Difference between revisions of "Scilab/C2/Getting-Started/English-timed"

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|Welcome to the spoken tutorial on Getting Started with Scilab.

|Welcome to the spoken tutorial on Getting Started with Scilab.

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| In this tutorial we are going to learn:  

| In this tutorial we are going to learn:  

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| The use Scilab as a calculator.

| The use Scilab as a calculator.

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| How to Store values in a variable.

| How to Store values in a variable.

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| How to Perform various mathematical operations using these variables.

| How to Perform various mathematical operations using these variables.

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| How to Create a file to store commands executed during the session in the current working directory.

| How to Create a file to store commands executed during the session in the current working directory.

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| How to define complex numbers.

| How to define complex numbers.

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| How to Perform exponential, logarithmic and trigonometric operations on numbers.

| How to Perform exponential, logarithmic and trigonometric operations on numbers.

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|The prerequisite for this tutorial are Scilab should be installed on your computer.

|The prerequisite for this tutorial are Scilab should be installed on your computer.

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| I am using Scilab 5.2.0 and Mac OS/X  for demonstration

| I am using Scilab 5.2.0 and Mac OS/X  for demonstration

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|Here is the Flow chart for the tutorial.

|Here is the Flow chart for the tutorial.

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|Click on the Scilab shortcut icon on your Desktop and Start Scilab.

|Click on the Scilab shortcut icon on your Desktop and Start Scilab.

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| This is the Scilab console window. Notice that the cursor is on the command prompt.

| This is the Scilab console window. Notice that the cursor is on the command prompt.

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| I suggest that you practice this tutorial in Scilab simultaneously while pausing the video at regular intervals of time.

| I suggest that you practice this tutorial in Scilab simultaneously while pausing the video at regular intervals of time.

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|Scilab can be used as a calculator.  

|Scilab can be used as a calculator.  

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|Let us see some of the basic operations that it can do.

|Let us see some of the basic operations that it can do.

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| Type 42 plus 4 multiplied by 4 minus 64 divided 4 and press enter.

| Type 42 plus 4 multiplied by 4 minus 64 divided 4 and press enter.

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| The output is 42, as expected.

| The output is 42, as expected.

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|Note that the answer 42 is stored in the default variable "a n s".

|Note that the answer 42 is stored in the default variable "a n s".

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|We can also create named variables: Type,  

|We can also create named variables: Type,  

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| a equals 12, b=21 , c=33 and press enter.

| a equals 12, b=21 , c=33 and press enter.

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| This stores the values 12, 21 and 33 in the variables a, b and c respectively.

| This stores the values 12, 21 and 33 in the variables a, b and c respectively.

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| I will clear the scilab console using the clc command here

| I will clear the scilab console using the clc command here

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|Now we will perform some mathematical operations using these variables.  

|Now we will perform some mathematical operations using these variables.  

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| For example,

| For example,

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| a+b+c gives the result 66  

| a+b+c gives the result 66  

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|also

|also

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| a times into bracket  

| a times into bracket  

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| b plus c  gives the result 648

| b plus c  gives the result 648

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|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  

|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  

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| d = 1089.

| d = 1089.

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|We can check the values in the variables by typing the names of the variables separated by commas on the command line as  

|We can check the values in the variables by typing the names of the variables separated by commas on the command line as  

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| a,b,c,d and press enter

| a,b,c,d and press enter

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| I will clear the console here using the clc command

| I will clear the console here using the clc command

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|To take the power, use the “raised to” symbol which is located on the number key 6 of your keyboard.

|To take the power, use the “raised to” symbol which is located on the number key 6 of your keyboard.

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|Press ' shift key' and number key 6 to used this symbol.

|Press ' shift key' and number key 6 to used this symbol.

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| for example, 7 square can be found by 7 raised to 2 and press Enter.

| for example, 7 square can be found by 7 raised to 2 and press Enter.

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|For finding the square root of a number, say, 17, we use : sqrt of 17

|For finding the square root of a number, say, 17, we use : sqrt of 17

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|This is same as 17 raised to the power of zero point five.  

|This is same as 17 raised to the power of zero point five.  

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|By convention, only the positive value comes as output.

|By convention, only the positive value comes as output.

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| More generally, to find 34 to the power of (2 by 5), type:

| More generally, to find 34 to the power of (2 by 5), type:

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|34 raised to bracket  2 divide by 5  close the bracket and press Enter.

|34 raised to bracket  2 divide by 5  close the bracket and press Enter.

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| Negative powers can also be used,

| Negative powers can also be used,

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| Clear the cansole using clc command

| Clear the cansole using clc command

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| So far, you  have seen how to do some simple calculations and how to create variables in Scilab.

| So far, you  have seen how to do some simple calculations and how to create variables in Scilab.

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| Now let us start with the new command.

| Now let us start with the new command.

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| This will helps remember command which were previously issued along with the outputs.

| This will helps remember command which were previously issued along with the outputs.

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| First type the command pwd and press Enter

| First type the command pwd and press Enter

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| This is the current working directory (on my computer).  

| This is the current working directory (on my computer).  

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|It might be different on your computer

|It might be different on your computer

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|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.

|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.

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|Now issue the diary command by typing:

|Now issue the diary command by typing:

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| diary bracket, open inverted commas,  myrecord.txt  close inverted commas, close the bracket and press enter'''

| diary bracket, open inverted commas,  myrecord.txt  close inverted commas, close the bracket and press enter'''

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|This command will create a file with the name "myrecord.txt" in the current working directory.  

|This command will create a file with the name "myrecord.txt" in the current working directory.  

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| A transcript of the Scilab session from now onwards will be saved in this file.  

| A transcript of the Scilab session from now onwards will be saved in this file.  

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| Its usefulness will be demonstrated at a later stage in this tutorial.

| Its usefulness will be demonstrated at a later stage in this tutorial.

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|Please pause the tutorial now and attempt exercise number one given with the video.  

|Please pause the tutorial now and attempt exercise number one given with the video.  

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|Now, let us see how Scilab handles complex numbers.  

|Now, let us see how Scilab handles complex numbers.  

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| The imaginary unit i is defined in Scilab as percent i:

| The imaginary unit i is defined in Scilab as percent i:

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| For example,Five point two multiplied percent i gives 5.2i

| For example,Five point two multiplied percent i gives 5.2i

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|also bracket  10 plus 5 into percent i whole multiply by 2 times percent i gives the result -10. + 20.i

|also bracket  10 plus 5 into percent i whole multiply by 2 times percent i gives the result -10. + 20.i

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| Now clear the console here,

| Now clear the console here,

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|Let us see some other predefined numerical constants available in Scilab.

|Let us see some other predefined numerical constants available in Scilab.

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| As with i, their names also start with the percent sign:

| As with i, their names also start with the percent sign:

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| For example, percent pi.

| For example, percent pi.

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| The value of pi is as expected.

| The value of pi is as expected.

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|Now, we will demonstrate the use of pi using a few built-in trigonometric functions as follows.  

|Now, we will demonstrate the use of pi using a few built-in trigonometric functions as follows.  

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| For the functions sin of percent pi by 2 the result is 1

| For the functions sin of percent pi by 2 the result is 1

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|''And for cos of percent pi by 2 the result is 6.123D-17.'''

|''And for cos of percent pi by 2 the result is 6.123D-17.'''

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|Please note that the angles are measured in radians and

|Please note that the angles are measured in radians and

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| Notice that the second answer is zero for all practical purposes.  

| Notice that the second answer is zero for all practical purposes.  

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| %eps is related to number known as "machine epsilon",

| %eps is related to number known as "machine epsilon",

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| It is the minimum digit resolution that Scilab can give.

| It is the minimum digit resolution that Scilab can give.

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|Type % eps on your console to find its value on your computer.

|Type % eps on your console to find its value on your computer.

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| On my computer it gives 2.220D-16  

| On my computer it gives 2.220D-16  

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| This shows the floating point precision used by Scilab .  

| This shows the floating point precision used by Scilab .  

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| This number is a notation for 2.22 times 10^(-16). Clear the console here.

| This number is a notation for 2.22 times 10^(-16). Clear the console here.

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|If one wants to write 0.000456, one can write it as 4.56d-4 or 4.56e-4.

|If one wants to write 0.000456, one can write it as 4.56d-4 or 4.56e-4.

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|While scilab variables and functions are case-sensitive, here we can use small d or capital D, or small e, or capital E.  

|While scilab variables and functions are case-sensitive, here we can use small d or capital D, or small e, or capital E.  

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|The base of the natural logarithm is another important predefined numerical constant:

|The base of the natural logarithm is another important predefined numerical constant:

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| percent e gives the result as expected.  

| percent e gives the result as expected.  

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|We can achieve the same result with the function "e x p''.

|We can achieve the same result with the function "e x p''.

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| For example: exp bracket (1)'' close the bracket and press Enter

| For example: exp bracket (1)'' close the bracket and press Enter

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| You can see both the answers are same

| You can see both the answers are same

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|Clear the console using the clc command here.

|Clear the console using the clc command here.

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|similarly,

|similarly,

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| %e square gives the following answer

| %e square gives the following answer

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|which can also be achieved by typing exp of 2 .  

|which can also be achieved by typing exp of 2 .  

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|The command log means the natural logarithm of a number, that is, to the base e.  

|The command log means the natural logarithm of a number, that is, to the base e.  

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| Use log 10 for taking the logarithm with respect to base 10.  

| Use log 10 for taking the logarithm with respect to base 10.  

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| For example, log10 bracket 1e minus 23 close bracket  and press enter this gives the expected answer -23.

| For example, log10 bracket 1e minus 23 close bracket  and press enter this gives the expected answer -23.

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| We get complex numbers when taking logarithm of negative.  

| We get complex numbers when taking logarithm of negative.  

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| For complex numbers you can check this for yourself type : log of -1 or log of %i on your scilab console.

| For complex numbers you can check this for yourself type : log of -1 or log of %i on your scilab console.

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|Now recall that we invoked a recording of all the typed commands into the file myrecord.txt through the diary command,  

|Now recall that we invoked a recording of all the typed commands into the file myrecord.txt through the diary command,  

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|Now, let's see how to close that file and view it.  

|Now, let's see how to close that file and view it.  

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| For closing the file, type,

| For closing the file, type,

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| diary of zero

| diary of zero

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| This command will close and save the file myrecord.txt.  

| This command will close and save the file myrecord.txt.  

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| Also recall that this file was created in current working directory, which in my case is desktop.  

| Also recall that this file was created in current working directory, which in my case is desktop.  

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|Let us open this file to do click on the a Open-a-file shortcut icon on your scilab console window toolbar.

|Let us open this file to do click on the a Open-a-file shortcut icon on your scilab console window toolbar.

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| I will change the file format to all file

| I will change the file format to all file

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|Select the file myrecord.txt and click on Open.

|Select the file myrecord.txt and click on Open.

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|Note that all transactions, both commands and the corresponding answers given by Scilab, have been saved into this file.

|Note that all transactions, both commands and the corresponding answers given by Scilab, have been saved into this file.

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|I will close this file.

|I will close this file.

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|Click yes.

|Click yes.

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|We know that, while a program is being developed, one experiments a lot with the code before arriving at suitable code.  

|We know that, while a program is being developed, one experiments a lot with the code before arriving at suitable code.  

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|Diary command helps to keep track of all the transactions.

|Diary command helps to keep track of all the transactions.

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| If you recall that, we had closed the file my record.txt using the command diary of zero.

| If you recall that, we had closed the file my record.txt using the command diary of zero.

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| Please , note that no transactions can be saved after executing this command.

| Please , note that no transactions can be saved after executing this command.

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|If we need to save the session once again, we need to issue the diary command again.  

|If we need to save the session once again, we need to issue the diary command again.  

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|If the file contains some useful information, then one should use the some other file name in the diary command.

|If the file contains some useful information, then one should use the some other file name in the diary command.

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| Because, use of same file name will overwrite the existing file.

| Because, use of same file name will overwrite the existing file.

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|Pause the video here and solve the second exercise given with the video.

|Pause the video here and solve the second exercise given with the video.

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|You may have noticed that the solution for the problem was not exactly zero.

|You may have noticed that the solution for the problem was not exactly zero.

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| For more information on how to deal with this, type “help clean”.

| For more information on how to deal with this, type “help clean”.

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|In general, if you need help about a particular command, then the 'help' or help with an argument command can be used.

|In general, if you need help about a particular command, then the 'help' or help with an argument command can be used.

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| For example, type “help chdir” on the scilab console and press enter.

| For example, type “help chdir” on the scilab console and press enter.

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| I will increase the size of the help browser.

| I will increase the size of the help browser.

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| Help chdir gives detailed information on how to change the current working directory.

| Help chdir gives detailed information on how to change the current working directory.

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| Another option is to click on the help browser icon on the toolbar of the scilab console window as you see.

| Another option is to click on the help browser icon on the toolbar of the scilab console window as you see.

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| Let me close the help browser and coming back to the slides.

| Let me close the help browser and coming back to the slides.

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| The up - down arrow keys can been used to see the previously executed commands.

| The up - down arrow keys can been used to see the previously executed commands.

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|While using the up - down arrows, you can stop at any command,and press Enter to execute it.

|While using the up - down arrows, you can stop at any command,and press Enter to execute it.

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| You can edit the commands, if necessary.

| You can edit the commands, if necessary.

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| 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.

| 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.

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|Use tab key to auto-complete the commad. It gives us all the available options to choose.  

|Use tab key to auto-complete the commad. It gives us all the available options to choose.  

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|In this tutorial we have learnt :

|In this tutorial we have learnt :

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|Use of Scilab as a calculator .

|Use of Scilab as a calculator .

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| Store the result in the default variable ans.  

| Store the result in the default variable ans.  

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| Assign values to the variable using the equality sign.

| Assign values to the variable using the equality sign.

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| Check values in variables by typing the name of the variable separated by commas on the console.

| Check values in variables by typing the name of the variable separated by commas on the console.

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| Check the current working directory using pwd command.

| Check the current working directory using pwd command.

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| Use diary command to save all commands typed on the console into a file.

| Use diary command to save all commands typed on the console into a file.

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| Define complex numbers, natural exponents and π using %i, %e and %pi respectively.  

| Define complex numbers, natural exponents and π using %i, %e and %pi respectively.  

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| Use help command for detailed information about any command.

| Use help command for detailed information about any command.

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|This brings us to the end of this spoken tutorial on Getting Started with Scilab.

|This brings us to the end of this spoken tutorial on Getting Started with Scilab.

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| There are many other functions in Scilab which will be covered in other spoken tutorials.

| There are many other functions in Scilab which will be covered in other spoken tutorials.

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| This spoken tutorial has been created by the Free and Open Source Software in Science and Engineering Education(FOSSEE).  

| This spoken tutorial has been created by the Free and Open Source Software in Science and Engineering Education(FOSSEE).  

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| More information on the FOSSEE project could be obtained from http://fossee.in or http://scilab.in website  

| More information on the FOSSEE project could be obtained from http://fossee.in or http://scilab.in website  

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

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

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| More information on this please visit spoken hyphen tutorial dot org slash NMEICT hyphen intro

| More information on this please visit spoken hyphen tutorial dot org slash NMEICT hyphen intro

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|I hope you find this spoken tutorial useful for learning.

|I hope you find this spoken tutorial useful for learning.

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| Thank you.

| Thank you.

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| This is Anuradha Amrutkar from IIT Bombay signing off.

| This is Anuradha Amrutkar from IIT Bombay signing off.