netlogobasic1

Basic Logo Commands
In the NetLogo Command Center at the bottom of the window, you will see that you can switch between observer, turtles, patches & links by clicking on //**observer**//. The first commands you need to learn are either //**observer**// commands - to setup your environment or //**turtle**// commands - to move your turtles.

**Observer commands**
ca - clear all crt //number// - creates the number of turtles specified

**Turtle commands**
fd //number// - moves the turtle(s) forward the number of steps specified bk //number// - moves the turtle(s) backward the number of steps specified pd - puts the pen down, so when the turtle(s) move, they will leave a mark pu - puts the pen up rt //number// - turns the turtle(s) rt the number of degrees specified lt //number// - turns the turtle(s) lt the number of degreed specified repeat //number// [ ] - repeats the commands in the brackets the number of times specified

**Create a square**
To create a square With the command center set to observer>, type: ca crt 1

Change the command center to turtles> and then type: pd fd 10 rt 90 fd 10 rt 90 fd 10 rt 90 fd 10 rt 90

There's a more efficient way to create the square using the repeat command. Can you figure it out? Try creating multiple turtles and use the repeat command to create patterns.

Here's an example of using the repeat command: repeat 10 [fd 4 rt 34 bk 1 lt 180 fd 7 lt 66 bk 3]

If you get an error, check your **//syntax//**. Just like there are rules of language that dictate how the various parts of a sentence go together, programming languages also have rules for how a set of instructions can be put together. If you miss a bracket or forget to tell the program how many spaces to move forward, then you will receive a syntax error.

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Turtle shapes