GIS Application Development

Dr. Frank GossetteVisiting Professor of Geography/GIS

California State University, Long Beach

What are Applications?

• Very Specific, Limited Task

• Simple (sometimes crude) User Interface

• Do something the General Purpose Software doesn’t do

• Do something that you need to have done

• Extend your toolbox with new functions

• Give you control of inputs and outcomes

Examples of Applications?

• Calculate a Statistic not in the GIS

• Reformat a Table for use as Attribute Data

• Combine Categories or Recode Attributes

• Give Co-Workers GIS Functionality

• Integrate Data from Other Applications

• Make a Map available over the Internet

What is Development?

• Writing a “Macro”

• Adding a Button or Menu to your GIS

• Combining Commonly-Used Functions

• Automating Operations

• Programming an Algorithm into the GIS

• Programming a Stand-Alone Module

What is a Program?• “High-Level Instructions” written in a specific

“Language”

• Statements which conform to a specific syntax and set of rules

• Algorithms: Detailed, Unambiguous Steps

• Interpreted or Compiled Machine Codes

• Data Input and Output Results (I/O)

• A User-Interface

Components of a Program

• Specify Data Used (Declarations)

• Initialize Constants and Variables

• Control the Flow of Events

• Specify the Algorithm and Process

• Transfer the results to the recipient

• Document the Procedure for Evaluation

Past and Future GIS Programming Languages

• FORTRAN

• MS-BASIC

• Pascal

• AML

• Avenue

• C/C++/Java

• Visual BASIC

• Python

Our Goals

• Understand the need for extending commercial GIS with user-written “applications”

• Appreciate the requirements and context of Application Development

• Gain experience in building simple programs which enhance our GIS

Our Goals, continued

• Understand the Fundamentals of Applications Programming

• Learn the rudiments of a Programming Language

• Produce a useful Application by the end of the Semester

Structure of the Course

• “Lectures” on Mondays– Discussion of Theme Topics– On-line Reading Assignments– Intro to the Week’s Programming Exercise

• “Lab” on Wednesdays– Weekly Hands-On Mapping Assignment– Instructor Guided-Group Exercise– OR Self-Guided Problem Solving– Guaranteed HELP Time

Course Requirements

• Attend All Lectures– Read All Reading Assignments (before Class!)– Notify Instructor if you must be Absent

• Get “notes and instructions” from a classmate

• Complete All Lab Assignments– Suggested Completion Dates will be Posted– One-Week FlexTime– Electronic Posting of Exercise Results

• Blackboard? E-mail Attachment?

Course Requirements, Cont.

• Complete a Final Semester Project– Topic to be Determined in Consultation– Specific GIS Application Problem– Previous Literature and Prior Examples– Your Solution and its Rationale

• In-Class Presentation of Results– 15 min to share results

http://www.csulb.edu/~gossette/salzburg/

• Blackboard Alternative and Backup

• Reading and Lab Assignments– Reading URLs– Data and Tutorial Info

• Check Frequently– News & Updates– Last-Minute Schedule Changes– Mistakes and Fixes :-)