Introduction to 1-D Visualization
One dimensional (1-D) data has a magnitude and one location. Typically that location refers to a spatial location, though that is not strictly necessary. For example, it can be a temporal location or a person as well. One-dimensional is used in Digital Signal Processing. Take the following example:
Jan 1973 9175 Feb 1973 9395 Mar 1973 9271 Apr 1973 9291 May 1973 9262 Jun 1973 9213 Jul 1973 9217 Aug 1973 9168 Sep 1973 9065 Oct 1973 9223 Nov 1973 9160 Dec 1973 9063
Here we see that location is a date in time. The magnitude given is just a number. Without further information, it would be difficult to derive any useful information from it. The magnitude could be the number of widgets that a salesperson sold in a month. In this case, the magnitude is thousands of barrels of oil produced in the United States per day. This 1-D series is best viewed as a line graph.
With the line graph, three items are of obvious interest. The first is that the trend for oil production in the U.S. has been falling over the past three decades.
The second item of interest is that this is true except for one decade: from 1977 to 1986. The obvious question is "Why did U.S. production increase from 1977 to 1986?" The answer is that 1977 was the year that the Trans-Alaska Pipeline opened.
A third item of interest is that the production of oil in the U.S. fell precipitously in September of 2005. For those on the Mississippi-Louisiana Gulf Coast, the answer is immediately obvious. Hurricanes Katrina and Rita devastated the production and refinement of oil in the region.
This shows the power of visualization to gain insight into a topic.