LOGO

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LOGO

• CECS 4100
• R. Christensen

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What is LOGO?

• LOGO is a modern, procedural programming language
  based on the artificial intelligence language
  LISP.
• Although appropriate for beginners, it is a
  highly sophisticated language.

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What is LOGO?

• LOGO is a procedural language.
• LOGO is an interactive language.
• The programmer receives immediate feedback.
• LOGO has turtle graphics.
• LOGO uses lists as data objects.
• Numbers, characters, and words can be manipulated
  in LOGO.
• Lists are compound data structures.

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LOGOs Philosophy for Computer Use in the
Classroom

• Seymour Papert is the Father of LOGO.
• His theoretical background comes from the area of
  artificial intelligence and from the work of Jean
  Piaget.
• Papert believes the computer is best used in
  education as an object to think with rather
  than a dispenser of information.

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What is a MicroWorld?

• The concept of microworld is one Papert used to
  describe LOGO and LOGO-like environments.
• An environment for learning in which children are
  free to experiment, test, and revise theories,
  and invent their own activities.

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Versions of LOGO

• Original microcomputer versions were available in
  1979 for the TI 99/4 home computer and the Apple
  II computer.
• LCSI LOGO is what we are using
• Available for IBM and Apple
• Terrapin LOGO for Apple II family
• LOGOWriter (LCSI) combines LOGO and word
  processing

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Why Use LOGO?

• Provides a sound introduction to programming but
  is more than a programming language
• Encourages thinking and problem-solving skills
  applicable across the curriculum
• Debugging
• Learning from errors - immediate feedback
• Creates an ideal environment for experimenting
  and learning hypothesis-testing skills

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Research on LOGO

• May facilitate achievement gains in the area of
  mathematics
• May facilitate problem-solving ability
• Evidence indicates that LOGO can serve as a
  powerful tool in encouraging prosocial
  interaction, positive self-image, positive
  attitudes toward learning.
• In general, evidence suggests that working in
  pairs is most advantageous for LOGO

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Programming in LOGO

• The Primitives
• commands LOGO knows
• FD (forward)
• BK (backward)
• RT (right)
• LT (left)
• HOME (goes to home position)
• PU (lifts the pen)
• PD (puts the pen down)

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Programming in LOGO

• Perspective - sitting on the turtles back
• Procedures
• Teaching the turtle new tricks
• TO SQUARE
• REPEAT 4FD 50 RT 90
• END
• Procedures are called from the main program

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Programming in LOGO

• Using LOGO variables
• Allows an assigned value to a variable so the
  procedure can be used multiple times with
  different values
• TO SQUARESIDE
• REPEAT 4FD SIDE RT 90
• END
• Square is the procedure, side is the variable so
  the square procedure can be used for multiple
  sizes of squares

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Programming in LOGO

• What would happen here?
• TO SQUARE
• REPEAT 4FD 50 RT 90
• SQUARE
• END

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Programming in LOGO

• Recursion is an endless loop
• Can be stopped if a conditional statement is used
• IF SIDE 100 STOP
• TO SPIRAL SIDE
• IF SIDE100 STOP
• SQUARE SIDE
• RT 10
• SPIRAL SIDE5
• END

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Programming in LOGO

• LOGO numbers, words and lists
• LOGO knows how to add, subtract, multiply and
  divide (,-,,/)
• The command PRINT (35)/28 will output 32
• To indicate the data-type word, type a quotation
  mark in front of the string
• PRINT Happy Birthday
• Output Happy Birthday

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Programming in LOGO

• LOGO Lists
• A list is a group of words indicated by brackets
• PRINT TODAY IS TUESDAY
• Output TODAY IS TUESDAY
• Can teach the computer how to talk, how to
  create sentences and how to write poetry

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Programming in LOGO

• LOGO Music
• Command is TONE followed by 2 inputs - one is
  frequency (pitch) and the second is duration
• TONE 300 60
• Procedure for music might be
• TO SONG
• TONE 252 56
• TONE 349 56
• TONE 365 56
• END

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Programming in LOGO

• Using music in procedures and subprocedures
• TO MUSIC
• REPEAT 5 FIRST
• where first is the name of the first part of the
  song
• SECOND
• second is the name of the second part of the
  song
• THIRD
• third is the name of the third part of the song
• END