Where2.0Now - Finding the heat in Thematic Maps

Where2.0Now - Finding the heat in Thematic MapsJohn FaganProgram Manager, Microsoft

1990’s – Sean Phelan’s vision

1996 - Multimap.com launched (no maps)

Desktop GIS - MapInfo Desktop for Power Mac v4

1997 - Multimap GeoStack

MapInfo Desktop for power mac

Hacked to make it serve maps over http

MapInfo Desktop for power mac

Hacked to make it serve maps over http

Collins Bartholomew

Raster maps

Collins Bartholomew

Raster maps

Multimap.comMultimap.com

gif.cgiMapping API +Caching

engine

gif.cgiMapping API +Caching

engine

MySQLMySQL

Bartholomew & OS

Gazetteer

Bartholomew & OS

Gazetteer

places.cgiplaces.cgi

cache miss

MapInfo for Power Mac v4 Features

• Local & Remote Data Access – Directly read dBase, Lotus 1-2-3, Microsoft Excel, delimited ASCII in native formats

• Geocoding – Create points – Geocode to street address, ZIPcodes, census tract, user-definedmatch options

• Map Creation and Editing – Raster map registration and display .GIF, .JPEG, .TIFF, .PCX, .BMP, .TGA, .BIL – Graphics Import – DXF – Digitizing to create vector images; supports digitizers – Autoscrolling to create or edit objects larger than the current window – Autotracing of existing object with mouse or digitizer – Clone Mapping to copy current map window – Customize map objects (fill patterns, line types, symbols, True Type fonts) – Map Editing Functions: Reshape objects, snap to editing, move objects, select multiple nodes for deletion, overlay nodes, copy objects, create polylines from

regions, create regions from polylines, smooth / unsmooth, revert table, clear map objects only • Data Visualization

– Create thematic maps using ranged shading, bar charts, pie charts, dot densities, graduated symbol and individual values – Range classification of maps based on equal count, equal ranges, inflection point, natural breaks, standard deviation, quantile, user defined – Combine thematic options to create maps that display multiple variables from many tables – Thematic joins based on: Count, sum, value, average, min/max, weighted average, proportional sum, proportional average, proportional weighted average – Attach data to any object – Multiple views Dynamically linked "hot" views of map, row & column, graph Page layout view District management browser/window display Legend window – Summary statistics window MapBasic command window Set layer display zoom – Zoom range 55 ft. to 100,000 miles Set layer display order View hundreds of layers Seamless map layers – Escape from map redraw – 18 projections available On the fly transformation/display Overlay different projections Convert between projections

• Analysis Capabilities – Get information about any object – Donut/island polygons supported – Polygon Overlay Operations Data aggregation / disaggregation, erase, erase outside, split, combine, overlay nodes – Buffers: Create buffers around any object or group of objects--points, lines, polylines, polygons – Geographic Selection

• Find any object • Points within radius/polygon

Lines/polylines within radius/polygonPolygons within radius/polygon

– SQL/Advanced Querying Language Query based on expressions, perform aggregations, display derived fields, perform subqueries, do multi-table joins and perform geographic joins

– Relational query operators • Standard and Geographic operators • Contain, contains entirely, within, entirely within, intersection/union

MapInfo for Power Mac v4 Features

• Functions – Day, month, year, current date or weekday functions. – Change strings to upper, lower or proper case. – Find sin, cos, arcsin, arccos, sum, average, min, max, absolute value, exponential or rounded. · Find area, perimeter, length,

and determine x/y centroid. – String functions – Conversion functions. Results can be treated as a separate table and saved as a separate database. – Aggregate functions from SQL queries – Group or sort data based on any field or expression. Sum, min, max, average, weighted average or count.

• Statistics – Show count, total, mean, standard deviation, variance, range, min and max of a group of values. – Dynamically display sum and average of a selection.

• Database Management – Create and change width or type of field, add/delete fields, index any field. Field types supported: character, floating point,

integer, decimal, logical, date. Number of records limited only by hard disk storage; up to 250 fields per record. • Display and Presentation

– Map Clipping to highlight region – Automatic or manual labeling – Label position by anchor point, offset distance, callouts – Text styles: bold, italic, underline, all caps, halo, boxed, shadow, double wide – True type fonts and text rotation – Hundreds of symbols and user created bitmaps – Unlimited number of colors – Scalable labels when zooming

• Output – Print individual windows or layout – Printers/plotters: Supports any Windows compatible printer or plotter. Requires Windows-compatible driver included with

Windows or from third-party vendor. – Output to Bitmap (.BMP) or Windows Metafile (.WMF)

Why should maps be for GIS Professionals only?

gif.cgi?pc=ec4a2dy

gif.cgi?pclist= ec4a2dy,ec1n2ns

gif.cgi?pclist= ec4a2dy,ec1n2ns&width=500&height=500

gif.cgi?pclist= ec4a2dy,ec1n2ns&width=500&height=500&ds=1

Multimap.com vs MapInfo

gif.cgisimple, but scalable and accessible to all

Many customers still use gif.cgi today

>> Fast forward a few years

Visualisation – Heat Maps

Value interpolation Frequency based

http://idvux.spaces.live.com/blog/cns!2EB6AAF6C3AC1EBE!1932.entry

Heat is interpolated because it is a continuous data type. If it is 100 degrees at one station and 50 degrees at a neighboring station, it must be 75 degrees somewhere between the two.

Heat brightness on the surface illustrates the frequency of crime reports

Choropleth map

Thematic Mapping API’s

Again, the web developers have come to the rescue and made GIS functionality accessible to all

http://www.programmableweb.com/tag/thematic

Wait.... Do we want web developers to carry out spatial analysis?

....it could go wrong

• Current API’s not fit for serious choropleth thematic analysis

• Will result in committing wrong resources to the wrong problems in the wrong places

• Need to understand underlying methods and limitations thereof

• Need access to underlying data

Stan Openshaw and MAUP

The modifiable areal unit problem (MAUP) is a source of statistical bias that can radically affect the results of statistical hypothesis tests.

MAUP occurs when point-based measures of spatial phenomena (e.g., population density) are aggregated into districts, the resulting summary values (e.g., totals, rates, proportions) are influenced by the choice of district boundaries.

The issue was discovered in 1934. The term MAUP was first coined and described in detail by Openshaw (1984), who lamented that "the areal units (zonal objects) used in many geographical studies are arbitrary, modifiable, and subject to the whims and fancies of whoever is doing, or did, the aggregating." (Openshaw, 1984, p.3).

The problem is especially crucial when the aggregate data are used for cluster analysis for spatial epidemiology, spatial statistics or choropleth mapping, in which misinterpretations can easily be made without realizing it.

http://en.wikipedia.org/wiki/Modifiable_areal_unit_problem

What if John Snow used todays API’s?

http://www.programmableweb.com/tag/thematic

One solution to Stan’s MAUP

• Define your own areas by aggregating existing areas1. Grab some admin areas that are small

and uniform (with respect to attributes)2. Enumeration Districts could work in UK

Haining (1990)

Aggregate areal units

• Classify areal units based on cluster analysis using a large number of common variables related to the analysis you are carrying out

• Deprivation indexes are often used for Epidemiology analysis

UK Deprivation indexes and associated variables

GIS could get this right in 1996

Bing Maps/SQL Server 2008

Aggregate areal units using STUnion()DECLARE @geom1 geometryDECLARE @geom2 geometry

SELECT @geom1 = (SELECT GeomCol1 FROM FeatureTest WHERE blah)SELECT @geom2 = (SELECT GeomCol1 FROM FeatureTest WHERE blah)

SELECT @geom1.STUnion(@geom2)

Union (here: Multipolygon)

View Choropleth overlays using Silverlight

Thematic Maps as Vector Data

Thanks

john faganubergeo.com@johnbfagan