Scilab/C2/Getting-Started/English-timed

Time	Narration
00:02	Welcome to the spoken tutorial on Getting Started with Scilab.
00:07	In this tutorial we are going to learn:
00:09	The use of Scilab as a calculator.
00:12	How to store values in a variable.
00:15	How to perform various mathematical operations using these variables.
00:21	How to create a file, to store commands executed during the session, in the current working directory.
00:29	How to define complex numbers.
00:31	How to perform exponential, logarithmic and trigonometric operations on numbers.
00:38	The prerequisite for this tutorial is- Scilab should be installed on your computer.
00:44	I am using Scilab 5.2.0 and Mac OS/X for demonstration.
00:51	Here is the Flow chart for the tutorial.
00:55	Click on the Scilab shortcut icon on your Desktop and Start Scilab.
01:01	This is the Scilab console window. Notice that the cursor is on the command prompt.
01:07	I suggest that you practice this tutorial in Scilab simultaneously while pausing the video at regular intervals of time.
01:16	Scilab can be used as a calculator.
01:19	Let us see some of the basic operations that it can do.
01:25	Type 42 plus 4 multiplied by 4 minus 64 divided by 4 and press Enter.
01:36	The output is 42, as expected.
01:39	Note that the answer 42 is stored in the default variable "a n s".
01:45	We can also create named variables: Type,
01:49	a equals 12, b=21 , c=33 and press Enter.
02:00	This stores the values 12, 21 and 33 in the variables a, b and c respectively.
02:08	I will clear the scilab console using the clc command here.
02:13	Now we will perform some mathematical operations using these variables.
02:19	For example,
02:21	a+b+c gives the result 66;
02:27	also
02:29	a times into bracket
02:35	b plus c gives the result 648.
02:41	We can also assign the answer to another variable say 'd' by typing d = bracket a+b close the bracket multiplied by c gives the answer
02:58	d = 1089.
03:01	We can check the values in the variables by typing the names of the variables separated by commas on the command line as
03:09	a,b,c,d and press Enter.
03:16	I will clear the console here using the clc command.
03:21	To take the power, use the “raised to” symbol which is located on the number key 6 of your keyboard.
03:29	Press ' Shift key' and number key 6 to use this symbol.
03:34	for example, 7 square can be found by 7 raised to 2 and press Enter.
03:43	For finding the square root of a number, say, 17, we use : sqrt of 17
03:55	This is same as 17 raised to the power of zero point five.
04:06	By convention, only the positive value comes as output.
04:10	More generally, to find 34 to the power of (2 by 5), type:
04:15	34 raised to bracket 2 divided by 5 close the bracket and press Enter.
04:25	Negative powers can also be used.
04:28	Clear the cansole using clc command.
04:33	So far, you have seen how to do some simple calculations and how to create variables in Scilab.
04:40	Now let us start with the new command.
04:43	This will help remember commands which were previously issued along with the outputs.
04:49	First, type the command pwd and press Enter.
04:55	This is the current working directory (on my computer).
04:58	It might be different on your computer.
05:01	The current working directory can be changed by clicking the changed current directory icon, located on the toolbar of the scilab console window as you see.
05:15	Now issue the diary command by typing:
05:20	diary bracket, open inverted commas, myrecord.txt close inverted commas, close the bracket and press Enter.
05:40	This command will create a file with the name "myrecord.txt" in the current working directory.
05:48	A transcript of the Scilab session from now onwards will be saved in this file.
05:53	Its usefulness will be demonstrated at a later stage in this tutorial.
06:00	Please pause the tutorial now and attempt exercise number one given with the video.
06:07	Now, let us see how Scilab handles complex numbers.
06:13	The imaginary unit i is defined in Scilab as percent i:
06:18	For example,Five point two multiplied percent i gives 5.2i;
06:29	also bracket 10 plus 5 into percent i whole multiply by 2 times percent i gives the result -10. + 20.i
06:58	Now clear the console here.
07:04	Let us see some other predefined numerical constants available in Scilab.
07:09	As with i, their names also start with the percent sign:
07:13	For example, percent pi.
07:18	The value of pi is as expected.
07:21	Now, we will demonstrate the use of pi using a few built-in trigonometric functions as follows.
07:27	For the functions sine of percent pi by 2 the result is 1.
07:37	And for cos of percent pi by 2 the result is 6.123D-17.
07:50	Please note that the angles are measured in radians and
07:54	notice that the second answer is zero for all practical purposes.
07:59	%eps is related to number known as "machine epsilon",
08:03	It is the minimum digit resolution that Scilab can give.
08:08	Type % eps on your console to find its value on your computer.
08:19	On my computer it gives 2.220D-16
08:24	This shows the floating point precision used by Scilab .
08:28	This number is a notation for 2.22 times 10^(-16). Clear the console here.
08:41	If one wants to write 0.000456, one can write it as 4.56d-4 or 4.56e-4.
09:06	While scilab variables and functions are case-sensitive, here we can use small d or capital D, or small e, or capital E.
09:16	The base of the natural logarithm is another important predefined numerical constant:
09:22	percent e gives the result as expected.
09:30	We can achieve the same result with the function "e x p.
09:35	For example: exp bracket (1) close the bracket and press Enter
09:44	You can see both the answers are same
09:47	Clear the console using the clc command here.
09:55	similarly,
09:56	%e square gives the following answer
10:04	which can also be achieved by typing exp of 2 .
10:18	The command log means the natural logarithm of a number, that is, to the base e.
10:23	Use log 10 for taking the logarithm with respect to base 10.
10:29	For example, log10 bracket 1e minus 23 close bracket and press enter this gives the expected answer -23.
10:47	We get complex numbers when taking logarithm of negative.
10:51	For complex numbers you can check this for yourself type : log of -1 or log of %i on your scilab console.
11:01	Now recall that we invoked a recording of all the typed commands into the file myrecord.txt through the diary command,
11:09	Now, let's see how to close that file and view it.
11:13	For closing the file, type,
11:16	diary of zero
11:21	This command will close and save the file myrecord.txt.
11:26	Also recall that this file was created in current working directory, which in my case is desktop.
11:34	Let us open this file to do click on the a Open-a-file shortcut icon on your scilab console window toolbar.
11:46	I will change the file format to all file
11:51	Select the file myrecord.txt and click on Open.
11:59	Note that all transactions, both commands and the corresponding answers given by Scilab, have been saved into this file.
12:10	I will close this file.
12:15	Click yes.
12:21	We know that, while a program is being developed, one experiments a lot with the code before arriving at suitable code.
12:29	Diary command helps to keep track of all the transactions.
12:35	If you recall that, we had closed the file my record.txt using the command diary of zero.
12:42	Please , note that no transactions can be saved after executing this command.
12:48	If we need to save the session once again, we need to issue the diary command again.
12:54	If the file contains some useful information, then one should use the some other file name in the diary command.
13:03	Because, use of same file name will overwrite the existing file.
13:09	Pause the video here and solve the second exercise given with the video.
13:15	You may have noticed that the solution for the problem was not exactly zero.
13:21	For more information on how to deal with this, type “help clean”.
13:27	In general, if you need help about a particular command, then the 'help' or help with an argument command can be used.
13:37	For example, type “help chdir” on the scilab console and press enter.
13:53	I will increase the size of the help browser.
14:01	Help chdir gives detailed information on how to change the current working directory.
14:10	Another option is to click on the help browser icon on the toolbar of the scilab console window as you see.
14:20	Let me close the help browser and coming back to the slides.
14:31	The up - down arrow keys can been used to see the previously executed commands.
14:36	While using the up - down arrows, you can stop at any command,and press Enter to execute it.
14:45	You can edit the commands, if necessary.
14:48	In fact, you are looking for a previous command you typed, which started with the letter 'e', then type e, and then use up arrow key.
14:59	Use tab key to auto-complete the commad. It gives us all the available options to choose.
15:07	In this tutorial we have learnt :
15:10	Use of Scilab as a calculator .
15:12	Store the result in the default variable ans.
15:16	Assign values to the variable using the equality sign.
15:20	Check values in variables by typing the name of the variable separated by commas on the console.
15:28	Check the current working directory using pwd command.
15:34	Use diary command to save all commands typed on the console into a file.
15:40	Define complex numbers, natural exponents and π using %i, %e and %pi respectively.
15:49	Use help command for detailed information about any command.
15:54	This brings us to the end of this spoken tutorial on Getting Started with Scilab.
15:59	There are many other functions in Scilab which will be covered in other spoken tutorials.
16:06	This spoken tutorial has been created by the Free and Open Source Software in Science and Engineering Education(FOSSEE).
16:14	More information on the FOSSEE project could be obtained from http://fossee.in or http://scilab.in website
16:22	Supported by the National Mission on Eduction through ICT, MHRD, Government of India.
16:29	More information on this please visit spoken hyphen tutorial dot org slash NMEICT hyphen intro
16:43	I hope you find this spoken tutorial useful for learning.
16:47	Thank you.
16:48	This is Anuradha Amrutkar from IIT Bombay signing off.

Contributors and Content Editors

Gaurav, Jyotisolanki, Krupali, PoojaMoolya, Sandhya.np14, Sneha