TIGER Shapefile Options

Database with rules for Tiger files. It will be in the main program directory.  You can open it and edit it like any database.
  • Toggle display with Y/N in the PLOT field.
  • PIXEL_SIZE for the map determines if layer appears. Map pixel size must be less than this value for the features to be displayed.
  • FILTER sets the MTFCC categories to use.
  • LINE_WIDTH, LINE_COLOR determine line characteristics.

MTFCC is "MAF/TIGER Feature Class Code".  It has a letter for the major category, and then 4 numbers for subcategories.  The XML metadata file with each shapefile defines the codes.

- <edom>
  <edomv>H3013</edomv>
  <edomvd>Braided Stream</edomvd>
  <edomvds>U.S. Census Bureau</edomvds>
  </edom>

 

MICRODEM selection form

This window allows modifying the plotting parameters with TIGER data. This can be activated by right clicking on a map with TIGER data displayed, or on the Vector Map tab of the options form

  • Separate tabs control the roads, political boundaries, other features, auto-scaling, and file options.
  • The check box determines if the feature is plotted or not.
  • The buttons control the line width, and the line color for each feature.
  • Auto appear scaling uses "smart" logic to remove smaller features as the map scale becomes smaller. See an example of TIGER smart scaling.
  • When autoscaling is on, the roads and streams only appear if the pixel size on the map (in meters) is smaller than the selected threshold.
  • Label every record
  • Defaults returns all settings to the program defaults.

 

Roads tab

TIGER uses 7 levels of roads, from interstates to trails.  The TIGER shape files use only 6 levels of road, (combining levels 2 and 3 into one).

Boundaries tab

TIGER has political boundaries, which are generally not very useful.

Others tab

The "Feature Labels" determines whether roads and streams will be labeled.

The TIGER shapefiles use only 1 water level.

Powerline and Pipeline are not used very often or consistently.

Feature labels determines whether text labels will be drawn.  You must be really zoomed in to avoid solid text layers.

Autoscaling tab

These shows the size in meters of the map pixel when features will appear. Notice that a small scale map, with large pixels covering a large area, will only show the most important features.

Features can be labeled, but it is likely that every block will be labeled because of the way the TIGER files are organized.

Files tab

If you set Auto appearing on Maps, or select the Overlay, All TIGER, you can set the max number of counties to automatically draw.  If your map has more than this number, you will be asked if you want to proceed.  To avoid that annoyance, set this number high.  On the other hand, if you sometimes open very large DEMs, you might not want to open all the Tiger files that cover it, and would instead want to use data from the US National Atlas.

he use of zipped files, and the use of the old ASCII files, are probably not working and are not likely to return. 

 

Overview of TIGER operations, and sample output.

 

TIGER Shapefile record.

 


Last revision 6/5/2016