Graphs, grouping, pie charts and other ‘ stuff ’ .

1. Graphs, grouping, pie charts and other ‘stuff’. Peter Fox GIS for Science ERTH 4750 (98271) Week 10, Tuesday, April 3, 2012

2. Contents (eek!) • Dispersing points • Creating points for intersections of lines • Extracting latitude and longitude from a geocoded table • Selecting data that are not geocoded • Web links • Adding tools • Pie charts on thematic map • Graphs • Editing attributes in tables • Manipulating objects within MapInfo • Graduated symbol maps • Bivariate thematic maps

4. Pie charts (sorry, but they survive)! • Pie chart of the ethnicity of the population for the New England States (table usa). • Open USA.TAB, select New England States with marquis select, save as new table (ne_states.tab). • Display NE states only, Create Thematic map, select Pie Charts > Next > Table = NE_states, select and Add from fields, pop_cauc, pop_black, pop_native, etc. > Next. • Click Styles > turn on Half Pies > OK > OK.

5. Looks like this …

6. More thematic maps • Bar charts to show the quarterly rainfall for the New England States. • Open ne_states and US_rain. • Select rain data points from NE states and write to separate table NE_rain. • NE_rain has monthly data so we need to put it into quarterly sums. • To do this add 4 columns to the table (Table > Maintenance > Table structure) and Update columns to hold quarterly sums.

7. More thematic maps • Create Thematic map, select Bar Chart > Next > select columns to plot > Next > OK. • But … because some states have multiple measurement sites we have to group them. • Query > SQL select > Columns = State,sum(q1),sum(q2),sum(q3),sum(q4) > Tables = NE_rain > Group by = state > into Table = ne_q. • Create Thematic map, select Bar Chart > Next > select columns to plot > Next > OK.

8. Looks like this

9. Adding/ comparing • Using a table of friends zipcodes (earlier exercise), add their ages and add 5 new friends (or class members) to the table. • Plot them on a map that distinguishes new friends from old and their ages. • Open friends table (NB save copy as new_friends). • Open new_friends, Table > Maintenance > Structure > Add field old_new as character (3) and age as Integer. • Open the table in Browser window and add new information. You can also edit the data via the Info tool.

10. and • To add or delete rows, go to Edit > New Row or Edit > Clear. • You’ll have to Geocode the data again. • To remove rows from the table Table > Maintenance > Pack Table > Save changes > read table in again.

11. Creating attributes • Make CL editable > put objects on map with tools > Map > Save CL objects and name the new table • Open new Browser window • Table > Maintenance > Table structure > add fields (add "area" column) • Table > Update column > Column = "area" > Value > Assist > Function > Area • Save table

12. Modify graphic objects • Make layer with objects editable (if you can’t do this, try saving table with a different name). • Select the object to be changed. Select Reshape icon or Edit > Reshape. • Click on the node to be moved. • Select multiple nodes in sequence with Shift-click (short-route) or Ctrl-click (long-route) and move them together. • Ctrl-click on same node twice will select all nodes.

13. Modify graphic objects • If the object borders another and shares nodes, first go to Options > Preferences > Map window > click on Move duplicate nodes in the same layer. • If you don’t do this, you can open up gaps between objects or make them overlap. • Use add nodes icon to add nodes.

14. Combining objects • Make table editable, Select objects to be combined, Objects > Combine, select how to combine object attributes.

15. Splitting objects • Objects must be split with another object which can either exist or be made on the cosmetic layer. • First, make splitting object if necessary. • Make CL editable, create polygon to be the "splitter", save to cut.tab (Map > Save Cosmetic objects). • Make target file editable, select the object to be split then Object > Set target, select the "splitter" object, then Objects > Split > OK. • Remove cut.tab from display.

16. Graduated symbol maps. • Graduated symbol maps use symbol sizes to represent different values. • To make a graduated map of Japanese earthquakes where the earthquake magnitude is represented by symbol size: read tables ‘world’ and ‘japan_quakes’ > Map > Create TM > Graduated > Next > choose table = japan_quakes and field = mb > Next > Modify settings > OK.

17. Bivariate thematic maps • Bivariate maps are those that represent two attributes with a single symbol on the map. For example, we can represent earthquake depth with color and earthquake magnitude with symbol size. • To do this first create a TM of the earthquake depth using point ranges. Use 6 ranges and select equal count. • Then create a second TM using point ranges for the mb field.

18. Bivariate thematic maps • Under step 3 of 3 click Styles > Options and under Autospread select Size. • Then under Apply choose size again. • The symbols should become hollow but of graduated size. • Click OK and the graduated size symbols draw over the color ranged symbols. • Deep Japan earthquakes.

19. Voila, and uh-oh…

20. Mapbasic - prelude • MapBasic is a programming language for MapInfo that encompasses many direct calls to mapping and database functions. • It is used in one of two ways: either through Options > Show MapBasic window in MapInfo or through the MapBasic interface and compiler. • MapBasic Window

21. Mapbasic compiler • MapBasic is a standalone program to develop programs that interface with MapInfo. • One can manipulate data and maps from within MapBasic programs. • E.g. a MapBasic program that performs the same function as that given above for the MapBasic Window looks like this: declare sub main sub main open table "c:\mapinfo\data\world.tab" Interactive [replace with correct path] map from world select * from world where pop_1994> 10000000 into selection browse * from selection map from selection end sub

22. The body of the program is identical to the MapBasic Window commands. • To run this program, start MapBasic, select File > New, paste the program into the editor window, select Project > Compile current file (or Ctrl-K), then select Project > Run (or Ctrl-U). • If MapInfo is not already running it will start and perform the tasks. • The result should be a map window showing only countries with > 10 million inhabitants.

23. Mapbasic - prelude • One can perform many of the MapInfo functions via the MapBasic window by entering command lines. • For example to open the world table and make a map of countries with greater than 10 million people, type in the MapBasic window: open table "c:\mapinfo\data\world.tab" Interactive map from world select * from world where pop_1994> 10000000 into selection browse * from selection map from selection • There are several functions available for MapBasic. • To view MapBasic functions, open the MapBasic window as you perform tasks with MapInfo's interactive screen.

24. Dispersing points • Sometimes when we geocode we get many points falling at the same coordinates. • This happens because the data are geocoded to the centroid of the entity, for example when we geocoded with zip codes. • For the purposes of the map, we can disperse the points to give the proper representation of the number of points. • To do this we can use the MapBasic window. Choose Options> Show MapBasic window to open the MapBasic window.

25. Dispersing points (ctd) • Within the window type: randomize update selection set obj = createpoint(centroidx(obj) +.02*rnd(1), centroidy(obj)+.02*rnd(1)) • This will randomly redistribute the points to the northeast within 0.02 degrees (or whatever the distance units are). • To randomly redistribute them about the current point, use: update selection set obj = createpoint(centroidx(obj) +.02*(rnd(1)-.5), centroidy(obj)+.02*(rnd(1)-.5)) • The table will be automatically updated and the new points will appear on the map. Make sure you save a copy of your original data.

26. Creating points for intersections of lines • In some cases we might be interested only in the intersections of lines, for example street intersections. We can create a new table of points containing only the intersections. • Open the street file nyrensd. Make 2 copies of the nyrensd file and give each a unique name (File > Save copy as) such as str1 and str2. Open the 2 new files you have created. • Choose Query > SQL select. In the dialog box enter: • Select columns = str1.streetname + "&&" + str2.streetname

27. Then From Tables = str1, str2 Where Condition = str1.obj Intersects str2.obj and str1.streetname <> str2.streetname Into Table Named = Intersection • Save the Intersection table (File > save copy as).

28. Lon/lat from geocoded table • You may want to see the latitude and longitude in your geocoded table. • There are 2 ways to do this depending on whether you want a new table or want to put the lat/lon in your original table. • To create a new table use Query > SQL select. • Under select columns, enter columns you want in the new table and then also put: • CentroidX(obj) "Longitude", CentroidY(obj) "Latitude"

29. And • To add the lat/lon to an existing table, select Table > Maintenance > Table structure and add 2 new columns to your table. • Call the Lat and Lon and make them ‘float’ types. • Then choose Table > Update column. Enter your table name under Table to update and Get value from Table. • Column to update should be your lat or lon and Value shoud be CentroidY(obj) for latitude and CentroidX(obj) for longitude.

30. Selecting data that are not geocoded • You may want to get a Browser list of points that did not geocode from a particular table. • Open the table and choose Query > Select. Under that Satisfy enter not obj. • This selects all the data records that are not objects, i.e., not geocoded. • Example: Geocode friends.xls with zip_codes and find those that do not geocode.

31. Un-geocoding tables or data • Un-geocoding means removing the objects from a Table. • You may want to do this if you are going to re-geocode using a better method or have better data to geocode with. • To un-geocode an entire table: select Table > Maintenance > Table structure. • Clear the Table is Mappable check box > OK > OK. • This is irreversible.

32. Un-geocoding tables or data • To un-geocode selected objects: Plot the data in a map window. • Select the points you want to un-geocode. • Choose Layer control and set the layer to be editable. • Choose Edit > Clear Map objects only. • This un-geocodes the data but does not remove them from the table. • To undo choose Edit > Undo Deletion.

33. Creating web links for maps • WWW links can be incorporated into the maps using the HotLink button (the lightning bolt). • To create the links, add a column to your table through the Table > Maintenance > Structure option. • Make it a character string long enough to accommodate your longest URL. • Open the table in the Browser window and type in the URLs. • In Layer Control, click on the HotLink button.

34. Creating web links for maps • Select the column containing the links in the FilenameExpression dropdown box and check the Save options to table metadata box to save URLs with table. • Don't forget File > Save table. • To activate the link on the map, click on the HotLink button (the lightning bolt) and then on the map object. • Example: Add http://www.states.AL.us to the states table for Alabama.

35. Adding tools to MapInfo • Tools are external routines that can be called from the MapInfo interface. • They are accessed via the Tools menu. • A tool can be developed as a MapBasic program and its compiled form (.mbx file) is run from MapInfo. • To add a tool, select Tools > Tool Manager > Add Tool and fill out the location of the tool (the .mbx file) and a description. • The tool will run. • To run it later, select Tools, then find the tool and check Loaded. • Checking Autoload will cause it to run on Startup of MapInfo. • Example: Add the Xcel_2_tab tool.

36. Summary • Topics for GIS (for Science) • Extras! • For learning purposes remember: • Demonstrate proficiency in using geospatial applications and tools (commercial and open-source). • Present verbally relational analysis and interpretation of a variety of spatial data on maps. • Demonstrate skill in applying database concepts to build and manipulate a spatial database, SQL, spatial queries, and integration of graphic and tabular data. • Demonstrate intermediate knowledge of geospatial analysis methods and their applications.

37. Reading for this week • MapInfo (10.8) User Guide • Chapter 5 Graphing your data • Chapter 7 Graphing and editing objects • Chapter 9 Pie charts, graduated symbols, etc. • Review the mini-exercises in these slides and work through them in MapInfo – if you have questions, ask on Friday

38. Next classes • Friday, April 6, Lab: … • Tuesday, April 10, Editing attributes, manipulating objects in MapInfo • Friday, April 13, Lab: geostatistics and some more maps • No class April 17 (Grand Marshall week)