The Data Engine software (also known as Allocate or SRC) included with the 2000 Census CDs and DVDs is very powerful and useful. In addition, users can get data for a large number of areas (such as blocks or block groups) more easily than with American FactFinder.

Install options

1. Use with CD/DVD
   • You can load just the software and run it with the CD in the CD drive, a good option of space is at premium.
2. Use without CD/DVD, e.g. install all the data on to your hard drive.
   • The CDs will require up to 650 mb of hard disk space.
   • The DVDs require upwards of 100 times as much space. The SF1 data takes 7 gigabytes of space.

Workspace

The workspace directory retains the parameters of your session and thus saves time if you routinely need data for the same geography or data item.

1. To name a Workspace using the default directory for storage, type the name of the file in the space
2. Proceed to the Save As... button.
3. Custom queries, while useful, are tedious to create and require workspace files.
4. Workspace files are just text files and can be modified outside of Allocate in standard text editors. Users can also control the order in which the variables are listed this way.
5. A sample workspace file with comments follows. The naming convention is "somename.aws".

Line of Code	Comments
;Census 2000 Data Engine Workspace File	The leading semi-colon is not a typo; this line must be present.
UsingDataSet(US_SF1)	You can change this as needed (e.g. MN_SF1)
Geography(SumLev040,27)	You can change this as needed - see these lists of summary levels.
Output(File,C:\TEMP\save\single_year_age2.xls,8)	You can specify the directory in which your file will go here.
OutputSummary(False)	Change to True if you want one.
Formula(Total_Under_Five,[P012003]+[P012027],False)	The formula lists the new variable name, the data dictionary reference names and the mathmatical operators. You can ignore the "False" here.

Pick Geography

• Clicking in the radio box in front of the geographic level will select all areas at that level. For example, if the level is Census Tract, then clicking on it will select all of the tracts on that disk. That means that if you're using the SF1 DVD, you will have selected every tract in the United States.
• To select areas within a level, click on the name of the level or on the + sign, which will display all areas in that level.
• Continue clicking until the areas desired are displayed, then click in the box to select those areas.
• If you inadvertently choose a very large number of areas the first hint will be a very long processing time.
• If that happens, the software allows you to cancel, and return to the geographic selection menu and refine the selections.

Custom Radii

This option under Pick Geographyallows aggregation of data for a circle defined by a radius centered on a point defined by latitude and longitude.

• If you don't know the latitude and longitude of the center of the area, selecting Internal Point (latitude) and Internal Point (longitude) will give you that information.

1. Enter the latitude and longitude into the Add Radii box,
2. Continue by filling in the radius or radii if you want, since you can choose more than one.
3. Enter a name for the place by highlighting the latitude and longitude in the Point Name box.

A doughnut can be specified that is from 1 to 3 miles from the center.

1. In the Radii or Doughnuts box enter 1-3 for 1 to 3 miles. Units can be in Miles, Kilometers or Drive Time (Minutes) - use the pull down menu to select the units.

Output

This menu item is for selecting the form in which the data will be generated.

• HTML reports are the default and can be generated using pre-formatted report options or a blank report.
  • The blank report allows users to select variables to include in the report.
  • With the pre-formatted reports, variables are pre-selected.
    1. To view the titles of the reports, click on browse and a screen will appear with folders for Detailed Tables and Quick Tables.
    2. Click on the folder icon to see the contents of these folders
       (for Detailed Tables there will be three folders for Housing (H), Population (P) and Population-Census Tract (PCT) tables)
    3. Opening the folders will bring up the titles of each table which you can then read.
    4. Click on the title to select that report.
• Files of the formats .dbf, .xls, .csv and .mdb and .html may also be chosen.
  1. Click the radio button for File
  2. Click the Save As button
  3. Choose a name, format and location to save.

Simple Variables

1. To select variables from the file, simply click on the headings and continue clicking until the actual variables appear.
2. Then click on the variables or highlight them and click select. Selected variables appear in the Output Variables box on the upper right of the screen.
3. If you want to map the data, select Geographic Variables to match the geographic level you chose under Pick Geography.

Custom Variables

This option allows users to calculate rates or percentages, sums, etc.

• When the Custom Variableoption is selected, a box appears with a series of operators, a Formula box and a New Variable Namebox.
• Highlight the variables for the formula and click on VAR to select variables and click on the appropriate operators to generate the formula.
• When the formula is complete, give the custom variable a name in the New Variable Name box and click select to add it to the variables listing.

Finishing

• When all selections have been made (and you probably want to look at what is in the Output Variablesbox to be sure), click Finish to complete the process.
• If you are generating an .html file, the software will ask you if you want to open the file with the system default applicationor a specific application. System Default Application means the default browser on the computer you're using. Unless you have specific reasons for doing otherwise, just choose this option.
• If you generated another file type, you will be offered the same options as well as the option of opening the field descriptions file. The latter gives the names of the variables as well as the description of each variable, e.g., TRACT, Geographic Identifiers 2000 Census Tract. To open the file, the same options will be shown as with .html files.
• To include the descriptions from the descriptions file, look in the same directory for a file with the same name (e.g., test.xls) but with .desc.txt appended to the name (test.xls.desc.txt). This file will be generated with each file and can be opened as a comma delimited file in any spreadsheet program.

Mapping

• A key variable will be generated with every non-html file.
• The key variable is sometimes the same as the geocode needed to map the data, but not always.
• To generate a geocode, the best option is to select geographic variables as described above.
• If you are using ArcView or ArcInfo, the GIS software will allow users to concatenate the codes into a geocode to facilitate mapping.
• If the codes in the data are text variables, simply concatenate the strings.
• If the codes are numeric, you may have to include a multiplier to generate enough place holders in the concatenation process - as covered under American FactFinder Mapping.