/// <summary>
/// Replaces all cell values of the receiver with the values of another matrix.
/// Both matrices must have the same number of rows and columns.
/// If both matrices share the same cells (as is the case if they are views derived from the same matrix) and intersect in an ambiguous way, then replaces <i>as if</i> using an intermediate auxiliary deep copy of <i>other</i>.
/// </summary>
/// <param name="source">the source matrix to copy from (may be identical to the receiver).</param>
/// <returns><i>this</i> (for convenience only).</returns>
/// <exception cref="ArgumentException">if <i>columns() != source.columns() || rows() != source.rows()</i></exception>
public override ObjectMatrix2D Assign(ObjectMatrix2D source)
{
// overriden for performance only
if (!(source is DenseObjectMatrix2D))
{
return(base.Assign(source));
}
DenseObjectMatrix2D other = (DenseObjectMatrix2D)source;
if (other == this)
{
return(this); // nothing to do
}
CheckShape(other);
if (!this.IsView && !other.IsView)
{ // quickest
Array.Copy(other.Elements, 0, this.Elements, 0, this.Elements.Length);
return(this);
}
if (HaveSharedCells(other))
{
ObjectMatrix2D c = other.Copy();
if (!(c is DenseObjectMatrix2D))
{ // should not happen
return(base.Assign(other));
}
other = (DenseObjectMatrix2D)c;
}
Object[] elems = this.Elements;
Object[] otherElems = other.Elements;
if (Elements == null || otherElems == null)
{
throw new NullReferenceException();
}
int cs = this.ColumnStride;
int ocs = other.ColumnStride;
int rs = this.RowStride;
int ors = other.RowStride;
int otherIndex = other.Index(0, 0);
int index = base.Index(0, 0);
for (int row = Rows; --row >= 0;)
{
for (int i = index, j = otherIndex, column = Columns; --column >= 0;)
{
elems[i] = otherElems[j];
i += cs;
j += ocs;
}
index += rs;
otherIndex += ors;
}
return(this);
}
