|Mn/DOT Traffic Data|
You must select at least one detector to get DataPlot to make graphs. This is done by entering the detector index number at the bottom of the window, and pressing [Enter]. As many as ten individual detectors may be plotted at one time, although if more than one detector is selected then only one date may be plotted.
In addition to plotting individual detectors, Data Plot can also create composite detectors. A composite detector is a group of detectors which are averaged together and plotted as a single line on the graph. To create a composite detector, just enter two or more detector index numbers, with a space between each. This is useful for plotting mainline stations with multiple days.
An advanced feature of composite detectors is the ability to include ramp detectors in the composite. This is done by adding a plus "+" or minus "-" before a detector index. This has the effect of adding a ramp volume to the total before computing the average volume. Ramp detectors have no effect on the occupancy, density, or speed graphs. Note: all mainline detectors must be specified before any ramp detectors, because after a "+" or "-", all detectors are treated as ramp detectors.
At the top of the date selection calendar, there are four buttons for selecting the month and year to be displayed. The "<<" and ">>" buttons select the previous and next years. The "<" and ">" buttons select the previous and next months.
Once an axis has been selected, it is possible to "zoom in" on a smaller range of that axis. For a vertical axis, this is done by two buttons on the right side of the window, "+" and "-". The "+" button zooms in to a smaller range of values on the graph, and the "-" button zooms out to a larger range of values. Once zoomed in, the scroll bar next to those buttons may be used to select the actual range for the zoomed in view. There are also buttons and a scroll bar for controlling the horizontal axis just below the graph. They work in the same manner.
It is possible to see the points themselves, without lines connecting them. Simply right-click on the graph and de-select the "Connect points" check box that pops up.
To import data, choose "Import" from the "File" menu. Again, a client session of DataPlot will prompt you for local file system access and after granting that access, you will be presented with an "Open" dialog. Browse to the proper location and select the appropriate file. Click "Open" and that's it!
A note about importing and exporting... exporting will overwrite (not append) files. Importing requires the file to be in very specific layout. Although the file is simple ascii text format, it is recommended that you don't edit these files.
Data Plot is capable of displaying contour plots of the roadway. To access the plot, choose the tab at the top named "Contour Plot". Select the desired dates with the calendar and one section of a corridor with the drop down menus. Once you click 'OK', Data Plot will create the contour plots and display them in the window. This may take a couple minutes depending on the number of dates and the length of the roadway.
The plots will appear in several tabs for various measures, dates, and aggregations. To traverse these tabs either click the tab you want to see or scroll through them.
The x-axis is time of day, shown by vertical black lines at each 3-hour mark. The y-axis shows each station with enough (>95% complete) data in the selected section of the corridor. The plot is colored depending on the data set being examined.
Some plots, like some speed plots, do not always have enough detail to get a
good picture of the roadway. To help make things clearer, a slider is included
to adjust where the "center" of the data lies, as a fraction of the maximum
value. This will be colored yellow in most plots (capacity plots color
0 vehicles/hour white; this cannot be adjusted, despite the presence of a slider). The color scale is made of two linear functions: one from the
minimum to the "center", and one from the "center" to the maximum. After
changing the slider, select
File > Refresh or press
F5 to update the plot.
The menu bar at the top contains many useful tools for modifying the plots:
File > Refreshor press
F5to update the plot.
From within the contour plot, you can create a time lapse. A time lapse is an animation in which you can view the corridor throughout the day in a matter of seconds. The x-axis shows the stations on the selected section of the corridor, and the y-axis shows the relative values of the data set. The animation lasts as long as specified in the Time Lapse Length textbox. The time lapse uses whatever gradient is currently displayed on the contour plot.