values-are-stacked

Arguments: chart-view

Returns the value of the values-are-stacked property of a chart-view. The value may be set at creation time by passing the values-are-stacked initarg, or any time later by calling (setf values-are-stacked).

This property specifies whether the data values in a chart-view of a chart-widget are stacked to show cumulative values on the value-axis. The default value is nil.

This property is relevant only when the widget has multiple objects (see chart-objects), because otherwise there is nothing to stack.

For a bar-chart-view (when the chart-view of the chart-widget is :bar), a true value will stack the multiple bars of each chart item so that they lie end-to-end. A null value will place the bars side-by-side instead. The stacked option saves a lot of space, but can make it somewhat harder to compare the multiple chart objects. If bars are stacked and some values are above the base-value of the bar-chart-view while others are below, then all of the values that are above the base-value are stacked in one direction and all of the values that are below the base value are independently stacked in the other direction.

For a line-graph-view (when the chart-view of the chart-widget is :line), a true value will stack the data values so that the line for each chart object is relative to the lines of the chart objects below it. This is like a stacked area graph, though the areas between the lines are not filled. A null value will draw the lines independently of each other, which typically causes more crossing of the multiple lines.

For any true value other than :downward, the first object in the sequence of chart-objects is charted first, then the second object is stacked on the values of the first, and so on. For the special value :downward, the objects are stacked in the opposite order, which (when chart-orientation is :vertical) would match the direction in which the objects are listed from top to bottom in the chart's legend.

See chart-widget and also cg-chart-widget.htm.

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This page was not revised from the 10.0 page.
Created 2019.8.20.