CTPP 2000 Part 3 GIS-based Online Query Help

NOTE: In order to maintain the performance of the application at a reasonable level, the maximum number of records of a query result to be displayed is set at 1,000. If a query generates more than 1,000 records, the query result will NOT be displayed in any forms (table, chart and map). However, the query result can be downloaded directly onto the user's local PC.

Basic Steps for Using the CTPP 2000 GIS-Based Online Query Application

The primary purpose of the CTPP 2000 GIS-Based Online Query Application is to make the query of the Journey to Work related data in the CTPP 2000 database easy, intuitive, and with visual aid. While there are many ways to achieve the same results, a query in the application always involves three major sequential steps.

Step 1 - Select Residence and Work Areas for a query at a specific summary level.
Step 2 - Decide the information to be queried from CTPP tables.
Step 3 - Decide how to display the query result.

The application offers two tools to assist the user to select Residence and Work Areas for a query. One is Text Selection, which is a conventional dynamic web interface that allows the user to decide the level of geography (State, County, Place at State Level) for the query, select Residence and Work Areas of interest, and select the data to be queried (the CTPP 2000 tables and variables). This interface is dynamic because Residence and Work Areas available for selection are dynamic decided by the user's selection of the level of geography at which the query result to be displayed.

The other tool is Map Selection, which is a GIS-aided dynamic interface and allows the user to select Residence and Work Areas of interest directly from a map. With this tool, the user starts a query by deciding the level of geography (State, County, County Subdivision, Census Tract, etc) for the query and by selecting a "Selection Tool" from the GIS Tool Bar of the interface (by a single click on the tool) to be used for selecting. Once these two decisions are made, the user can select (and reselect) the Residence and Work Areas of interest by clicking and dragging on the map.

Except that the level of geography for the query and Selection Tool to be used for selecting need to be decided first, the order at which selections are made, including order of selections of Residence and Work Areas, does not matter. Only the current selections will be used to display the query result. Once the Residence and Work Areas are selected, the user can go to "Variables Selection' page to finish up the query process and decide how to display the query result.

The more familiar the user is with the GIS Tools available in this application, the more effectively the user can take advantages of the Map Selection. The following table presents information on how to use each of the available GIS Tools in this application.

Icon	Tool Name	Function
	Show Legend	A single click on this icon to show map legend in a new window. top
	Zoom In	When this icon is selected, clicks on the map will "zoom in" the map view, centered on the clicked position. top
	Zoom Out	When this icon is selected, clicks on the map will "zoom out" the map view, centered on the clicked position. top
	Zoom to Full Extent	When this icon is selected, a click on the map will zoom the map view to the full geographic extent of all layers combined. top
	Zoom to Active Extent	When this icon is selected, a click on the map will zoom the map view to the full geographic extent of the active layer. top
	Zoom to Last Extent	Clicks on this icon will toggle between the current extent of the map view and the previous extent. top
	Pan	When this icon is selected, left-click on the map and hold to drag the map around to show different parts of the map on the screen. This tool is particularly useful when the extent of the map is larger than the computer screen. top
	Query	A click on this icon will bring up an "interface area" at the bottom of the map view to allow the user to construct queries about the active layer. To construct a query: 1. Select the query criteria from Field, or Operator, or Value, or the logic operators. 2. Click on the "Add to query string" button to add your selection to the query string you are constructing. 3. Click the "Execute" button to execute the query you have just constructed. top
	Find	A click on this icon will bring up an "interface area" at the bottom of the map view to allow the user to find a specific string of text in the underlying data of the active layer. top
	Select by Buffer	When a selection (either a point or an area) has been made on the map, a click on this icon will bring up an "interface area" at the bottom of the map view to allow the user to create a buffer on the map around the selection according to the parameters provided through the interface by the user. If the "Display Attributes" option is selected, "Create Buffer" will also display the data/information available for the feature(s) selected in a table at the bottom of the map view. top
	Select by Circle	When this icon is selected, the user can select the geography units of the active layer by drawing a circle on the map. The center of the circle is determined by a single left-click on the map and the radius of the circle is specified by the user through the "interface" which would show up at the upper left corner of the map view when the "Select by Circle" icon is selected. All geography units touched by the circle will be selected. Selected areas are highlighted, and data/information available for selected areas is displayed in a table at the bottom of the map view. top
	Select by Line/Poly	When this icon is selected, the user can select the geography units of the active layer by drawing a line or a polygon. A line or a polygon can be drawn by left-clicking on the map and then clicking on the "Complete Line & Select" or the "Complete Polygon & Select" button in the "interface" at the bottom of the map view. The "interface" appears when the "Select by Line or Polygon" icon is selected. All geography units touched by the line or polygon will be selected. Selected areas are highlighted, and data/information available for selected areas is displayed in a table at the bottom of the map view. top
	Select by Point	When this icon is selected, the user can select the non-adjacent geography units of the active layer one-by-one by left-click on them on the map. The user can also select a group of adjacent geography units by left-click (and hold) and drag. All geography units touched by the rectangle will be selected. Selected areas are highlighted, and data/information available for selected areas is displayed in a table at the bottom of the map view. top
	Clear Selection	A click on the icon will clear currently selection(s) from the map. However, it will not clear the list of selections for the query. top
	Print	Click on this icon to create a printer-ready page of the current map view on the screen and its legend with preformatted map layout. Enter a title for the map through the Title Box at the bottom of the map view and click on the Create button to create the printer-ready page. Use your browser's print function to print the map. top
	Overview Map	Click on this icon to toggles the overview map on and off. This tool helps the user to see the location of "zoom in" area on the map. The user can also move the red box within the Overview Map to view interested area in the map view window. top
	View/Refresh the Selected Areas	Click on this icon will zoom the map view to the optimal extent to allow the user to view all the selected area at once. It will also refresh the list of the selected areas in the left-side bars if any selected areas have been removed from the selection. top
	Deselect Selected Areas	Click on this icon will deselect all selected areas from the map and clear the list of selected areas in the left-side bars. top