Difference between revisions of "Scilab/C4/File-handling/English-timed"
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Sandhya.np14 (Talk | contribs) |
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|00:11 | |00:11 | ||
− | |''' | + | |'''write()''' function |
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| 00:12 | | 00:12 | ||
− | |''' | + | |'''read''' function |
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|00:14 | |00:14 | ||
− | |'''mopen''' | + | |'''mopen()''' |
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|00:15 | |00:15 | ||
− | |'''mclose''' | + | |'''mclose()'''. |
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| 00:16 | | 00:16 | ||
− | |For demonstration I am using '''Ubuntu Linux 12.04''' operating system with '''Scilab''' version 5.3.3 installed. | + | |For demonstration, I am using '''Ubuntu Linux 12.04''' operating system with '''Scilab''' version 5.3.3 installed. |
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|01:07 | |01:07 | ||
− | |Switch to the | + | |Switch to the Scilab console window. |
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| 01:15 | | 01:15 | ||
− | || Type | + | || Type: ''' random underscore matrix is equal to rand into bracket 20 comma 1 close the bracket semicolon''' and press '''Enter'''. |
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|01:32 | |01:32 | ||
− | || Type '''pwd ''' | + | || Type '''pwd '''. |
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|01:34 | |01:34 | ||
− | | In my case the present working directory is '''slash home slash fossee ''' | + | | In my case, the present working directory is '''slash home slash fossee '''. |
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|01:39 | |01:39 | ||
− | | Make sure that you are in a directory where you have read & write permission , before you execute these commands. | + | | Make sure that you are in a directory where you have '''read''' & '''write''' permission, before you execute these commands. |
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|01:47 | |01:47 | ||
− | || Now we will write the content of variable '''random underscore matrix''' into a text file using the write command. | + | || Now we will write the content of variable '''random underscore matrix''' into a text file using the '''write''' command. |
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|01:55 | |01:55 | ||
− | | Type | + | | Type:--> '''write into bracket into quotes random dash numbers dot txt close the quotes comma random underscore matrix close the bracket''' and press '''Enter'''. |
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| 02:21 | | 02:21 | ||
− | ||I will minimize the ''' | + | ||I will minimize the '''Scilab''' console window. |
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| 02:23 | | 02:23 | ||
− | |And open the file which will be created and saved in the fossee directory of my computer. | + | |And open the file which will be created and saved in the '''fossee''' directory of my computer. |
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| 02:33 | | 02:33 | ||
− | || You can see the data from variable '''random underscore matrix is written in a text file random dash numbers dot txt''' | + | || You can see the data from variable '''random underscore matrix''' is written in a text file '''random dash numbers dot txt'''. |
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|02:45 | |02:45 | ||
− | | Coming back to the | + | | Coming back to the '''Scilab''' console. |
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| 02:50 | | 02:50 | ||
− | || For this we will use the command read as follows | + | || For this we will use the command '''read''' as follows: |
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| 02:55 | | 02:55 | ||
− | | Type '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt close the quotes comma 20 comma 1 close the bracket and press | + | | Type: '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt close the quotes comma 20 comma 1 close the bracket''' and press '''Enter'''. |
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|03:18 | |03:18 | ||
− | | The read command reads all the data from the file mentioned in the argument, | + | | The '''read''' command reads all the data from the file mentioned in the argument, |
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| 03:23 | | 03:23 | ||
− | | | + | | in this case '''random dash numbers dot txt''', |
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| 03:27 | | 03:27 | ||
− | | | + | | and stores in the variable '''new underscore vector'''. |
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| 03:31 | | 03:31 | ||
− | | Press Enter to continue the display | + | | Press '''Enter''' to continue the display. |
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|03:35 | |03:35 | ||
− | | If we modify the above command as | + | | If we modify the above command as: |
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|03:39 | |03:39 | ||
− | | '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1 ''' | + | | '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1''' |
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| 03:49 | | 03:49 | ||
− | | The read command reads only 19 data values from the file mentioned in this argument | + | | The '''read''' command reads only 19 data values from the file mentioned in this argument, |
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| 03:56 | | 03:56 | ||
− | | | + | |in this case '''random dash numbers dot txt''', |
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| 03:59 | | 03:59 | ||
− | || | + | ||and stores in the variable '''new underscore vector'''. |
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| 04:03 | | 04:03 | ||
− | | |Issue this command on the ''' | + | | |Issue this command on the '''Scilab''' console and verify the output. |
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|04:08 | |04:08 | ||
− | ||Now let us see about the mopen function: | + | ||Now let us see about the '''mopen()''' function: |
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| 04:17 | | 04:17 | ||
− | |mopen command is used to open an existing file in a way compatible to C fopen procedure. | + | |'''mopen''' command is used to open an existing file in a way compatible to C '''fopen''' procedure. |
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| 04:25 | | 04:25 | ||
− | | mode is a character string that controls whether the file is opened for | + | | '''mode''' is a character string that controls whether the file is opened for: |
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|04:30 | |04:30 | ||
− | | r = | + | | r = opens the file for reading. |
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|04:34 | |04:34 | ||
− | | rb = | + | | rb = opens a binary file for reading. |
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| 04:39 | | 04:39 | ||
− | | rt = | + | | rt = opens a text file for reading. |
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|04:43 | |04:43 | ||
− | ||w = | + | ||w = creates a new file for writing or opens and truncates a file to zero length. |
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|04:50 | |04:50 | ||
− | | wb = | + | | wb = creates a new binary file for writing or opens and truncates a file to zero length. |
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| 04:58 | | 04:58 | ||
− | | |wt = | + | | |wt = creates a text binary file for writing or opens and truncates a file to zero length. |
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| 05:06 | | 05:06 | ||
− | |a or ab = | + | |a or ab = appends (opens a file for writing at the end of the file or creates a file for writing). |
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| 05:14 | | 05:14 | ||
− | | r+ or r+b = | + | | r+ or r+b = opens a file for update (reading and writing). |
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| 05:20 | | 05:20 | ||
− | | For eg '''fd underscore r is equal to mopen('random-numbers,'rt')''' | + | | For eg. '''fd underscore r is equal to mopen('random-numbers,'rt')''' |
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| 05:30 | | 05:30 | ||
− | || | + | ||The above command opens the 'random-numbers' as a 'text and read-only' mode. |
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| 05:37 | | 05:37 | ||
− | ||'''mclose into bracket fd''': | + | ||'''mclose''' into bracket '''fd''': |
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| 05:40 | | 05:40 | ||
− | || closes the opened file by using mopen | + | || closes the opened file by using '''mopen''' |
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| 05:43 | | 05:43 | ||
− | |where fd is the file descriptor of the opened file | + | |where '''fd''' is the '''file descriptor''' of the opened file. |
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| 05:48 | | 05:48 | ||
− | | If fd is omitted mclose closes the last opened file. | + | | If '''fd''' is omitted, '''mclose()''' closes the last opened file. |
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| 05:56 | | 05:56 | ||
− | | File | + | | File handling with the following functions: |
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| 06:00 | | 06:00 | ||
− | | ''' | + | | '''read()''' function |
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| 06:02 | | 06:02 | ||
− | | '''mopen''' | + | | '''mopen()''' |
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| 06:03 | | 06:03 | ||
− | | '''mclose'''. | + | | '''mclose()'''. |
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Revision as of 22:02, 26 February 2015
Time | Narration |
00:01 | Welcome to this spoken tutorial on File Handling using Scilab. |
00:06 | In this tutorial, we will learn |
00:08 | file handling with the following functions: |
00:11 | write() function |
00:12 | read function |
00:14 | mopen() |
00:15 | mclose(). |
00:16 | For demonstration, I am using Ubuntu Linux 12.04 operating system with Scilab version 5.3.3 installed. |
00:26 | You should have basic knowledge of Scilab. |
00:29 | If not, for relevant spoken tutorials please visit spoken hyphen tutorial dot org. |
00:36 | Now we will see some functions in Scilab which are useful for file handling. |
00:41 | File handling involves- |
00:44 | writing to a file using write() function, |
00:47 | reading from a file using read() function, |
00:51 | opening an existing file using mopen() function and |
00:55 | closing an already opened file using mclose() function. |
01:00 | Let us start with writing data to a file. |
01:03 | For this purpose the write() command is used. |
01:07 | Switch to the Scilab console window. |
01:10 | To begin with let us create a matrix of random numbers. |
01:15 | Type: random underscore matrix is equal to rand into bracket 20 comma 1 close the bracket semicolon and press Enter. |
01:29 | Now check the present working directory. |
01:32 | Type pwd . |
01:34 | In my case, the present working directory is slash home slash fossee . |
01:39 | Make sure that you are in a directory where you have read & write permission, before you execute these commands. |
01:47 | Now we will write the content of variable random underscore matrix into a text file using the write command. |
01:55 | Type:--> write into bracket into quotes random dash numbers dot txt close the quotes comma random underscore matrix close the bracket and press Enter. |
02:18 | Let us see whether this file has been created. |
02:21 | I will minimize the Scilab console window. |
02:23 | And open the file which will be created and saved in the fossee directory of my computer. |
02:33 | You can see the data from variable random underscore matrix is written in a text file random dash numbers dot txt. |
02:42 | I will close this file. |
02:45 | Coming back to the Scilab console. |
02:47 | Now we will see how to read the data from a file. |
02:50 | For this we will use the command read as follows: |
02:55 | Type: new underscore vector is equal to read into bracket into quote random dash numbers dot txt close the quotes comma 20 comma 1 close the bracket and press Enter. |
03:18 | The read command reads all the data from the file mentioned in the argument, |
03:23 | in this case random dash numbers dot txt, |
03:27 | and stores in the variable new underscore vector. |
03:31 | Press Enter to continue the display. |
03:35 | If we modify the above command as: |
03:39 | new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1 |
03:49 | The read command reads only 19 data values from the file mentioned in this argument, |
03:56 | in this case random dash numbers dot txt, |
03:59 | and stores in the variable new underscore vector. |
04:03 | Issue this command on the Scilab console and verify the output. |
04:08 | Now let us see about the mopen() function: |
04:12 | fd = mopen into bracket file-name comma mode |
04:17 | mopen command is used to open an existing file in a way compatible to C fopen procedure. |
04:25 | mode is a character string that controls whether the file is opened for: |
04:30 | r = opens the file for reading. |
04:34 | rb = opens a binary file for reading. |
04:39 | rt = opens a text file for reading. |
04:43 | w = creates a new file for writing or opens and truncates a file to zero length. |
04:50 | wb = creates a new binary file for writing or opens and truncates a file to zero length. |
04:58 | wt = creates a text binary file for writing or opens and truncates a file to zero length. |
05:06 | a or ab = appends (opens a file for writing at the end of the file or creates a file for writing). |
05:14 | r+ or r+b = opens a file for update (reading and writing). |
05:20 | For eg. fd underscore r is equal to mopen('random-numbers,'rt') |
05:30 | The above command opens the 'random-numbers' as a 'text and read-only' mode. |
05:37 | mclose into bracket fd: |
05:40 | closes the opened file by using mopen |
05:43 | where fd is the file descriptor of the opened file. |
05:48 | If fd is omitted, mclose() closes the last opened file. |
05:53 | That's all we have in this tutorial. |
05:55 | We have learnt - |
05:56 | File handling with the following functions: |
05:59 | write() function |
06:00 | read() function |
06:02 | mopen() |
06:03 | mclose(). |
06:05 | Watch the video available at the following link. |
06:08 | It summarizes the Spoken Tutorial project. |
06:11 | If you do not have good bandwidth, you can download and watch it. |
06:14 | The spoken tutorial Team: |
06:17 | Conducts workshops using spoken tutorials |
06:20 | Gives certificates to those who pass an online test. |
06:23 | For more details, please write to conatct@spoken-tutorial.org. |
06:30 | Spoken Tutorial Project is a part of the Talk to a Teacher project. |
06:34 | It is supported by the National Mission on Eduction through ICT, MHRD, Government of India. |
06:41 | More information on this mission is available at http://spoken-tutorial.org/NMEICT-Intro. |
06:50 | This is Anuradha Amrutkar from IIT Bombay, signing off. |
06:54 | Thank you for joining. |