277:-based (i.e. relative direction and distance from a starting point) in comparison to coordinate-addressed systems such as bitmaps or raster graphics. As a practical matter, the use of turtle geometry instead of a more traditional model mimics the actual movement logic of the turtle robot. The turtle is traditionally and most often represented pictorially either as a triangle or a turtle icon (though it can be represented by any icon).
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The turtle moves with commands that are relative to its own position, such as "move forward 10 spaces" and "turn left 90 degrees". The pen carried by the turtle can also be controlled, by enabling it, setting its color, or setting its width. A student could understand (and predict and reason about)
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A full turtle graphics system requires control flow, procedures, and recursion: many turtle drawing programs fall short. From these building blocks one can build more complex shapes like squares, triangles, circles and other composite figures. The idea of turtle graphics, for example is useful in a
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programming language's standard library includes a Turtle graphics module. Like its Logo predecessor, the Python implementation of turtle allows programmers to control one or more turtles in a two-dimensional space. Since the standard Python syntax, control flow, and data structures can be used
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The ideas behind turtle graphics can be extended to include three-dimensional space. This is achieved by using one of several different coordinate models. A common setup is cartesian-rotational as with the original 2D turtle: an additional "up" vector
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command is used to rotate the "up" vector around the "forward" vector. The article proceeds to develop an algebraic theory to prove geometric properties from syntactic properties of the underlying turtle programs. One of the insights is that a
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The turtle has three attributes: a location, an orientation (or direction), and a pen. The pen, too, has attributes: color, width, and on/off state (also called
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alongside the turtle module, turtle has become a popular way for programmers learning Python to familiarize themselves with the basics of the language.
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is also sometimes used in graphics environments as an alternative to a strictly coordinate-addressed graphics system.
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498:"3. Hello, little turtles! — How to Think Like a Computer Scientist: Learning with Python 3"
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added support for turtle graphics to Logo in the late 1960s to support his version of the
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An animation that shows how the turtle is used to create graphics by combining
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the turtle's motion by imagining what they would do if they were the turtle.
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523:"3D turtle geometry: artwork, theory, program equivalence and symmetry"
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The
Children's Machine: Rethinking School in the Age of the Computer
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426:"Turtle Geometry in Computer Graphics and Computer Aided Design"
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474:"25.1. turtle — Turtle graphics — Python 3.7.0 documentation"
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command is really a shorthand of a turn-roll-turn sequence.
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Cheloniidae Turtle
Graphics is a 3D turtle library for
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Verhoeff 2010 implements the two vector approach; a
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Mindstorms: Children, Computers, and
Powerful Ideas
60:. Unsourced material may be challenged and removed.
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249:Turtle graphics are often associated with the
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527:International Journal of Arts and Technology
448:"Friends of the Turtle: On Logo And Turtles"
180:commands while a pen is touching the paper
156:. Turtle graphics is a key feature of the
120:Learn how and when to remove this message
424:Goldman, Ron; Schaefer, Scott; Ju, Tao.
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223:called this "body syntonic" reasoning.
200:A turtle graphic pattern drawn with a
367:Animated gif with turtle in MSWLogo (
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58:adding citations to reliable sources
311:Pattern drawn with a Python program
446:Thornburg, David D. (March 1983).
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559:Spencer Tipping on cheloniidae
154:Cartesian plane (x and y axis)
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571:Pietrocola, Giorgio (2005).
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603:(2nd ed.). New York:
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638:. New York: Basic Books.
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502:python.camden.rutgers.edu
251:Logo programming language
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158:Logo programming language
630:Papert, Seymour (1993).
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561:(retrieved 2016-9-17)
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605:Basic Books
544:28 February
339:. It has a
280:Today, the
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483:2018-08-23
411:References
152:") upon a
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458:6 October
190:iterative
597:(1993).
452:Compute!
380:L-system
359:See also
347:) and a
233:fractals
164:Overview
400:MSWLogo
395:FMSLogo
390:NetLogo
385:UCBLogo
376:KTurtle
369:Cycloid
245:History
174:forward
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282:Python
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148:(the "
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101:JSTOR
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460:2013
353:dive
345:roll
341:bank
337:Java
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211:and
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