Example #1
0
        /// <summary>
        /// 切片
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public IDataFrame this[SliceLabel s]
        {
            get
            {
                List <object> objs   = new List <object>();
                List <TIndex> indexs = null;
                if (_rawIndex != null)
                {
                    indexs = new List <TIndex>();
                }
                NDArray nDArray = null;
                //转换获取的标签行索引
                int start = 0;
                int end   = int.MaxValue;

                if (!string.IsNullOrEmpty(s.StartLabel))
                {
                    start = Index.GetPosition(s.StartLabel);
                }
                if (!string.IsNullOrEmpty(s.EndLabel))
                {
                    end = Index.GetPosition(s.EndLabel);
                }
                //验证长度
                var lengthVail = Values.size / Values.shape[1] - 1;
                var length     = end;
                if (end > lengthVail)
                {
                    length = lengthVail;
                }

                //验证开始和结束位置
                VailStartAndEnd(start, length, lengthVail);
                bool desc = s.Step < 0;
                //修正start和length,降序
                if (desc)
                {
                    int temp = start;
                    start  = length - 1;
                    length = temp;
                }
                for (int i = start; Calc(i, length, desc, true); i += s.Step)
                {
                    //获取下标
                    int index = GetIndex(i, lengthVail);
                    if (_rawIndex != null)
                    {
                        indexs.Add(_rawIndex[index]);
                    }
                    var value = Values[index] as NDArray;
                    objs.AddRange(value.Data <object>());
                }
                nDArray = np.array(objs.ToArray(), Values.dtype);
                int ndim = Columns.Size;
                nDArray.reshape(objs.Count / ndim, ndim);
                var result = new DataFrame <TIndex>(nDArray, indexs, _rawColumns, _dtype);
                return(result);
            }
        }
Example #2
0
        public void Create_implicit()
        {
            SliceLabel sliceLabel = "row1:row2:3";

            Assert.Equal("row1", sliceLabel.StartLabel);
            Assert.Equal("row2", sliceLabel.EndLabel);
            Assert.Equal(3, sliceLabel.Step);
        }