnIndex]
{
get
{
int rowStartIndex = rowRange.Start.IsFromEnd ? RowCount - rowRange.Start.Value - 1 : rowRange.Start.Value;
int rowEndIndex = rowRange.End.IsFromEnd ? RowCount - rowRange.End.Value - 1 : rowRange.End.Value;
int rowCount = rowEndIndex - rowStartIndex + 1;
if (rowCount <= 1 || rowCount > RowCount)
{
throw new ArgumentException($"The argument Row Range:{rowRange} is wrong!");
}
if ((uint)columnIndex >= (uint)ColumnCount)
{
throw new ArgumentOutOfRangeException(nameof(columnIndex));
}
var ret = Vector<T>.Build.SameAs(this, rowCount);
Storage.CopySubColumnTo(ret.Storage, columnIndex, rowStartIndex, 0, rowCount);
return ret;
}
set
{
int rowStartIndex = rowRange.Start.IsFromEnd ? RowCount - rowRange.Start.Value - 1 : rowRange.Start.Value;
int rowEndIndex = rowRange.End.IsFromEnd ? RowCount - rowRange.End.Value - 1 : rowRange.End.Value;
int rowCount = rowEndIndex - rowStartIndex + 1;
if (rowCount <= 1 || rowCount > RowCount)
{
throw new ArgumentException($"The argument Row Range:{rowRange} is wrong!");
}
if ((uint)columnIndex >= (uint)ColumnCount)
{
throw new ArgumentOutOfRangeException(nameof(columnIndex));
}
value.Storage.CopyToSubColumn(Storage, columnIndex, 0, rowStartIndex, rowCount);
}
}
/// <summary>
/// Get or Set the row SubVector of the Matrix
/// </summary>
/// <param name="rowIndex">the column index</param>
/// <param name="columnRange">the Column Range,it must contain more than one Column</param>
/// <returns>a vector</returns>
public Vector<T> this[int rowIndex, Range columnRange]
{
get
{
int columnStartIndex = columnRange.Start.IsFromEnd ? ColumnCount - columnRange.Start.Value - 1 : columnRange.Start.Value;
int columnEndIndex = columnRange.End.IsFromEnd ? ColumnCount - columnRange.End.Value - 1 : columnRange.End.Value;
int columnCount = columnEndIndex - columnStartIndex + 1;
if (columnCount <= 1 || columnCount > ColumnCount)
{
throw new ArgumentException($"The argument Column Range:{columnRange} is wrong!");
}
if ((uint)rowIndex >= (uint)RowCount)
{
throw new ArgumentOutOfRangeException(nameof(rowIndex));
}
var ret = Vector<T>.Build.SameAs(this, columnCount);
Storage.CopySubRowTo(ret.Storage, rowIndex, columnStartIndex, 0, columnCount);
return ret;
}
set
{
int columnStartIndex = columnRange.Start.IsFromEnd ? ColumnCount - columnRange.Start.Value - 1 : columnRange.Start.Value;
int columnEndIndex = columnRange.End.IsFromEnd ? ColumnCount - columnRange.End.Value - 1 : columnRange.End.Value;
int columnCount = columnEndIndex - columnStartIndex + 1;
if (columnCount <= 1 || columnCount > ColumnCount)
{
throw new ArgumentException($"The argument Column Range:{columnRange} is wrong!");
}
if ((uint)rowIndex >= (uint)RowCount)
{
throw new ArgumentOutOfRangeException(nameof(rowIndex));
}
value.Storage.CopyToSubRow(Storage, rowIndex, 0, columnStartIndex, columnCount);
}
}
}
}
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