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Learn about the history and evolution of LOGO, a programming language designed for children. Explore the language concepts and basic commands, and see examples of turtle graphics in action. Discover the future of LOGO with new releases and advancements in the field.
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LOGO "Turtle Graphics“ for kids.
History • Logo: from Greek logos for “word” • Developed by a team at MIT in 1960s • Notable: Seymour Papert • Mathematician from Geneva • Worked with Piaget who influenced him • Designed as a dialect of LISP
Why the Turtle? • Originally a robotic creature sat on floor • Domed shape with shell-like electronics casing • Slow movement of device • Directed to move around and draw by typing commands at computer • Designed to be programmed by children • Less expensive version created on computer
Object Logo MacLogo Logo Learner IBM Logo Comenius Logo WIN LOGO PC LOGO LEGO LOGO LEGO LOGO Evolution • 130 existing implementations • Driven by commercial and regional factors 1977 1985 1993 1967 2003 TILOGO Apple LOGO Atari Logo LOGO Writer Logo Grafico MicroWorlds LOGO Mach Turtles Logo UCB Logo MSWLogo
Language Concepts • Basic commands • Control Structures • while condition [instruction list] • until condition [instruction list ] • repeat number [instruction list] • Recursion (preferred paradigm) • Scoping • Global variables: if not declared before use • Local variables: • may be declared • Input variables for functions are local
Basic commands • Forward 100 (FD 100) - moves the turtle forward 100 units • Back 50 (BK 50) - moves the turtle back 50 units • Right 45 (RT 45) - turns the turtle 45 degrees to the right • Left 90 (LT 90) - turns the turtle 90 degrees to the left • Home - Returns the turtle to its origin • ClearSceen (CS) - Erases the screen
Features • Graphics / Music • Extensibles: basic operations “primitives.” • Working Definitions: allows for user-defined new definitions • Modularity • Interactivity • Flexibility
Recursion • to spiral :size • if :size > 30 [stop] ; a condition stop fd :size rt 15 ; many lines of actionspiral :size *1.02 ; the tailend recursive call • end
MSW LOGO Implemenation Source: http://www.softronix.com
Example: Square • Turtle Moves forward and turns 90º 4 times • REPEAT 4 [FD 100 RT 90] Source: http://mckoss.com/logo/
Examples Source: http://www.yukoncollege.yk.ca/
Future of Logo • New Releases of LOGO: • NetLogo • Parallel modeling and simulation • Northwestern University • StarLogo • MIT