C# Vector.Clear方法代码示例

        /// <summary>
        /// Copies the requested row elements into a new <see cref="Vector{T}"/>.
        /// </summary>
        /// <param name="rowIndex">The row to copy elements from.</param>
        /// <param name="columnIndex">The column to start copying from.</param>
        /// <param name="length">The number of elements to copy.</param>
        /// <param name="result">The <see cref="Vector{T}"/> to copy the column into.</param>
        /// <exception cref="ArgumentNullException">If the result <see cref="Vector{T}"/> is <see langword="null" />.</exception>
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="rowIndex"/> is negative,
        /// or greater than or equal to the number of columns.</exception>        
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="columnIndex"/> is negative,
        /// or greater than or equal to the number of rows.</exception>        
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="columnIndex"/> + <paramref name="length"/>  
        /// is greater than or equal to the number of rows.</exception>
        /// <exception cref="ArgumentException">If <paramref name="length"/> is not positive.</exception>
        /// <exception cref="ArgumentOutOfRangeException">If <strong>result.Count &lt; length</strong>.</exception>
        public override void Row(int rowIndex, int columnIndex, int length, Vector<Complex> result)
        {
            if (result == null)
            {
                throw new ArgumentNullException("result");
            }

            if (rowIndex >= RowCount || rowIndex < 0)
            {
                throw new ArgumentOutOfRangeException("rowIndex");
            }

            if (columnIndex >= ColumnCount || columnIndex < 0)
            {
                throw new ArgumentOutOfRangeException("columnIndex");
            }

            if (columnIndex + length > ColumnCount)
            {
                throw new ArgumentOutOfRangeException("length");
            }

            if (length < 1)
            {
                throw new ArgumentException(Resources.ArgumentMustBePositive, "length");
            }

            if (result.Count < length)
            {
                throw new ArgumentException(Resources.ArgumentVectorsSameLength, "result");
            }

            // Determine bounds in columnIndices array where this item should be searched (using rowIndex)
            var startIndex = _rowIndex[rowIndex];
            var endIndex = rowIndex < _rowIndex.Length - 1 ? _rowIndex[rowIndex + 1] : NonZerosCount;

            if (startIndex == endIndex)
            {
                result.Clear();
            }
            else
            {
                // If there are non-zero elements use base class implementation
                for (int i = columnIndex, j = 0; i < columnIndex + length; i++, j++)
                {
                    // Copy code from At(row, column) to avoid unnecessary lock
                    var index = FindItem(rowIndex, i);
                    result[j] = index >= 0 ? _nonZeroValues[index] : 0.0;
                }
            }
        }

        /// <summary>
        /// Subtracts another vector to this vector and stores the result into the result vector.
        /// </summary>
        /// <param name="other">
        /// The vector to subtract from this one.
        /// </param>
        /// <param name="result">
        /// The vector to store the result of the subtraction.
        /// </param>
        protected override void DoSubtract(Vector<Complex> other, Vector<Complex> result)
        {
            if (ReferenceEquals(this, other))
            {
                result.Clear();
                return;
            }

            for (var index = 0; index < Count; index++)
            {
                result.At(index, At(index) - other.At(index));
            }
        }

        /// <summary>
        /// Multiplies a scalar to each element of the vector and stores the result in the result vector.
        /// </summary>
        /// <param name="scalar">
        /// The scalar to multiply.
        /// </param>
        /// <param name="result">
        /// The vector to store the result of the multiplication.
        /// </param>
        protected override void DoMultiply(Complex scalar, Vector<Complex> result)
        {
            if (scalar == Complex.One)
            {
                if (!ReferenceEquals(this, result))
                {
                    CopyTo(result);
                }

                return;
            }

            if (scalar == Complex.Zero)
            {
                result.Clear();
                return;
            }

            var sparseResult = result as SparseVector;
            if (sparseResult == null)
            {
                result.Clear();
                for (var index = 0; index < NonZerosCount; index++)
                {
                    result.At(_nonZeroIndices[index], scalar * _nonZeroValues[index]);
                }
            }
            else
            {
                if (!ReferenceEquals(this, result))
                {
                    sparseResult.NonZerosCount = NonZerosCount;
                    sparseResult._nonZeroIndices = new int[NonZerosCount];
                    Buffer.BlockCopy(_nonZeroIndices, 0, sparseResult._nonZeroIndices, 0, _nonZeroIndices.Length * Constants.SizeOfInt);
                    sparseResult._nonZeroValues = new Complex[_nonZeroValues.Length];
                }
                
                Control.LinearAlgebraProvider.ScaleArray(scalar, _nonZeroValues, sparseResult._nonZeroValues);
            }
        }

        /// <summary>
        /// Subtracts another vector to this vector and stores the result into the result vector.
        /// </summary>
        /// <param name="other">
        /// The vector to subtract from this one.
        /// </param>
        /// <param name="result">
        /// The vector to store the result of the subtraction.
        /// </param>
        protected override void DoSubtract(Vector<Complex> other, Vector<Complex> result)
        {
            if (ReferenceEquals(this, other))
            {
                result.Clear();
                return;
            }

            var otherSparse = other as SparseVector;
            if (otherSparse == null)
            {
                base.DoSubtract(other, result);
                return;
            }

            var resultSparse = result as SparseVector;
            if (resultSparse == null)
            {
                base.DoSubtract(other, result);
                return;
            }

            // TODO (ruegg, 2011-10-11): Options to optimize?

            var otherStorage = otherSparse._storage;
            if (ReferenceEquals(this, resultSparse))
            {
                int i = 0, j = 0;
                while (j < otherStorage.ValueCount)
                {
                    if (i >= _storage.ValueCount || _storage.Indices[i] > otherStorage.Indices[j])
                    {
                        var otherValue = otherStorage.Values[j];
                        if (!Complex.Zero.Equals(otherValue))
                        {
                            _storage.InsertAtIndexUnchecked(i++, otherStorage.Indices[j], -otherValue);
                        }
                        j++;
                    }
                    else if (_storage.Indices[i] == otherStorage.Indices[j])
                    {
                        // TODO: result can be zero, remove?
                        _storage.Values[i++] -= otherStorage.Values[j++];
                    }
                    else
                    {
                        i++;
                    }
                }
            }
            else
            {
                result.Clear();
                int i = 0, j = 0, last = -1;
                while (i < _storage.ValueCount || j < otherStorage.ValueCount)
                {
                    if (j >= otherStorage.ValueCount || i < _storage.ValueCount && _storage.Indices[i] <= otherStorage.Indices[j])
                    {
                        var next = _storage.Indices[i];
                        if (next != last)
                        {
                            last = next;
                            result.At(next, _storage.Values[i] - otherSparse.At(next));
                        }
                        i++;
                    }
                    else
                    {
                        var next = otherStorage.Indices[j];
                        if (next != last)
                        {
                            last = next;
                            result.At(next, At(next) - otherStorage.Values[j]);
                        }
                        j++;
                    }
                }
            }
        }

        /// <summary>
        /// Copies the values of this vector into the target vector.
        /// </summary>
        /// <param name="target">
        /// The vector to copy elements into.
        /// </param>
        /// <exception cref="ArgumentNullException">
        /// If <paramref name="target"/> is <see langword="null"/>.
        /// </exception>
        /// <exception cref="ArgumentException">
        /// If <paramref name="target"/> is not the same size as this vector.
        /// </exception>
        public override void CopyTo(Vector<Complex> target)
        {
            if (target == null)
            {
                throw new ArgumentNullException("target");
            }

            if (Count != target.Count)
            {
                throw new ArgumentException(Resources.ArgumentVectorsSameLength, "target");
            }

            if (ReferenceEquals(this, target))
            {
                return;
            }

            var otherVector = target as SparseVector;
            if (otherVector == null)
            {
                target.Clear();

                for (var index = 0; index < NonZerosCount; index++)
                {
                    target.At(_nonZeroIndices[index], _nonZeroValues[index]);
                }
            }
            else
            {
                // Lets copy only needed data. Portion of needed data is determined by NonZerosCount value
                otherVector._nonZeroValues = new Complex[NonZerosCount];
                otherVector._nonZeroIndices = new int[NonZerosCount];
                otherVector.NonZerosCount = NonZerosCount;

                if (NonZerosCount != 0)
                {
                    CommonParallel.For(0, NonZerosCount, index => otherVector._nonZeroValues[index] = _nonZeroValues[index]);
                    Buffer.BlockCopy(_nonZeroIndices, 0, otherVector._nonZeroIndices, 0, NonZerosCount * Constants.SizeOfInt);
                }
            }
        }

        /// <summary>
        /// Negates vector and saves result to <paramref name="result"/>
        /// </summary>
        /// <param name="result">Target vector</param>
        protected override void DoNegate(Vector<Complex> result)
        {
            var sparseResult = result as SparseVector;
            if (sparseResult == null)
            {
                result.Clear();
                for (var index = 0; index < _storage.ValueCount; index++)
                {
                    result.At(_storage.Indices[index], -_storage.Values[index]);
                }
            }
            else
            {
                if (!ReferenceEquals(this, result))
                {
                    sparseResult._storage.ValueCount = _storage.ValueCount;
                    sparseResult._storage.Indices = new int[_storage.ValueCount];
                    Buffer.BlockCopy(_storage.Indices, 0, sparseResult._storage.Indices, 0, _storage.ValueCount * Constants.SizeOfInt);
                    sparseResult._storage.Values = new Complex[_storage.ValueCount];
                    Array.Copy(_storage.Values, sparseResult._storage.Values, _storage.ValueCount);
                }

                Control.LinearAlgebraProvider.ScaleArray(-Complex.One, sparseResult._storage.Values, sparseResult._storage.Values);
            }
        }

        /// <summary>
        /// Multiplies this matrix with a vector and places the results into the result matrix.
        /// </summary>
        /// <param name="rightSide">The vector to multiply with.</param>
        /// <param name="result">The result of the multiplication.</param>
        /// <exception cref="ArgumentNullException">If <paramref name="rightSide"/> is <see langword="null" />.</exception>
        /// <exception cref="ArgumentNullException">If <paramref name="result"/> is <see langword="null" />.</exception>
        /// <exception cref="ArgumentException">If <strong>result.Count != this.RowCount</strong>.</exception>
        /// <exception cref="ArgumentException">If <strong>this.ColumnCount != <paramref name="rightSide"/>.Count</strong>.</exception>
        public override void Multiply(Vector<Complex> rightSide, Vector<Complex> result)
        {
            if (rightSide == null)
            {
                throw new ArgumentNullException("rightSide");
            }

            if (ColumnCount != rightSide.Count)
            {
                throw new ArgumentException(Resources.ArgumentMatrixDimensions, "rightSide");
            }

            if (result == null)
            {
                throw new ArgumentNullException("result");
            }

            if (RowCount != result.Count)
            {
                throw new ArgumentException(Resources.ArgumentMatrixDimensions, "result");
            }

            if (ReferenceEquals(rightSide, result))
            {
                var tmp = result.CreateVector(result.Count);
                Multiply(rightSide, tmp);
                tmp.CopyTo(result);
            }
            else
            {
                // Clear the result vector
                result.Clear();

                // Multiply the elements in the vector with the corresponding diagonal element in this.
                for (var r = 0; r < Data.Length; r++)
                {
                    result[r] = Data[r] * rightSide[r];
                }
            }
        }

        /// <summary>
        /// Copies the requested column elements into the given vector.
        /// </summary>
        /// <param name="columnIndex">The column to copy elements from.</param>
        /// <param name="rowIndex">The row to start copying from.</param>
        /// <param name="length">The number of elements to copy.</param>
        /// <param name="result">The <see cref="Vector{T}"/> to copy the column into.</param>
        /// <exception cref="ArgumentNullException">If the result <see cref="Vector{T}"/> is <see langword="null" />.</exception>
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="columnIndex"/> is negative,
        /// or greater than or equal to the number of columns.</exception>        
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="rowIndex"/> is negative,
        /// or greater than or equal to the number of rows.</exception>        
        /// <exception cref="ArgumentOutOfRangeException">If <paramref name="rowIndex"/> + <paramref name="length"/>  
        /// is greater than or equal to the number of rows.</exception>
        /// <exception cref="ArgumentException">If <paramref name="length"/> is not positive.</exception>
        /// <exception cref="ArgumentOutOfRangeException">If <strong>result.Count &lt; length</strong>.</exception>
        public override void Column(int columnIndex, int rowIndex, int length, Vector<Complex> result)
        {
            if (result == null)
            {
                throw new ArgumentNullException("result");
            }

            if (columnIndex >= ColumnCount || columnIndex < 0)
            {
                throw new ArgumentOutOfRangeException("columnIndex");
            }

            if (rowIndex >= RowCount || rowIndex < 0)
            {
                throw new ArgumentOutOfRangeException("rowIndex");
            }

            if (rowIndex + length > RowCount)
            {
                throw new ArgumentOutOfRangeException("length");
            }

            if (length < 1)
            {
                throw new ArgumentException(Resources.ArgumentMustBePositive, "length");
            }

            if (result.Count < length)
            {
                throw new ArgumentException(Resources.ArgumentVectorsSameLength, "result");
            }

            // Clear the result and copy the diagonal entry.
            result.Clear();
            if (columnIndex >= rowIndex && columnIndex < rowIndex + length && columnIndex < Data.Length)
            {
                result[columnIndex - rowIndex] = Data[columnIndex];
            }
        }

        /// <summary>
        /// Left multiply a matrix with a vector ( = vector * matrix ) and place the result in the result vector.
        /// </summary>
        /// <param name="leftSide">The vector to multiply with.</param>
        /// <param name="result">The result of the multiplication.</param>
        /// <exception cref="ArgumentNullException">If <paramref name="leftSide"/> is <see langword="null" />.</exception>
        /// <exception cref="ArgumentNullException">If the result matrix is <see langword="null" />.</exception>
        /// <exception cref="ArgumentException">If <strong>result.Count != this.ColumnCount</strong>.</exception>
        /// <exception cref="ArgumentException">If <strong>this.RowCount != <paramref name="leftSide"/>.Count</strong>.</exception>
        public override void LeftMultiply(Vector<Complex> leftSide, Vector<Complex> result)
        {
            if (leftSide == null)
            {
                throw new ArgumentNullException("leftSide");
            }

            if (RowCount != leftSide.Count)
            {
                throw DimensionsDontMatch<ArgumentException>(this, leftSide, "leftSide");
            }

            if (result == null)
            {
                throw new ArgumentNullException("result");
            }

            if (ColumnCount != result.Count)
            {
                throw DimensionsDontMatch<ArgumentException>(this, result, "result");
            }

            if (ReferenceEquals(leftSide, result))
            {
                var tmp = result.CreateVector(result.Count);
                LeftMultiply(leftSide, tmp);
                tmp.CopyTo(result);
            }
            else
            {
                // Clear the result vector
                result.Clear();

                // Multiply the elements in the vector with the corresponding diagonal element in this.
                for (var r = 0; r < _data.Length; r++)
                {
                    result[r] = _data[r] * leftSide[r];
                }
            }
        }

        /// <summary>
        /// Subtracts another vector to this vector and stores the result into the result vector.
        /// </summary>
        /// <param name="other">
        /// The vector to subtract from this one.
        /// </param>
        /// <param name="result">
        /// The vector to store the result of the subtraction.
        /// </param>
        protected override void DoSubtract(Vector<Complex> other, Vector<Complex> result)
        {
            if (ReferenceEquals(this, other))
            {
                result.Clear();
                return;
            }

            var otherSparse = other as SparseVector;
            if (otherSparse == null)
            {
                base.DoSubtract(other, result);
                return;
            }

            var resultSparse = result as SparseVector;
            if (resultSparse == null)
            {
                base.DoSubtract(other, result);
                return;
            }

            // TODO (ruegg, 2011-10-11): Options to optimize?

            if (ReferenceEquals(this, resultSparse))
            {
                int i = 0, j = 0;
                while (i < NonZerosCount || j < otherSparse.NonZerosCount)
                {
                    if (i < NonZerosCount && j < otherSparse.NonZerosCount && _nonZeroIndices[i] == otherSparse._nonZeroIndices[j])
                    {
                        _nonZeroValues[i++] -= otherSparse._nonZeroValues[j++];
                    }
                    else if (j >= otherSparse.NonZerosCount || i < NonZerosCount && _nonZeroIndices[i] < otherSparse._nonZeroIndices[j])
                    {
                        i++;
                    }
                    else
                    {
                        var otherValue = otherSparse._nonZeroValues[j];
                        if (otherValue != Complex.Zero)
                        {
                            InsertAtUnchecked(i++, otherSparse._nonZeroIndices[j], -otherValue);
                        }
                        j++;
                    }
                }
            }
            else
            {
                result.Clear();
                int i = 0, j = 0, last = -1;
                while (i < NonZerosCount || j < otherSparse.NonZerosCount)
                {
                    if (j >= otherSparse.NonZerosCount || i < NonZerosCount && _nonZeroIndices[i] <= otherSparse._nonZeroIndices[j])
                    {
                        var next = _nonZeroIndices[i];
                        if (next != last)
                        {
                            last = next;
                            result.At(next, _nonZeroValues[i] - otherSparse.At(next));
                        }
                        i++;
                    }
                    else
                    {
                        var next = otherSparse._nonZeroIndices[j];
                        if (next != last)
                        {
                            last = next;
                            result.At(next, At(next) - otherSparse._nonZeroValues[j]);
                        }
                        j++;
                    }
                }
            }
        }