SDViewer -- Creating Project Files
SDViewer start-up is controlled by three GIS project files (GPRs), one for the contiguous states (sdus.gpr), one for Alaska (sdak.gpr), and one for Hawaii (sdhi.gpr). The three GPR files establish the view that appears in the map windows. Project files are used to automatically open map files that enable viewing certain types of geography, subject matter data, and viewing attributes of each. This section describes how to create a SDViewer project file so that other layers can be added to an existing project.
A portion of the default SDUS.GPR is shown in this popup window. There are nine layers in the default project. This section of the GPR shows only a part of the 9th layer ([R0001GIS Layer9]) and the overall project statements ([R0001GIS]).
Adding a TIGER/Line File. Suppose that you have used the GetWebGeodata to download the TIGER/Line file for Bexar County, TX (state FIPS code 48 and county FIPS code 029). In the SDViewer folder, there are actually 5 files used by SDViewer for the Bexar County TIGER/Line fileset:
To reference these collective files to SDViewer, only the TGR48029.RT1 file name is used. But, it is essential that all five files exist in the SDViewer folder.
To add this TIGER/Line file to a new project, a new layer description is added following layer 9. The layer numbering must be sequential with no gaps. Exact spelling and syntax are required. The exact syntax for the additional lines in the GPR are shown in this popup window. Additional layers of this type may be added.
Naming the New GPR Files. It is suggested that the new GPR be named sd48029us.gpr (upper or lower case will work, to maintain consistency, lower case is recommended). Copy the file sdak.gpr to sd48029ak.gpr. Copy the file sdhi.gpr to sd48029hi.gpr. These three GPRs must be in the SDViewer folder.
After the project files are created, they are opened using the File>Open Project operation. There is a special rule about project file naming. If the contiguous states GPR is ???us.gpr, then the Alaska GPR must be named ???ak.gpr and the Hawaii GPR must be named ???hi.gpr.
There are many rules about project file content/structure, reviewed elsewhere. But a key one is that all school district layer names must exist in the same manner as specified in the default structures.
Viewing the New GPR. Start SDViewer and select File>Open and then open c:\sdviewer\sd48029us.gpr. Zoom to the Bexar County, TX area and the view should appear as shown below.
The above GPR specification might be useful if zooming to a specific school or neighborhood.
Census Feature Class Code. Note the query line in the sd48029us.gpr. This statement:
Query=((CFCC like 'A1%') or (CFCC like 'P1%'))
selects only those line segments which have Census Feature Class Codes with corresponding values. See the CFCC descriptions for a list of other codes to select -- and view different types of features.
Remove the semicolon at the start of the line (before the word Query in the query statement) and save the file. Opening the revised GPR generates this view (Interstate highways):
Adding the county boundaries would be a useful layer for this type of view.