Graph Overlays
Often it is useful to plot two or more data sets or population on the same axes. This makes it easy to compare the data, using differing colors to show multiple populations at the same time.
Overlays may be created on either univariate (right) or bivariate displays (below). Within the Layout Editor you can edit the color and order of the items, to customize the look of the overlay graph that best highlights your data. Once an overlay has been defined, the layout editor can create the same graph for many different samples or sets of samples, by iterating over a group in the workspace.
To create an overlay, drag a graph into the Layout Editor. Then drag a second on top of the first one. As the mouse moves into the original graph item, you'll see that it highlights its borders to signify that it will accept the contents of the drag. Drop the second graph (or more, if you had multiple nodes selected in the workspace) on top of the original, and an overlay is automatically created.
The Overlay Legend
As soon as you release the second node on the first, the graph will change into an overlay. Overlays are recognizable by the existence of a legend on the right side of the graph. The number of the rows in the legend shows the number of layers in the overlay. The graphs often change from black and white to color, as each data set gets its own color within the overlay.
The legend provides the user interface to edit several aspects of the overlay. Click the mouse once on the legend to select it. Then click on any of the elements to change them.
Clicking and drag the mouse on the black square handles of the legend to resize it. Click on the title area to move the legend.
Click and drag on the names in the legend to move them up or down. The order of the lines in the legend mirrors the order of the graphs displayed. Moving a graph's name to the top of the list moves the graph to the top of the overlay stack. Because events in front can obscure others, you may want to have the smaller populations on top of the larger ones, though this depends greatly on the context of your analysis. Dragging the order of the layers will cause the graph to be redrawn, so you can quickly see which layers you want to feature in the top positions. Right-click on a layer name to select Remove Layer.
Clicking the mouse in the colored box at the left side of the legend will pop up a rainbow palette, to let you change the colors of the layers in the graph.
The content and appearance of the legend itself can be edited by double-clicking on the text of the legend. This produces the Legend Properties dialog shown at the right. Here you can select color and style for text, box and background. You can also choose to display more information using the Insert drop-down list.
Select the parameter to which your statistic should be applied from the Parameter dropdown list. Note the additional options:
- Add for all parameters
- Add for all fluorescence parameters
Using these options will save you the tedious job of selecting and adding each channel individually. Unwanted channels can be deleted from the Legend by right-clicking and selecting Remove layer.
The legend is used to control all of the attributes of the graphs appearance. By default the legend is visible if there are multiple items in an overlay, and hidden for single histograms or 2D plots. If you want to edit the color, line weight, or dashing of a single graph, you can double click on the graph, and check the Show Legend box on the Annotate tab.
Histograms can optionally be offset when they are overlaid, so as to distinguish the curves better. The feature, as well as how much of an offset is used are specified in the Annotate tab of the Layout Item Definition dialog, summoned by double clicking the graph (or right-clicking it and choosing Properties, or selecting Properties from the Object menu).
You can also select the graph and drag on the corner handles to adjust the graph's appearance.
