GIS Software

Dr. M. Gavrilova

What is a GIS system?A system containing spatially referenced data that can A system containing spatially referenced data that can

be analyzed and converted to new information for a be analyzed and converted to new information for a specific purpose.specific purpose.

GIS software: ArcInfo GeoSQL SmallWorldStatistical analysis software: S-Plus Extension for ArcView GIS 3.2 SpaceStat (TerraSeer) Grass GISGIS visualization software: ArcView, ArcGIS, Visual_Data, GIS Viewer, etc.

Oracle Spatial

PostgresSQL

SDE

Traditional Relational Database

Spatial Processing

What is the difference? …

Representation

Database Query Table

GIS Query

Designed by ESRL in 1969 Features:

◦ Querying relational databases◦ Tool for statistical analysis◦ Specific display tools (scale change or zooming)◦ Support for graphical formats

Data collection Data representation Data storage Data analysis and computation Concurrency and recovery Query facility and optimization

Graphical display and interaction with the user (ArcEdit)

Map editing tools (ArcPlot) Network management (optimal paths)

(Network) Layers overlaying (Overlay) Underlying data structure (ArcScan)

Surface is represented as TIN or GRID Grid has a reference to a Value Attribute

Table TIN: List of Triangles, List of Associated

Nodes, List of Neighboring Triangles

Objects in ArcInfo:◦ Point◦ Arc◦ Polygon

More complex objects: graphs, sequence of arcs. Can be described in a specific language.

For instance, a route can be defined within a graph or a network, having specific attributes, a set of roads, a city block can also be represented.

Map queries: after a Map is created, a different coverage (highways, regions, elevation, etc…)

2 modules:◦ ArcView Spatial Analyst◦ ArcView Network Analyst

Requests to the DB are written in a query-type language.

Designed by ESRI Desktop GIS Oriented toward data integration Used for analyzing maps – 2D

◦ Back End CapabilityLink to relational (SQL) databases or filesData modelingBase MappingSecurity and Integrity

◦ Front End CapabilityInteractive, visual analytical performanceManipulation of data setsPresentation and output

Relational Database (SQL) Querying

Libraries,Images

Embedded, Linked, SQL Dictionaries

Data Formats

Raster and Vector Support

Format Handlers (loadable drivers)

Fixing Errors in Digitized Data

Storage Structures◦ Spatial Objects (Points, Lines, Polygons)

Storage Structures◦ Non spatial properties

◦ Derived Objects and Geo-Coding

Line Geo-CodingLabels & Attributes

Spatial Analysis◦ Buffering

◦ Generalization

Polygon DissolveLine Generalization

Overlay Polygon

Dissolve

Data Themes1. Definition2. Data Source3. Geographic Search Criterion4. Query Condition5. Graphical Style6. Labels7. Column List8. Data

Page Layout and Printing

Licensed by GE Power Systems Smaller GIS – business solution OO development language (Magik) Raster/vector graphics Has intranet/internet network capability High-level query language

Oracle Postgre SQL SDE

Index-aware operations:◦ Contains, covers, inside, overlaps, touch, disjoint

Other:◦ Union, difference, intersection, area, length

Spatial Attribute Types:◦ point, line string or polygon

Spatial Operations, Spatial Indexing

Open source Operations:

◦ Triangulate, scale, polymorphic (works on different types of geometric objects)

No topological operations (adjacency is not implemented)

No overlay operation

GIS CADCustom

application3D visualization

SDE server

Data files

ArcInfo files

DBMS (spatial,CAD, graphics)

There are a number of Software that is being used for statistical analysis of spatial data.

S-Plus Extension for ArcView GIS 3.2

SpaceStat (TerraSeer)

Grass GIS

Typical GIS software does not perform the following functions satisfactory:◦ Robustness◦ Reliability◦ Completeness◦ Capability and features◦ Specific Spatial techniques for Autocorrelation

and analysis◦ Spatial hypothesis testing

Basic Statistics  Summary statistics Crosstabulations Hypothesis tests• Probabilities, quantiles, and

densities Random number generation Bootstrap and jackknife estimation Power and Sample SizeRegression Basic linear regression Polynomial regression Robust regression Constrained regression Logistic regression Generalized linear models Robust MM Regression Linear regression with correlated

errors

Nonlinear regression and minimization Nonlinear regression with correlated

errors Minimum-sum optimization for maximum

likelihood and generic optimization Constrained nonlinear regression Nonlinear mixed effects Among Other functions Mixed Effect Models Classifications Nonparametric regressions Smoothing and interpolation Multivariate analysis Cluster Analysis Quality Control

Graphical feature of the software Time series charts: high-low-open-

close and candlestick Combined vertical/horizontal error bar

charts Multiple x-y pair plots Nonlinear curve fitting plots 2-D plots: area plots, barplots,

boxplots, density plots, dot charts, histograms, pie charts, and more

Scatterplot extensions: scatterplot matrices, linear fits, smooth fits, vary symbol color and size, text as points

3-D plots: point clouds, surface plots, contour plots, color image plots, 3-D barplots

Time series plots Quality control charts Statistical model summaries and

diagnostics

Advanced Data Visualization  Easy control of axis scales Pop-up descriptions for data values 2-D and 3-D graph palettes for easy

plotting Multiple simultaneous 3-D rotation views 2-D projections in 3-D space Multiple graphs per page with auto-

formatting Interactive 3-D view angle specification Interactive observation identification Multiple, user-defined color maps

With the S+SpatialStats module: Spatial autocorrelation a to assess global

association for the values of a variable as a consequence of their location

Build neighbor weight matrices based on adjacency as well as distance between sampling units

Local spatial association can highlight clusters of data spatially correlated

Supports Moran's I index and Geary's c measures of correlation

Spatial regression to depict relationships between variables for each spatial unit, given a neighbor weight matrix

Model variables may be selected from ArcView themes or S-PLUS data sets

SpaceStat: http://www.terraseer.com/Spacestat.html

Despite solid indications that spatial effects matter, much empirical work that uses spatial data still fails to take its distinctive characteristics into account. Until SpaceStat, there was no comprehensive software package that covered a reasonable range of techniques in spatial statistics and spatial econometrics.

SpaceStat provides tools for the creation of spatial weights matrices, exploratory spatial data analysis and spatial econometric analyses

SpaceStat was first released in 1991, and since then was updated 4 times. In 2002, SpaceStat joined forces with TerraSeer.

ClusterSeer 2 evaluates disease clusters and non-disease events such as crime or sales data. You can determine whether a cluster is significant, where it is located, and when it arose, providing insight into the origin, causes, and correlates of the event.

BoundarySeer is the premier product for the detection, description and analysis of geographic boundaries. It detects patterns in your data and then tests them statistically. Aside from edge detection, most GIS do not provide any boundary analysis techniques.

GrassGIS: http://grass.itc.it/statsgrass/

This is an open source, language-based software, which allows in-house development of spatial tools that can be used to manipulate data that must be represented by unconventional statistical systems.

All of its functionality is essentially a subset of S-plus.

Rich variety of software appeared in the last 10 years to deal with spatial data, statistical analysis, and database queries on complex geometric objects.

Future directions include web-based, server-based distributed database with hierarchical data representation and advanced visualization capabilities