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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
                       Evolution

 130 existing implementations
                        1977         1985                     1993

  1967                                                                     2003

TILOGO
   Apple LOGO
    Atari Logo
   IBM Logo
    Logo Learner   LOGO             PC       WIN Comenius             Logo
   MacLogo                         LOGO     LOGO   Logo              Grafico
                   Writer
   Object Logo

                            LEGO
                                                      MicroWorlds              Mach Turtles Logo
                            LOGO                         LOGO                         UCB Logo
                                                                                      MSWLogo

 Driven by commercial and regional factors
      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 action
  spiral :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

				
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posted:4/5/2013
language:English
pages:12