Next, we can make the height of each “data rectangle” a full height of "1", and its y origin to be "0" (the bottom). We can also add a legend to display the column names in front of each "bar line" in the bar codes, to obtain a "distributed histograms" visualization.

This view displays the distribution of 4 criteria along longitude. Notice the less densely populated areas of the middle west and how eastern cities tend to have a higher education index (second line).

This view starts to remind of the parallel histograms, and we would like to move seamlessly to a parallel histogrm view.