Time Plot Graphs

Time Plot graphs can be used for:

Determining trends or cyclical variations
Money distribution over time
Production over time
Price variation over time
Environmental changes over time

If your data consists of Time-value data pairs, then you will want to use a Time Plot graph. Time Plot graphs work almost exactly like X-Y graphs. Time Plot data items consist of two data values: the time and the value, which translate to an x and y coordinate, respectively. The data item is displayed as a symbol. You can also add a line, bubble, or fill area for the data item. Because of the nature of the coordinate system, Time Plot graphs do not have categories.

Time graphs work well when you are graphing the value of something at indiscrete intervals—in other words, you are sampling the data at random times. If you are sampling your data at regular intervals, or if you sample all of your data series at the exact same times, you will probably find it easier to use a graph in the Standard Data Class, using each category of data to represent a discrete point in time.

Example 13.12 below shows how a Time Plot graph works.

Time Plot graphs are in the Plot Data Class (see Chapter 12 for details). The time data value, by default, should be in the following format: %m/%d/%Y, where %m represents the month number, %d represents the day number, and %Y represents the four-digit year. You can change the date input format to anything you like. For instance, Example 13.12 uses a %H:%M format (meaning hour:minute, where all times occur on the same day). Refer to "Date Input Format (Time Plot)" in Chapter A of the PopChart Builder User Guide for information about changing this format.

To create a Time Plot graph with PopChart XML, create a Graph element and set its Type attribute to Time, as shown in the example below.