Chandrika: Created page with '[http://spoken-tutorial.org/wiki/index.php/File:Resources-for-grammer-of-turtle-II.zip Resources for "Grammar of TurtleScript - Part II"] '''Title of script''': Grammar of Turt…'

2012-11-27T12:01:58Z

Created page with '[http://spoken-tutorial.org/wiki/index.php/File:Resources-for-grammer-of-turtle-II.zip Resources for "Grammar of TurtleScript - Part II"] '''Title of script''': Grammar of Turt…'

New page

[http://spoken-tutorial.org/wiki/index.php/File:Resources-for-grammer-of-turtle-II.zip Resources for "Grammar of TurtleScript - Part II"]

'''Title of script''': Grammar of Turtle Script-Part II

'''Author: Sindhu'''

'''Keywords: '''

{| style="border-spacing:0;"
| style="border-top:0.002cm solid #000000;border-bottom:0.002cm solid #000000;border-left:0.002cm solid #000000;border-right:none;padding:0.097cm;"| <center>'''Visual Cue'''</center>
| style="border:0.002cm solid #000000;padding:0.097cm;"| <center>'''Narration'''</center>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Hi everyone,

Welcome to the tutorial on Grammar of Turtle Script-Part II.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 2
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| If this is the first time you are using KTurtle,

please view the tutorial Introduction to Kturtle, which will help you understand the installation and interface of the application, and also some of the basic commands to move the turtle.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Also view the tutorial Grammar of Turtle Script-Part I,

to understand few more commands used in the Kturtle environment.

These tutorials can be viewed on the spoken tutorial website ([http://www.spoken-tutorials.org/ www.spoken-tutorials.org]).

This tutorial will introduce some more commands to be used in the KTurtle environment.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| We will learn the

* '''learn '''command
* '''random '''command

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| For this demonstration, I am using the Linux Operating System Ubuntu v11.04, and Kturtle v0.8.1 beta.

Let us first look at the '''learn '''command.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 6

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| ''''learn' Command'''

'''learn''' is special as it is used to create your own commands.

The commands you create can take input and return output.

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

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Kturtle Window

type the following code:

'''repeat 4'''

'''{'''

'''forward 10'''

'''turnleft 90'''

'''}'''

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I will launch the Kturtle application

Let us enter the following lines of code in the editor to draw a square:

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

Now let us learn the commands involved to draw a square using the '''learn '''command.

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 '''square.'''

So i will enter the command '''learn '''before the command '''square'''

'''learn square $x'''

'''{'''

'''repeat 4'''

'''{'''

'''forward $x'''

'''turnleft 90'''

'''}'''

'''}'''

So the new command that we have defined here is called '''square'''.

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

One important point to be noted here is,

when you run this piece of code,

'''square''' returns no output.

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

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

Let me add few more lines of code here.

Type the following code in your editor:

'''learn square $x'''

'''{'''

'''repeat 4'''

'''{'''

'''forward $x'''

'''turnleft 90'''

'''}'''

'''}'''

'''go 200,200'''

'''square 100'''

Let me select '''Run '''from the toolbar to run this piece of code from the editor.

The turtle now draws the square on the canvas.

The command '''square '''can now be used anywhere and any number of times in your program now.

Note that this command can be used only within the scope of this program.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Slide 5
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| ''''random' Command'''

'''random '''is a command that takes input and gives output.

The syntax for this command is '''random X,Y'''

where '''X '''and '''Y '''are the two inputs.

'''X '''sets the minimum output and '''Y '''sets the maximum.

The output is a randomly chosen number between X and Y.

Let us pu the '''random '''command to use in the application.

In my editor, I will enter a few lines of code to draw a circle.

'''reset'''

'''$x=random 1,20'''

'''repeat 36'''

'''{'''

'''forward $x'''

'''turnleft 10'''

'''}'''

Here, the command '''random 1,20 '''selects a random number which is equal or greater than '''1 '''and equal or lesser than '''20,'''

and assigns it to the variable '''x.'''

When you run this piece of code, a circle with a radius of size, which is in between '''1 '''and '''20 '''is drawn on the canvas.

Let us execute this code a few times, and 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.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us now use both the '''learn '''and '''random '''commands in an example.

Here, i have with me few line of code that demonstrates the use of both the '''learn '''and the '''random '''command.

i am going to copy the entire code onto my clipboard and paste it in my editor in the Kturtle application.

'''reset'''

'''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'''

Let us see what each line means here.

'canvassize 300,300' sets the width and height of the canvas to 300 pixels each.

'''$R''', '''$G''', and '''$B '''are three variables to which I am assigning random values between 0 and 255.

In the command 'canvascolor $R,$G,$B' ,

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 set randomly when this command is executed.

'''$red, $blue, $green '''are another set of variables

to which values between 0 and 255 are assigned randomly.

Again in the command ''''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.

The color of the pen is also set randomly when the command is executed.

'penwidth 2' sets the width of the pen to 2 pixels.

I have next entered the code to '''learn''' to draw a circle.

Here '''$x '''represents the size of the circle.

The next set of commands i.e the '''go '''commands

followed by the '''circle '''commands draws circles with the specified sizes.

The command '''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.

Lets execute this code now.

I am running this execution at full speed.

But you can execute your code at any of the speeds specified in the '''Run '''option.

I will run this code few more times, so that you can see the difference in the randomly set values of pen color and canvas color.

When I execute the code one more time, note the change in the color of the pen and the canvas.

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

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Slide 6

Switch to KTurtle Window & Show Assignment
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| '''Assignment'''

As an assignment for you to solve,

using the '''learn '''command,

draw a pentagon, a square, a rectangle, a hexagon on the four corners of your canvas

and a circle at the centre of the canvas.

Using the '''random '''command create various colors and customize your geometric shapes and the canvas.

I have created my own customized canvas for the geometric shapes,

and your assignment should look similar to this.

Let me run the piece of code in the application.

You can see the geometric shapes and the color of the canvas changing each time.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Slide 7
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I would like to acknowledge the spoken tutorial project

which is part of the talk to a teacher project.

Supported by the National Mission on Education through ICT, MHRD Government of India.

And you can see more information on this on the Spoken Tutorial Website.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Slide 8
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Thank You.

This is Sindhu signing off. Enjoy playing with KTurtle!

|}

KTurtle/C3/Grammar-of-TurtleScript-Part-II/English - Revision history

Chandrika: Created page with '[http://spoken-tutorial.org/wiki/index.php/File:Resources-for-grammer-of-turtle-II.zip Resources for "Grammar of TurtleScript - Part II"] '''Title of script''': Grammar of Turt…'