GIS Application Development Dr. Frank Gossette Visiting 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? 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

/ 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 :-)