/// <summary>
/// Returns a hash code for this instance.
/// </summary>
/// <returns>
/// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.
/// </returns>
public override int GetHashCode()
{
var hashNum = Math.Min(NonZerosCount, 20);
long hash = 0;
for (var i = 0; i < hashNum; i++)
{
#if SILVERLIGHT
hash ^= Precision.DoubleToInt64Bits(this._nonZeroValues[i].GetHashCode());
#else
hash ^= BitConverter.DoubleToInt64Bits(_nonZeroValues[i].GetHashCode());
#endif
}
return(BitConverter.ToInt32(BitConverter.GetBytes(hash), 4));
}