Difference between revisions of "KTurtle/C3/Special-Commands-in-KTurtle/English"

Title slide

Hello everybody.

Welcome to this tutorial on Special Commands in KTurtle.

Learning Objectives

• “learn” command and

• “random” Command

System Requirement

Ubuntu Linux OS version. 12.04.

KTurtle version. 0.8.1 beta.

Pre-requisites

If not,

for relevant tutorials, please visit our website.

http://spoken-tutorial.org

Dash home >>In the Search bar type KTurtle.

Click on the KTurtle icon.

Click on Dash home.

In the Search bar, type KTurtle.

Click on the KTurtle icon.

learn command

'learn' Command can take input and return output.

Switch to Kturtle Window

repeat 4

{

forward 10

turnleft 90

}

Let us take a look at how a new command is created.

Let's type a code in the editor to draw a square:

repeat 4 within curly brackets

{ forward 10

turnleft 90

}

here the number 10 specfies the length of the side of the square.

We will name of this set of commands to draw a square as square.

The command 'learn' is followed by the name of the command to be learnt, in this case it is a square.

learn space square $x

let's include the learn command within curly brackets {

repeat 4 {

let's repace number 10 by $x

forward $x

turnleft 90 } }

square takes one input argument, $x to set the size of the square.

Note that when you run this code, square returns no output.

The command learn is just 'learning' the other command square to be used later.

square command can now be used like a normal command in the rest of the code.

Let's type

learn square $x

{

repeat 4

{

forward $x

turnleft 90

} }

go 200,200

square 100

Turtle draws a square on the canvas.

The command square can be used any where any number of times in the program.

Turtle draws an another square with dimension 50.

Please note that this command can be used only within the scope of this program

Type “clear” command and Run to clean the canvas.

"random" command

“random” command takes input and gives output.

Syntax for the random command is “random X,Y”

where X and Y are two inputs.

X sets minimum output and Y sets maximum.

Output is a randomly chosen number between X and Y.

Let me explain the code.

and assigns it to the variable x.

{

forward $x

turnleft 10 }

$x=random 1,20

repeat 36

{

forward $x

turnleft 10

}

Pause the tutorial and type the program into your KTurtle editor.

Resume the tutorial after typing the program

Turtle draws a circle which is between 1 and 20 on the canvas.

Let us execute this code a few times,

You can see that a circle with a different size is generated each time.

Every time you exceute this code, a circle with a different radius is drawn on the canvas.

Let us now use both the learn and random commands in an example.

I will explain the code.

Highlight reset

the Red-Green-Blue combination is replaced by the values assigned to the variables R, G, and B in the previous step.

The canvas color is randomly set when this command is executed.

to which random values between 0 and 255 are assigned randomly.

pencolor $red, $green, $blue the Red-Green-Blue combination values are replaced by the variables

$red, $green and $blue to which random values were assigned in the previous step.

Here $x represents the size of the circle.

The repeat command followed by the code in curly brackets draws a circle.

The next set of commands that is the go commands followed by the circle commands draws circles with the specified sizes.

“ circle 5” draws a circle of size 5

At the co-ordinates X and Y specified in the go command.

For each circle, I have specified different positions on the canvas.

canvassize 300,300

$R= random 0,255

$G=random 0,255

$B=random 0,255

canvascolor $R,$G,$B

$red=random 0,255

$blue=random 0,255

$green=random 0,255

pencolor $red,$blue,$green

penwidth 2

learn circle $x{

repeat 36{

forward $x

turnleft 10 } }

go 85,85

circle 5

go 115,115

circle 5

go 145,145

circle 5

go 190,190

circle 5

go 220,220

circle 10

go 0,0

I will copy this code from text editor and paste it into KTurtle's editor.

Pause the tutorial and type the program into ypur KTurtle editor.

Resume the tutorial after typing the program.

You can execute this code at any of the speeds specified in the Run option.

I will run this code few times.

You can see the difference in randomly set values of pen color and canvas color.

Note the change in the color of the pen and the canvas on each execution.

You can execute the code how many ever times you want and note the change in the randomly set values.

Let's summarize

• “learn” command and

• “random” command.

Switch to KTurtle Window & Show Assignment

• Using the learn command, draw a

• pentagon

• square

• rectangle

• hexagon on the four corners of your canvas and

• circle at the centre of the canvas.

• Using the “random” command create various colors and

• Customize your geometric shapes and canvas.

Acknowledgement

http://spoken-tutorial.org/What is a Spoken Tutorial It summarises the Spoken Tutorial project

If you do not have good bandwidth, you can download and watch it

Conducts workshops using spoken tutorials

Gives certificates to those who pass an online test

For more details, please write to

contact@spoken-tutorial.org

It is supported by the National Mission on Education through ICT, MHRD, Government of India

More information on this Mission is available at this link

http://spoken-tutorial.org/NMEICT-Intro ]

The script is contributed by IT for change, Bangaluru.

This is Madhuri Ganpathi from IIT Bombay signing off. Thank you for joining.