KTurtle/C3/Special-Commands-in-KTurtle/English-timed

Time	Narration
00:01	Hello everybody. Welcome to this tutorial on Special Commands in KTurtle.
00:08	In this tutorial, we will learn about: “learn” command and “random” command.
00:15	To record this tutorial, I am using: Ubuntu Linux OS version 12.04 KTurtle version 0.8.1 beta.
00:28	We assume that you have basic working knowledge of 'KTurtle'.
00:33	If not, for relevant tutorials, please visit our website: http://spoken-tutorial.org
00:39	Let's open a new KTurtle Application.
00:42	Click on Dash home.
00:44	In the Search bar, type: "kturtle".
00:47	Click on the KTurtle icon.
00:50	Let's first look at learn command.
00:53	learn is a special command as it is used to create your own commands.
01:01	learn command takes input and returns output.
01:05	Let's take a look at how a new command is created.
01:10	Let me zoom the program text to have a clear view.
01:14	Let's type a code in the editor to draw a square:
01:19	repeat 4 within curly brackets { forward 10 turnleft 90 }
01:31	Here, the number 10 specifies the length of the side of the square.
01:37	Now, let's learn the commands involved to draw a square, using the learn command.
01:45	We will name this set of commands, to draw a square, as square.
01:50	The command 'learn' is followed by the name of the command to be learnt. In this case, it is "square".
01:59	Let us type the following code:
02:02	learn space square space $x.
02:10	Let's include curly brackets.
02:13	Let's replace 10 by $x.
02:19	New command that we have defined is called square.
02:23	square takes one input argument, $x, to set the size of the square.
02:31	Note that when you run this code, square returns no output.
02:37	The command learn is just 'learning' other command square, to be used later.
02:43	square command can now be used like a normal command in the rest of the code.
02:51	Let me add few more lines here.
02:54	Let's type: go 200,200 square 100
03:04	Using the command square 100, Turtle draws a square of dimension 100.
03:11	Let's Run the code now.
03:13	Turtle draws a square on the canvas.
03:17	Let's now replace 100 by 50.
03:22	Let's run again.
03:23	Turtle draws another square with dimension 50.
03:28	Please note that this command can be used only within the scope of this program.
03:35	I will clear the current code from editor.
03:38	Type "clear" command and Run to clean the canvas.
03:44	Next, we will learn about “random” command.
03:48	random command takes input and returns output.
03:52	Syntax for the random command is: “random X,Y”
03:57	where X and Y are two inputs.
04:01	X sets minimum output and Y sets maximum output.
04:07	Output is randomly chosen number between X and Y.
04:13	Let's put the “random” command to use in the application.
04:18	I already have a code in a text-editor.
04:22	I will explain the code now.
04:24	“reset” command sets Turtle to default position.
04:29	Here, the command random 1,20 selects a number which is equal or greater than 1 and equal or less than 20 and assigns it to the variable 'x'.
04:44	repeat command and the commands within curly brackets draw a circle.
04:51	I will copy the code from text editor and paste it into KTurtle's editor.
04:58	Pause the tutorial here and type the program into your KTurtle editor.
05:03	Resume the tutorial after typing the program.
05:08	When we run this code,
05:10	Turtle draws a circle with radius between 1 and 20 on the canvas.
05:16	Let us execute this code a few times.
05:20	You can see that a circle with a different size is generated each time.
05:26	Every time you execute this code, a circle with a different radius is drawn on the canvas.
05:33	Let us now use both learn and random commands in an example.
05:39	I will clear the current code from the editor. Type "clear" command and Run to clean the canvas.
05:48	I already have a program in the Text-editor.
05:52	I will explain the code now.
05:55	“reset” command sets Turtle to its default position.
06:00	canvassize 300,300 sets the width and height of the canvas to 300 pixels each.
06:09	$R, $G and $B are three variables to which I am assigning random values between 0 and 255.
06:19	In the command canvascolor $R, $G and $B,
06:23	the Red-Green-Blue combination is replaced by the values assigned to the variables 'R', 'G' and 'B' in the previous step.
06:34	The canvas color is randomly set when this command is executed.
06:41	$red, $blue, $green are another set of variables
06:45	to which random values between 0 and 255 are assigned randomly.
06:53	pencolor $red, $blue and $green the Red-Blue-Green combination values are replaced by the variables.
07:02	$red, $green and $blue to which random values were assigned in the previous step.
07:10	The color of the pen is also set randomly when the command is executed.
07:18	penwidth 2 sets the width of pen to 2 pixels.
07:25	Next, I have entered the code to learn to draw a circle.
07:30	Here $x represents the size of the circle.
07:35	repeat command followed by the code in curly brackets draws a circle.
07:43	The next set of commands, that is, go command followed by circle command draw circles with the specified sizes.
07:54	For example: circle with size 5, draws a circle with size 5
08:01	at the co-ordinates specified at 'X' and 'Y' positions, in the go command.
08:09	For each circle, I have specified different positions on the canvas.
08:16	I will copy the code from text-editor and paste it into KTurtle's editor.
08:23	Pause the tutorial here and type the program into your KTurtle editor.
08:29	Resume the tutorial after typing the program.
08:33	I will execute this code in Fullspeed.
08:37	You can execute this code at any of the speeds specified in the Run option.
08:43	I will run this code a few times.
08:46	You can see the difference in randomly set values of pen color and canvas color.
08:54	Note the change in the color of the pen and the canvas on each execution.
09:01	You can execute the code how many ever times you want and note the changes in the randomly set values of the pen and canvas.
09:15	With this we come to the end of this tutorial.
09:20	Let's summarize.
09:22	In this tutorial, we have learnt about: “learn” command and “random” command.
09:30	As an assignment for you to solve,
09:32	using learn command- draw a pentagon square rectangle hexagon on all four corners of your canvas and
09:45	a circle at the centre of the canvas.
09:49	Using the “random” command, create various colors and
09:55	customize your geometric shapes and canvas.
10:00	Watch the video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken-Tutorial
10:04	It summarizes the Spoken Tutorial project.
10:08	If you do not have good bandwidth, you can download and watch it.
10:13	The Spoken Tutorial Project team :
10:15	* Conducts workshops using spoken tutorials.
10:19	* Gives certificates to those who pass an online test.
10:22	For more details, please write to: contact@spoken-tutorial.org
10:29	Spoken Tutorial project is a part of the Talk to a Teacher project.
10:33	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
10:40	More information on this mission is available at this link: http://spoken-tutorial.org/NMEICT-Intro
10:46	This script is contributed by IT for change, Bangaluru.
10:50	This is Madhuri Ganpathi from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Krupali, Madhurig, PoojaMoolya, Pratik kamble, Pravin1389, Sandhya.np14, Sneha