13 chapter 2 whirlwind tour: a field trip …apollo.umenfa.maine.edu/sfr400/inside mapinfo...

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CHAPTER 2

WHIRLWIND TOUR:A FIELD TRIP WITHMAPINFO PROFESSIONAL

As MENTIONED EARLIER, GIS TECHNOLOGY INTEGRATES graphic and tabular data and makes possiblethe simultaneous analysis of disparate data. To demonstrate the power of MapInfo Professional, a typical businesssite selection problem and GIS solution are presented in this chapter. The following series of tutorials permits you toparticipate in a real-world MapInfo analysis from beginning to end.

Do not worry if the pace seems a bit hectic, this is just an overview of the program. The rest of the tutorial (chapters3 through 12) examines in detail all MapInfo functions covered in this sample project.

Locating Satellite Pediatric and GeriatricClinics in San FranciscoAssume that San Francisco county administrators want to reduce patient loads on existing hospitals. Becausechildren and senior citizens visit the hospitals more than other age groups, planners decide that specialty clinics forthese two age groups would be the most useful measure toward relieving overburdened hospitals. The targetpopulation for geriatric clinics is age 55 and over,

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Chapter 2: Whirlwind Tour: A Field Trip with MapInfo Professional

whereas the target population for pediatric clinics is under age 18. For purposes of this exercise, you will assumethat no pediatric or geriatric clinics currently exist in San Francisco County.

Although this satellite clinic location problem is hypothetical, it readily lends itself to a GIS-based solution. Theprimary objective is to establish satellite clinics in areas where large numbers of prospective clients reside.

Data Overview

You will use data table files provided in the “Samples” folder found on the NSFA server for the following series oftutorials. The files are listed in table 2-1, which follows.

Table 2-1: Companion CD-ROM Files Used for Chapter 2 Tutorials

File Name Description

SF_GROUP.tab U.S. Census Block group boundaries; the geographical unit used in the analysis.

SF_STRTS.tab Street file in graphic format to display on the San Francisco map. This file will beused near the end of the analysis, when you are ready to locate a site.

SFGTRL00.tab Demographics to be used in conjunction with the block group boundaries to

identify potential clinic sites.

SF_LANDM.tab Hospital information to be used for excluding certain areas from consideration.

SF_BAY.tab Adds a blue background for the bay shown on the map.

Sf_BACK.tab Background color for the base map.

Some of these table files are graphical and others are tabular. When you open a tabular file, you see data organizedin tabular form. MapInfo Professional refers to such tables as browsers. When you open a graphical table, you willsee graphical data displayed on a map as points, lines, or regions (areas, or polygons).

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Identifying Potential Pediatric Clinic Sites

Procedural Outline

The following is an outline of the procedures you will pursue to identify optimum sites for the pediatric and geriatricclinics.

! Define the target population.

! Buffer existing hospitals to locate unsaturated areas.

! Visually scan areas for potential sites.

! Perform radial queries.

! Perform statistical analysis.

Identifying Potential Pediatric ClinicSites

The first step in identifying potential sites is to define the target population. Pediatric clinics should belocated in areas containing a large population of children (people under age 18). In contrast, the geriatricclinics should be located in areas containing a large population of people age 55 and over. Next, ideal targetlocations for both types of clinics are densely populated areas, such as downtown San Francisco. Finally,the clinics should be located in areas of stable or increasing population growth. The analysis will be basedon the 1998 estimates in the demographic data file.

NOTE: It is recommended that you create a new subdirectory on your local drive for storage ofthe files created during tutorials and exercises in this book. Use the File Manager to create thenew subdirectory. For the subdirectory name, you might use Tutorials or Exercises.

To begin this series of tutorials, perform tutorial 2-1, which follows.

TUTORIAL 2- I: OPENING FILES TO BEGIN A PROJECT

1. Click on Open > Table from the drop down menu or the open icon at the top of the menu bar, and “Filesof type: MapInfo (*.tab)

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2. The Open Table dialog box, shown in the following illustration, displays drives, directories, and file names.Select the samples directory on the Network drive “N:\class_folders_web\SFR400\Samples”.

Open Table dialog box.

3. To open the files you need, click on the icon, Table for each of the following file names: , SF_STRTS,SF_LANDM, SF_BAY and SF_BACK. Be sure to select Preferred View : Current Mapper before choosingOpen

TIP 1: Similar to most other Windows applications, in MapInfo Professional you cansimultaneously open multiple files by one of two methods. If the files you want to open aresequential, hold down the <Shift> key and click on the first and last files. MapInfo will open thefirst and last files and all files between. If the files you want to open are not sequential, hold downthe <Ctrl> key and click on the desired files.

Tip 2: Selecting items in MapInfo Professional is consistent with selecting items in Windows. Toselect an object, simply point the mouse cursor at the object and press or click the left mouse button.

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After opening the five files, the map on your screen should resemble that shown in the illustration on theleft. To obtain the view on the right with your cursor on the map click your right mouse button choose“View entire layer” then choose SF_STRTS. This is explained in more detail in step 2-3 below.

Map resulting from opening five files.

If the map on your screen does not resemble this map, you need to reorder the map layers; that is, changethe drawing order of the map layers. MapInfo places each mappable (graphical) table in a layer, and assignseach layer a place in the map drawing order. The layer at the top of the list will be drawn last. For example,if the landmark layer (SF_LANDM) is below the block group layer () in the layer listing, the landmarks willnot be visible. Reorder the layers by performing tutorial 2-2, which follows.

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TUTORIAL 2-2: CHANGING THE DRAWING ORDER OF MAP LAYERS

1 “Explorer” is displayed along the left side of yourscreen. The Explorer dialog box, shown in theillustration at right.

2 Reorder the files as shown in previous illustration byselecting a layer, and dragging it up or down to thedesired location.

3 The layer(s) will move instantly as you release the leftmouse button.

Explorer dialog box.

If only a portion of the map is visible, or the map is not focused on San Francisco, perform tutorial 2-3,which follows.

TUTORIAL 2-3: ESTABLISHING THE LAYER VIEW

1 Click with your right mouse buttonany where in the map window.Choose View entire Layer...

2 Select the SF_STRTS layer fromthe View Entire Layer dialog,shown in the illustration at right.The screen will redraw.

View Entire Layer dialog box.

Hospital locations are part of the landmark table (SF_LANDM) opened previously. A hospital is depicted onthe map by a blue H enclosed in a white box. The next task is to isolate the hospitals from the otherlandmarks to simplify the analysis. To isolate the hospitals, you need to construct a query based on theSF_LANDM file. Tutorial 2-4, which follows, takes you through this process.

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TUTORIAL 2-4: QUERYING TO ISOLATE LAYER ELEMENTS

1 From the main menu bar select Table > SQL Select.This will open the SQL Select dialog box, shown inthe illustration at right. Select the SF_LANDM thetable from the Tables on the right side of the dialogbox. The name of the table should appear in the"from Tables" box.

2 Click inside the box next to the “where condition”box. Next, select class from the Columns list. The“class” column is inserted in the “whereCondition:” box.

3 Position the cursor after the word class and select“=” from the Operators list and type the wordhospital enclosed in double quotes ( = “hospital”).

4 Click on the Verify button at the bottom of thedialog box to ensure that the syntax of the querystatement is correct.

5 Verify that the Browse Results option (lower left) is activated. If a check mark appears to the left of BrowseResults, the option is activated.

Click on OK to issue the query statement. MapInfo Professional will process the query statement, highlight allhospitals on the map, and open a Browser window containing a list of the hospitals. The results of the query willbe placed in a temporary table named Selection.

TIP: You can access query results at any time during the current session by noting the querynumber at the top of the resulting Browser window, selecting New Browser at the left of yourtool bar, and selecting the appropriate query number from the list.

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At this juncture, you will save the query results as a new file. Although MapInfo can work with and save temporary

tables (i.e., query results), for the purpose Of this exercise you will work with saved tabbies. Tutorial 2-5, whichfollows, takes you through this process.

TUTORIAL 2-5: SAVING QUERY RESULTS AS A NEW FILE

1 Select TABLE > Save Copy As from the main menu bar. The following illustration shows the queryresults and the Save Copy As dialog box.

The Query1 Browser list of hospitals and the Save Copy As dialog box.

2 Select the “Query1” from the list.

3 Click on the “Save As” button to access theSave Copy of Table As dialog box, shown inthe illustration at right.

4 Now you need to name the file containing thehighlighted hospital landmarks and store it inyour Exercise or Tutorials directory that youcreated earlier on your local D: disk. UnderFile Name, type in Hospital as the name ofthe new table you are creating.

Save Copy of Table As dialog box.

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5 Click on OK to save the file.

6 To add the new hospital.tab table to the map, select Open Table from the main menu bar, and then selecthospital. Verify that the Preferred view is “Current Mapper”

7 To remove the SF_LANDM table from the map and eliminate the overlap with the hospital table, Select theSF_LANDM layer then choose the “X” from below the Explorer tab . Choose yes to the question “Areyour sure you want to remove the selected Layer?” The screen will redraw.

At this point, you may need to reorder the map layers. Continue with the following steps.

8 The layers may be reordered under the Maps tab in the Explorer window.Reorder the files as shown in theprevious illustration by selecting the Up or Down arrows at the top of the dialog box or dragging theselected layer up or down. The map will be redrawn instantly.

Maps Dialog Box

9 To change the color of the SF_GRUOP (these are Census Blocks for San Francisco) Double click on iconjust to the left of the words “SF_GROUP” and change the “Foreground:” color to H-2 and the “BorderColor:” to M-1. Change the Width to Pixels “2". Then choose “OK”

The map view on your screen should now resemble that shown in the following illustration.

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Map view showing reordered layers.

Buffer Hospitals

All files required to begin the analysis are in place. Now you will identify the competition. In the absenceof pediatric clinics in San Francisco, the only competitors are existing hospitals. Because you do not wishto locate a new clinic within a half-mile of an existing hospital, you will place a half-mile buffer around thehospitals. To place the buffers, you need to return to the Explorer >Maps dialog box to make the cosmeticlayer editable. Tutorial 2-6, which follows, takes you through the process of placing buffers.

• TUTORIAL 2-6: PLACING BUFFERS

1 Explorer > Maps.

2 Highlight the cosmetic layer at the top of the layer list in thedialog box.

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Buffer Hospitals

3 Select the pencil icon to make the cosmetic layer editable. Choose the “Select Arrow” from the main menubar

4 Next you will write a query to select all hospitals and then create buffers around these objects on the map.Continue with the following steps.

5 Choose TABLE >SQL Select from the main menu bar. The previous query you created should appear.

6 Change the name of the table to hospital (from SF_LANDM), deselect the Browse results (remove the checkmark in the lower left corner), and click on the OK button (see the following illustration for help, whichshows the SQL Select dialog box with the proper syntax). All hospitals on the map should becomehighlighted.

SQL Select dialog box.

7 Now you are ready to create the buffers. Select “Spatial” from the main Menu Bar. Then select “Buffers >Buffer Objects” to access the “Buffer Objects” dialog box.

NOTE: If the Buffer option is not enabled, you need to verify that the cosmetic layer is editable. SelectExplorer > Maps and proceed, as explained previously.

8 Visually look at the map to ensure that all hospitals are still highlighted (selected) by clicking on the mapwindow's title bar. If all hospitals are not selected, repeat steps 5 through 7. Click anywhere on the BufferObjects dialog box, shown in the following illustration, to continue.

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9 Duplicate the settings in the Buffer Objects dialog box, shown at right.Make sure you select 0.5 as the radius Value (for a half-mile radius).Verify that Units are set to “miles” and the "One buffer for eachobject"option. If you select "One buffer of all objects," MapInfo willautomatically merge any buffers where they overlap. Set “Smoothness:40"

10 Click on OK. The map on your screen should redraw to resemble thatshown in the following illustration. The buffers are highlighted withhatch patterns.

Buffer Objects dialog box.

Map of San Francisco with highlighted half-mile buffers around the hospitals.

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Buffer Hospitals

With the buffers in place, you can quickly and easily view the areas where new clinics cannot be located. Inorder to use these buffers throughout the analysis, you will save them as a new file. Tutorial 2-7, whichfollows, takes you through this process.

TUTORIAL 2-7: SAVING BUFFERS AS A NEW FILE

1 From the Main menu bar, select Map > Cosmetic> Save Cosmetic Objects.

2 Save the newly created area buffers to a new table named buffer. Todo this, select “New” then “Save” under “Save Cosmetic Objects”dialog box. This will open the “Save Objects to Table” dialog boxwhere you will enter “Buffer” as the file name and then “Save”.This file will be automatically added to the current map.

3 You will probably need to reorder the layers again so that thehospitals will appear on top of the buffers. (Select Explorer > Mapsand move hospitals up to ensure that the hospital table appears abovethe buffer table in the layer listing.)

Save Cosmetic Objects dialog box.

4 You are now ready to identify potential sites for the clinics; that is, areas with a high concentration ofchildren. Continue with the following steps.

5 Select Table > Open > Table from the main menu bar.

6 Select the SFGTRL00.tab file located in the Samples folder . Because this file contains tabular data, the dataappear in a Browser window, rather than a graphic window.

7 Scroll across the top row of the Browser to examine the data available in the SFGTRL00 file. Populationage group information appears in columns to the far right. The block group name is called ID in this table.The ID column will permit you to link the tabular data in this file with the boundaries file (SF_GROUP)opened previously. A portion of the browser window is shown below.

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To close the Browser and return to the map, click on the X in the upper right corner of the Browser window, shownin the following illustration.

Partial Content of the SFGTRL00 file as seen in Browser window.

To identify potential sites, you will create a thematic map depicting the concentration of the target group:residents under age 18. The SFGTRL00 file does not contain a column titled "below 18." An expression forselecting this age group must be created when defining the thematic map. To create the thematic map,perform tutorial 2-8, which follows.

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Buffer Hospitals

TUTORIAL 2-8: CREATING A THEMATIC MAP

1. Verify the active window is the Map window. Select “Map > Add Theme” to open the “Create ThematicMap” dialog box. (Note the Map window must be active for the dialog box to open). The Step 1 of 3 dialogbox appears, shown in the following illustration. Note that “Region Ranges Default” has been selected.

First dialog box in the Create Thematic Mapseries.

2. Select Ranges as the type of thematic map to create, and Region Ranges Default as the template.

3. Upon selecting a type of thematic map, click on the Next button,and another dialog box appears. In this dialog box, shown in theillustration at right, you will select the block group(SF_GROUP)table from the drop down menu as the table to beshaded for the thematic map.

4. Scroll through the Field list, and select Join. (The Join selection isnear the bottom of the list.)

Second dialog box in the CreateThematic Map series.

5. Selecting Join activates a dialog box that prompts you for the name of the table to join to . Select theSFGTRL00 table, and then click on the Join button.

6. Duplicate the selections in the Specify Join area, as shown in the following illustration. In other words, jointhe tables through the BlockGroup field in the table with the ID field in the SFGTRL00 table, and thenclick on OK

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Update Column for Thematic dialog box showing join fields fortables.

7. From the Update Column in the Thematic dialog box, select Expression by clicking on the drop downarrow adjacent to “YCOORD” and moving down to the very bottom of the list. At this point, theExpression dialog box appears. To create the expression for the population under 18, sum the followingfields in the SFGTRL00 table.

•TPA98_0_4•TPA98_5_9•TPA9810_14•TPA9815_17

TPA represents "Total Population Aged," and 98 represents1998 population estimates. Next, 0_4, 5_9, 10_14, and15_17 represent age groups. To create the "under age 18"population group, simply add the values in the four agerange fields. See the next page for the sample expressiondialog box with the properly constructed expression.

8. In the Expression dialog use the Column and Operatorbuttons to create the expression, do not attempt typing thesevalues as you may likely create an expression error . Tofind the expression go all the way to the bottom of the dropdown list as shown to the right.

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Buffer Hospitals

Expression dialog box showing the expression for adding thefour age groups.

9. Click on the tow OK buttons to return to the Step 2 of 3 dialog box, and then click on the Next button tocontinue. At this point, the Step 3 of 3 dialog box appears (shown in the following illustration), which willallow you to customize the thematic map prior to implementation.

Third dialog box (Step 3 of 3) in the Create Thematic Map series usedfor presenting data selected in expression.

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First, you will customize the ranges for the proportions of the population age 18 and under.Tutorial 2-9, which follows, takes you through this process.

• TUTORIAL 2-9: ESTABLISHING RANGES

1. In the Step 3 of 3 dialog box, click on theRanges button.

2. In the Customize Ranges dialog box, shownin the illustration at right, select Custom asthe range Method.

3. Change # of Ranges to 5. The Recalc buttonappears at the bottom of the dialog box.Select Recalc and the five ranges will appear.

4. Define the ranges, as shown at right, byentering the maximum and minimum valuesfor each range. Use the following ranges: 1-250, 250-500, 500-750, 750-1000, and 1000-2220. These ranges were selected afterviewing the initial ranges automaticallydefined by MapInfo Professional.

Customize Ranges dialog box.

After entering these ranges, select the Recalc button to calculate the percentage and count of Block Groupsthat fall within each range. Select OK to return to the Create Thematic Map - Step 3 of 3 dialog box. At thispoint, you can alter the appearance of the ranges on the map by selecting Styles (in this dialog box). The“Customize Range Styles” dialog box is shown in the following illustration.

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Buffer Hospitals

Customize Range Styles dialog box.

If you select the Color option under AutoSpread, and then click on the top region stylescolor box, range colors are changed from thecolor scheme of the chosen template to shades ofthe selected color. At this point uncheck“Replace Layer Style”, then you may select adifferent color or pattern for each range via theColor box. Select red to depict "hot spots" (areasof high concentration for the target market),orange for the second highest range, yellow forthe third range, green for the fourth, and blue for"cold spots" (areas of least potential). Note that“All others” are white and you may also changethat color. Click on OK to return to the Step 3 of3 dialog box.

You can also customize a range legend to improve the map's appearance by selecting Legend from the Step3 of 3 dialog box. To customize the legend as shown in the following illustration, perform tutorial 2-10,which follows.

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•TUTORIAL 2-I0: CUSTOMIZING A LEGEND

1. Click on the Legend button.

2. Change the title to Population Under Age 18.

3. Change the title font (click on the Aa box) to Times New Roman, 10 point, and italic.

4. Change the subtitle to in San Francisco. You may wish to add some blank spaces before “in” to center thetext under the title.

5. Change the subtitle font (Aa box) to Times New Roman, 8 point, and italic.

6. Change the ranges to reflect the fact that the values in each range are greater than or equal to (>=) theminimum value and less than (<) the maximum value. If the range is currently labeled 1-250, the actualinclusive range values are 1-249. Change all values, as shown in the following illustration, so that eachrange is transparent to your audience.

7. Click on the "All Others" range under Range Labels and then uncheck the Show this Range option so thatthis range will not appear in the Legend window.

8. Change the font for the Range Labels to Times New Roman, 8 point.

9. Select New Legend Window under the Into Window option. This will bring up the Customize Legenddialog box, shown in the following illustration.

Customize Legend dialog box containing suggested legend and range labels.

The following illustration shows the map depicting different concentrations of the population under age 18.To locate potential sites for a pediatric clinic, you can visually scan the map for hot spots, or highconcentrations of the target population. The dark areas (red in a color map) show high concentrations of theunder-18 population.

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Buffered Hospitals

Map of San Francisco showing relative concentrations of population under age 18 byblock group.

To locate potential sites for pediatric clinics on the new map, you will create a new table.Tutorial 2-11, which follows, takes you through this process.

•TUTORIAL 2-1 I: CREATING A TABLE FOR LOCATING SITES

1. Select Table > New Table from the main menu bar.

2. Select Add to Current Mapper in the New Table dialog box, shownin the illustration at right, uncheck Open New Mapper, and thenselect the Create button to start defining the table.

3. Define the table in the New Table Structure dialog box by using thefollowing columns: id_no, type, and potential_no. (See the followingillustration.) Type in id._no under Name to define the first field in thenew table.

New Table dialog box.

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Be sure to use the underscore character ( _ ) instead of a space between id and no because MapInfo Professionaldoes not allow spaces in field names. Select Character as Type, and set Width to 10. The field will now allow up to10 characters to be entered for each record.

4. Click on Add Field to define the next field. Under Name, key in type. Select Character as the data Type forthis field, and set Width to 15.

5 Click on Add Field to define the final field. Name this field potential_no. Set the Type for potential_no toDecimal, Width to 10, and Decimals to 0.

New TableStructure dialog box

6 Click on Create after all fields are defined. The table structure should update to resemble that shown in theprevious illustration.

7. MapInfo will prompt you for a table name. Name the file Sites in the Create New Table dialog box. Be sureto save this table to the appropriate directory on your hard drive.

The id_no column in the sites table allows you to assign a unique number to each site for tracking purposes.Next, the type column allows you to use this table for researching the area for sites of other types of clinics(e.g., geriatric clinics). Thus, you could place both pediatric and geriatric clinic sites in a single file. Finally,the potential_no column allows you to track potential clients within a one-mile radius of a particular site.The one-mile radius is the estimated trade area for each clinic. Alternatively, you could select block groupsindividually in a rectangular form or customized polygonal shape if you wanted to invest more time inprecisely defining the trade area.

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Buffer Hospitals

Once the Sites table has been defined, created, and saved, check Explorer > Maps to verify that the tablehas been added to the map layers and is editable (i.e., that the pencil icon for the sites layer is active; shownbelow). The Sites table should have been automatically added to the map and made editable. Next, click onthe Spatial Tab to invoke the Symbol Style tool from the Drawing toolbar drop down menu (shownbelow).

Explorer > Maps (left);Drawing toolbar withsymbol icon selected(right)

The Symbol Style dialog box, shown in the following illustration, prompts you to select a Symbol, Color, Size,Background, and Effects for the Sites table. Select yellow squares from the MapInfo 3.0 Compatible symbol set(which will disable background and effects options) to depict potential pediatric clinic sites.

Symbol Style dialog box.

Next, click on the Spatial > Insert > Symbol on the toolbar and select alikely hot spot from the map. A visual scan has helped you identify threepotential sites for initial investigation.

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Using the Insert symbol tool, Create the three potential sites on your screen, as shown in the following illustration,by clicking on the map in each location.

San Francisco map of three potential sites for pediatric clinics.

The yellow squares were placed on hot spots depicted by red on the map. The hot spot at the top of the mapwas not selected because of its proximity to two existing hospitals. In contrast, an area near the center of themap was selected, even though it did not show the peak range of concentration for the target population.

Assume you decide to investigate this location based on the number of block groups and the absence ofhospitals in the surrounding area. The analysis could have been approached from a population densitystandpoint by dividing the number of people in the target population by block group area for each blockgroup. Because MapInfo Professional provides an area function for such purposes, the thematic map for apopulation density analysis would have been just as easy to create as the one you are currently workingwith.

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Radial Queries

Radial QueriesAt this stage you will identify the absolute numbers of the target population associated with each potential clinic site.Before you begin, select Explorer > Maps from the main menu bar, and set the Selectable option (the pointer icon)for the Sites layer to Off. If Editable is active for the sites layer; it will automatically become inactive when theSelectable option is turned off. Maps dialog box is shown in the following illustration.

Maps dialog box showing Selectable option turned off for the siteslayer.

To calculate the number of people under 18 years of age, you firstneed to select the block groups within the one-mile trade area. Thisis done using the Spatial > Select > Radius Select tool on the mainbutton pad, shown at left. Tutorial 2-12, which follows, takes youthrough the process of selecting block groups.

Spatial button pad.

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•TUTORIAL 2-12: SELECTING BLOCK GROUPS

1. Click on the Radius Select tool (see the previous illustration).

2. Place the cursor on one of the sites, and click on this spot on the map.

3. While holding the left mouse button down, start to expand the ring. A radius indicator will appear in thebottom left corner of the status bar in the MapInfo screen.

4. Expand the ring to a 1.00-mile radius, as indicated in the lower left corner of the screen.

You have now defined the trade area for the new site. The selected block groups on the map will contain ahatch pattern to differentiate them from other block groups. (See the lower right portion of the map in thefollowing illustration.)

Left view shows 1-mile radius; Right view- Shaded pattern showing the selected block groups surroundingthe southern-central site within a 1-mile radius.

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Radial Queries

You can zoom in on the shaded area to more closely view the selected block groups. To zoom in, performtutorial 2-13, which follows.

•TUTORIAL 2-13: ZOOMING IN ON BLOCK GROUPS

1. Select the Zoom-in tool from within the Map tab on the Main toolbar.

2. Click and drag while hold the left mouse button, a rectangle around the selected block groups. The map willzoom in to the selected location, as shown in the following illustration.

Results of a zoom-in on selected block groups surrounding a potential pediatric clinic site.

With the close-up view of the trade area, you could easily make adjustments to the area. However, forpurposes of simplicity and consistency, use the block groups selected in the 1-mile ring as the trade areas.

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In a real-world analysis, adjustments to the trade area are virtually inevitable due to competition, terrain, streetnetworks, and so forth. To return to the complete San Francisco area map, click with the right mouse button andselect Previous View from the pull down menu bar.

Statistical Analysis

To obtain the count (total) of the target population, perform tutorial 2-14, which follows.

TUTORIAL 2-14: OBTAINING TOTALS

1. Select the Map tab > Map Tools > Statistics from the menu bar.

The resulting dialog box will appear showing the statistics of theselected blocks. You may have to expand the window to see allof the information (shown in the illustration at right). If thestatistics do not display, the block groups are no longerhighlighted (selected) on the map. Use the Radial Select tool toagain select the block groups within a 1-mile radius of the site.

Calculate Column Statistics dialog box.

2. You are interested in a sum of all persons under age 18 for each site. In this example, the site trade areacontains 12,342 people in the target population.

5. Repeat the steps for radial queries and statistical analysis for each site to calculate the total targetpopulation in each potential site's trade area.

6. Assign an identification number to each site (e.g., 1, 2, 3).

7. From the Column Statistics dialog box, record the identification numbers and the target populations foreach site on a piece of paper. The Column Statistics window is shown in the following illustration.

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Statistics and Map window of the selected blocks.

Once you have recorded the appropriate statistics for all sites, return to the Maps dialog box, and click onthe Selectable option (the arrow icon) for sites. At this point, you are ready to update the Sites table.Tutorial 2-15, which follows, takes you through this process.

TUTORIAL 2- 15: UPDATING A TABLE

1. From the Map tab, select the Map Tools > Info Tool (i button). This tool accesses a window that containsinformation on a selected object. The Info Tool window can also be used for updating data.

2 Select a site by clicking on it. The Info Tool dialog boxwill appear. Other layers that are selectable will also beaccessible via the Info Tool window. Select the siteslayer by clicking on the word sites in the Info Toolwindow, shown in the illustration at right.

3. In the blank information box that appears, enter theidentification number you assigned to the site, as well asits corresponding trade area potential (sum of targetpopulation).

Info Tool dialog box.

4. Repeat steps 2 and 3 for all sites until the trade area information has been updated for each site, as shown inthe following illustration.

5. Save the updated table Sites by choosing Table tab > Save > Sites > Save. This will save the edits made tothis layer.

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Info Tool dialog box showing identification number assigned tosite and trade area potential

You are now ready to prepare a hard copy of the map for presentation to county officials. Tutorial 2-16,which follows, takes you through this process.

TUTORIAL 2-16: PREPARING HARD COPY

1. Select the Layout tab > New Layout on the far leftof the menu bar.

2. Under the Layout tab select Map and at the bottomof the drop down list should a line containing all ofthe layers you have open. Select that line (in thisexample Sites, Hospital....SF_BACK Map).

3 If you cannot see the entire layout, or the map appearsin portrait mode in the Layout window, you need tomake some adjustments. From the Layout option on themain menu, change thezoom using Change Zoomuntil you can better see thelayout, or select the expandicon in the lower rightcorner of the layout frame .

4. To change the map to landscape mode, click on Page Setup from the main menu bar. Select Landscape tochange the page orientation.

5. To resize the map in the Layout window, click on a corner of the map and drag it to fill the whitebackground (which shows the printable area of the Layout window), leaving some room at the top for thetitle of your Layout. Do not drag the frame beyond the extent of the gray grid in the background as thisdefines the extent of the printable area.

6. To place the legend in the layout window select the legend frame and drag it to a blank area in the layoutwindow. In this example it could be moved to the lower left corner as shown in the following illustration.

7. To change the background color of the layout frame click on the legend frame with the right mouse button,choose Frame Properties > Style and select the desired colors and fill patterns.

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To add a title to the map, perform tutorial 2-17, which follows.

• TUTORIAL 2- 17: ADDING A TITLE TO A MAP

1. Click on the Text icon from the Layout tab and place a text frame on the layout. The text options becomeactive allowing for bolding, italics, font styles, etc. Select a font size of 24 points or larger for thisexample.

2. Choose a font style, in this example AR Delaney was used with a dark blue color.

3. Type in the text for the title. If you need to edit the text, double click on the title you have created and the text tools will become active. You may make additional changes to the text or its appearance. Thefollowing illustration depicts the Layout window created for potential pediatric clinic sites.

4. A frame may be added to the map by selecting the Frame tool from the Layout tab and inserting a boxaround the map window just inside the gray grid border. If the map disappears it is because the new framethat was added contains a solid fill pattern. Clicking the right mouse button choose a fill pattern and color.Then push the frame to the background using Send to Back and the map will appear with a frame aroundthe border.

Map layout forhardcopy output ofpotential pediatricclinic sites.

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Chapter 2: Whirlwind Tour: A Field Trip with Maplnfo Professional

In the event you wish to change the map at a later time for presentation purposes, it would be wise to savethe current session as a workspace so that you can quickly return to the present Map and Layout windows.Opening a saved workspace will open all files that were open at the time the workspace was saved, as wellas the thematic maps, labels, cosmetic objects, query results, and window settings. To save the workspace,select Home > Save Workspace from the menu bar. The Save Workspace window is shown in thefollowing illustration. You may save workspaces frequently to save different stages of your work.

Save Workspace window.

Identifying Potential Geriatric ClinicSites

The location analysis for geriatric clinic sites can be conducted in the same manner as the analysis ofpediatric clinic sites. The target population for geriatric clinics has already been defined as the 55-and-overage group, and the buffers have been created around existing hospitals. At this point, you would create thethematic map for a visual scan of potential geriatric clinic sites. Select Map > Add Theme from the menubar. Click on Ranges as the type of thematic map. Create an expression for the population over age 55 byadding all age categories 55 and above.

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Identifying Potential Geriatric Clinic Sites

You are encouraged to follow the same steps used in the location analysis of potential pediatric clinic sites.You could execute this analysis now, or after you have studied subsequent chapters. The followingillustration shows the final results of the analysis aimed at identifying four potential geriatric clinic sites.

Completed map for hard-copy presentation of potential geriatric clinic sites.

Assume now that you need to make recommendations regarding the optimum sites for pediatric clinics inSan Francisco. Recommendations will derive from selecting the sites with the largest target population(s)within respective trade areas. To create a table containing this information, perform tutorial 2-18, whichfollows.

TUTORIAL 2- 18: CREATING A QUERY RESULTS TABLE

1. Select Query > SQL Query from the main menu bar.

2. Build the query as shown in the following illustration of the SQL Select dialog box. First, in the "FromTables" section, select Sites. In the where Condition type = “pediatric” . Next, in the Order by Columnssection, select potential_no. As shown in the illustration, key in a space and desc (for descending) afterpotential_no to sort by the highest number of potential target customers to the lowest.

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SQL Select dialog box showing query definition.

3. Verify that the Browse Results option is checked so that you can view the query results.

The previous query will list the sites by type and target population in descending order. As shown in thefollowing illustration, site 1 is the optimum location for a pediatric clinic.

Browser Showing site rankings by target populations.

Select an optimum site by clicking on the box adjacent to the id_no column. The site should be highlightedon the map. Site 1 will be the only one selected, as shown in the following illustration.

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Identifying Potential Geriatric Clinic Sites

Site 1 selected in the Browser window.

In order to take a closer look at site 1, zoom in to the map. Access the Layer Control dialog box to returnvisibility to the SF_STRTS layer. This will facilitate examination of the site relative to the transportationnetwork. As seen in the following illustration, site 3 is located near the San Francisco County border at theintersection of Mansell, Brazil, and Persia streets.

Map showing close-up of optimum pediatric clinic site in street network.

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Summary

At this juncture in the series of tutorials, you can offer alternative sites for pediatric clinics to county planners. Moreimportantly, you have just completed a typical GIS analysis using MapInfo Professional. If you struggled throughthe tutorials, do not worry. The rest of the book provides detailed information, tutorials, and exercises that will helpanswer many of your questions about MapInfo functions and GIS in general.

13 chapter 2 whirlwind tour: a field trip …apollo.umenfa.maine.edu/sfr400/inside mapinfo...

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