The Select Data Source Dialog Box in Excel 2013
In Excel 2013, when you click the Select Data command button on the Design tab of the Chart Tools contextual tab (or press Alt+JCE), Excel opens a Select Data Source dialog box. The controls in this dialog box enable you to make the following changes to the source data:
Switch the row and column headings back and forth by clicking its Switch Row/Column button.
Edit the labels used to identify the data series in the legend or on the horizontal (category) by clicking the Edit button on the Legend Entries (Series) or Horizontal (Categories) Axis Labels side and then selecting the cell range with appropriate row or column headings in the worksheet.
Add additional data series to the chart by clicking the Add button on the Legend Entries (Series) side and then selecting the cell containing the heading for that series in the Series Name text box and the cells containing the values to be graphed in that series in the Series Values text box.
Delete a label from the legend by clicking its name in the Legend Entries (Series) list box and then clicking the Remove button.
Modify the order of the data series in the chart by clicking the series name in the Legend Entries (Series) list box and then clicking the Move Up button (the one with the arrow pointing upward) or the Move Down button (the one with the arrow pointing downward) until the data series appears in the desired position in the chart.
Indicate how to deal with empty cells in the data range being graphed by clicking the Hidden and Empty Cells button and then selecting the appropriate Show Empty Cells As option button (Gaps, the default; Zero and Span with Line, for line charts). Click the Show Data in Hidden Rows and Columns check box to have Excel graph data in the hidden rows and columns within the selected chart data range.