To switch from a dot plot to a histogram, change the Y-Axis parameter to "Histogram". To switch from a histogram to a dot plot, switch the Y-Axis parameter back to anything else.
In histogram mode, you may overlay histograms of other files from the same project. Click the icon in the lower left corner and select other files to overlay.
When overlays are displayed, a legend will appear in the upper right corner.
There are multiple scales that can be selected for the y-axis when displaying a histogram. When you are viewing a single histogram the histogram curve will not look different when selecting different scales. However, when viewing histogram overlays, the scaling can make a big difference. Scaling options include:
The y-axis is scaled to the the number of events in each histogram bin.
The histogram bins are normalized to the mode (the peak of the histogram) and displayed as a percentage of the peak value.
You can switch between different histogram scaling types by clicking on the y-axis scale of the histogram itself. That will bring up a menu, where you can select the scaling type you would like to apply.