append append_n_null append_null has init initSeq insert insert_n_null insert_n_null insert_null read read_all_names read_buffer_row_count read_column_count read_index read_info read_n read_n read_n_indices read_n_segments read_n_segments read_n_segments_to read_n_segments_to read_n_segments_to read_n_segments_to read_n_to read_n_to read_n_to read_n_to read_name read_row_count read_segment read_segment_to read_segment_to read_to read_to readAllNames readBufferRowCount readColumnCount readIndex readIndices readInfo readName readRowCount readSegment readSegmentSeq readSegmentSeq readSegmentSeqTo readSegmentTo readSeq readSeq readSeqTo readTo remove remove_n removeSeq rename update_name write write_n write_n write_n_segments write_n_segments write_segment writeSegment writeSegmentSeq writeSeq

read_to() [2/2] void read_to ( TColumn &  column ) const Read a column into an existing Column. Parameters column The Column object to which data should be written, name of which is used to specify the column to be read key The name or 0-based index of the column to be read There are several ways to read a column, which can be specified either by its name or 0-based index. The simplest way is to read the whole column as a new VecColumn with methods read(). In this case, the value type is given as the template parameter. In order to store the column data in an existing Column (e.g. PtrColumn), similar methods read_to() should be used. In this case, the value type is deduced and should not be specified. Example usages: // Create a new Column auto from_name = columns.read<float>("RA"); auto from_index = columns.read<float>(1); // Concatenate two columns into an existing Column long row_count = read_row_count(); std::vector<float> values(row_count * 2); PtrColumn<float> ra({"RA", "deg", 1}, row_count, &values[0]); PtrColumn<float> dec({"DEC", "deg", 1}, row_count, &values[row_count]); columns.read_to("RA", ra); columns.read_to("DEC", dec); Warning Methods read_to() do not allocate memory: the user must ensure that enough space has been allocated previously.