Plot: Aggregation

The options described here are used to modify the existing line plot. Several options are available for changing the display style and adding new components, such as whiskers or Japanese candles, to the plot. These options are available on the Aggregation dialog as well as on the Aggregation tab of the Plot Layout dialog and the Plot: Aggregation tab of the Graph Options dialog.

Plot. Use the Plot drop-down box to select the plot to which you want to make changes. If you have several plots in one graph, assign names to each plot using the Name field on the Plot: General tab.

Aggregated Data. Use the Aggregated Data group to specify an aggregated line plot, where each plot point is computed as the mean of  k consecutive observations (where k is the Span).

Use Aggregation. Select the Use Aggregation check box to request aggregation of consecutive observations.

Span. If the Use aggregation check box is selected, then you can specify in the Span field the number k defining the Span of k consecutive observations from which the plot points (means) will be computed.

Properties. Use the Properties group to specify various additional properties of the (aggregated and/or stacked) line plot.

Stacked. Select the Stacked check box to create a stacked line plot. This check box is only available if more than one variable is represented (plotted) in the current line graph. In that case, the vertical plot positions (along the y-axis) for each consecutive case (plotted along the x-axis) is computed as the cumulative sum over the variables represented in the graph. So for example, if two variables are plotted, and for a particular X value (case) the Y value for the first variable is 2 and for the second variable it is 5, then the vertical (Y) plot positions for the line representing the first variable is 2, and for the second variable 2+5=7. In other words, the lines are stacked one on top the other. Note that only the Standard line Type is available for stacked line plots.

Type. Instead of summarizing the aggregation of values in a single plot point (mean), use the Type drop-down box to show the minimum and maximum values found in each span of consecutive (aggregated) values as Value Range Bars (high-low whiskers), or Japanese candles (boxes); if you select Standard then only the means for each span of consecutive values will be plotted. Note that this option is only available when the Stacked check box is cleared and the Use aggregation check box is selected.

Weight as Case Multipliers. Select the Weight as Case Multipliers check box in order for the (non-aggregated) line plot to use the Case weights as case multipliers, and duplicate points in the graph if they have Case weights w greater than or equal to 2 (the points will be duplicated w times); if this check box is cleared, then Case weights will be ignored in the plot, and each observation will only be used (plotted) once. Case weights will not be used if the Use aggregation check box is selected. Note that this check box is applicable when Case weights are specified for the current analysis or datafile, and when the Use aggregation check box is cleared. See Spreadsheet Case Weights or Analysis/Graph Case Weights for further details.