This section shows how to create a census tract thematic pattern map. The state of Texas by census tract shapefile, included with installer, is used as an example.  A similar set of steps could be used to develop a state by county thematic map, among many other different geographic structures.

 

Requirements: any version of CVGIS (saving the resulting project requires Level 1 or higher)

 

Start CVGIS with the default project. This is the project that automatically opens when CVGIS is installed.

 

The steps are:

1. decide on a design for the thematic pattern to be displayed

.. Texas by census tract showing population ages 0 to 9 years of age.

2. add a new layer (Texas by census tracts)

.. this will the layer used to display the new thematic pattern.

3. reposition/drag the new layer in the legend panel

.. so that it shows with the preferred set of layers above and below it

4. use the layer editor to add sections/intervals and assign color/patterns to different population ranges

 

Here are step by step instructions:

1. decide on a design for the thematic pattern to be displayed

.. Texas by census tract showing population ages 0 to 9 years of age.

2. add a new layer (Texas by census tracts)

.. click File>AddLayer; in the dialog box open the file "cb_2014_us_tracts_500k_acs1014_48.shp"

.. the new layer appears at the top of the legend panel. The map window shows the layer with gray fill pattern.

3. reposition/drag the new layer in the legend panel

.. right click on the layer name of the new layer,

  hold mouse button down

  drag the new layer down in the legend panel to the position above the layer $MHI x Tract

  release the mouse button.

.. place the new layer anywhere, it is a matter of choice and design

4. use the layer editor to add sections/intervals and assign color/patterns to different population ranges

.. dbl-click the layer name (cb_2014_us_tracts_500k_acs1014_48..) starting the layer editor.

.. the layer editor form immediately opens, click the Section tab (at top of form).

section/interval 1

.. next add a query in the edit box under "Render if match query"

.. the query should be "(d004+d005)>=500" (no quotes); copy and paste the text or key it into edit box

.. this says to display all tracts that meet this criteria according to the color pattern setting in the Area Tab

.. click the Area Tab and set the color to blue

add section/interval 2

.. next add a query in the edit box under "Render if match query"

.. the query should be "(d004+d005)>=250 and (d004+d005)<500"); copy and paste the text or key it into edit box

.. this says to display all tracts that meet this criteria according to the color pattern setting in the Area Tab

.. click the Area Tab and set the color to yellow

add section/interval 3 (others could be added, but stop with three intervals for this example)

.. next add a query in the edit box under "Render if match query"

.. the query should be "(d004+d005)>=0 and (d004+d005)<200"); copy and paste the text or key it into edit box

.. this says to display all tracts that meet this criteria according to the color pattern setting in the Area Tab

.. click the Area Tab and set the color to red

click OK button at top right on the layer editor form.

 

The map window now shows the desired result.

 

What are D004 and D005 and why were they selected?

 

As shown in the tract layer metadata (part of the documentation for the spart-up project)

D004 is the field name for "Sex and Age -- Total Population -- Under 5 Years"

D005 is the field name for "Sex and Age -- Total Population -- 5 to 9 Years"

 

these fields are added in the render query to define the criteria for data display.

 

This completes this tutorial.