/// <summary>
/// Gets or sets the matrix cell value at coordinate <i>[row,column]</i>.
///
/// <p>Provided with invalid parameters this method may return invalid objects without throwing any exception.
/// <b>You should only use this method when you are absolutely sure that the coordinate is within bounds.</b>
/// Precondition (unchecked): <i>0 <= column < columns() && 0 <= row < rows()</i>.
/// </summary>
/// <param name="row">the index of the row-coordinate.</param>
/// <param name="column">the index of the column-coordinate.</param>
/// <returns>the value at the specified coordinate.</returns>
public override double this[int row, int column]
{
get
{
int k = Indexes.BinarySearchFromTo(column, Starts[row], Starts[row + 1] - 1);
double v = 0;
if (k >= 0)
{
v = Values[k];
}
return(v);
}
set {
int k = Indexes.BinarySearchFromTo(column, Starts[row], Starts[row + 1] - 1);
if (k >= 0)
{ // found
if (value == 0)
{
Remove(row, k);
}
else
{
Values[k] = value;
}
return;
}
if (value != 0)
{
k = -k - 1;
Insert(row, column, k, value);
}
}
}