Difference between revisions of "Scilab/C2/Iteration/English-timed"

| | Welcome to the spoken tutorial on iterative calculations using Scilab.

| | I am using scilab version 5.2 in Mac operating system ,

| | but these calculations should work in other versions and also in Scilab that runs in linux and windows.

| | I will use the code available in the file iteration.sce

|| I have opened this file using Scilab editor, which I plan to use only as an editor.

|| Let us create a vector using the colon operator i is equal to 1 colon 5.

| | In this command,  i is equal to 1 colon 2 colon 5,

| | 1 is the first argument where the vector starts. I cannot go beyond 5.

| |It can be equal to 5, however.

| | It is not difficult to explain this behaviour.

|We will now demonstrate the use of the for statement to perform iterative calculations.

|for i is equal to 1 colon 2 colon 7 disp i end of for loop.

| |I will cut this paste in scilab console press enter.

| |This code prints out i, as we go through the loop.

| |The display is due to the command disp - the passed argument is displayed.

| |Recall that the for loop is used for integer values.

| |The number of times the iterations take place is known as priori in for loops.

| |Let us begin with the loop that displays i equal to 1 to 5.

| | We will modify this code by introducing the break statement.

| Note that i is displayed only up to 2.

| | When i is equal to 2, the if block is executed for the first time.

| | The break command, however, terminates the loop.

|| If we want to get out of a loop when some intermediate condition is satisfied, we can use the break statement.

| | The result of this comparison statement is a boolean: true or false.

| | We will introduce the continue statement here paste press enter

|| This results in i getting displayed only for 4 and 5.

| | For i less than or equal to 3, as given by the i less than or equal to 3 statement, nothing happens.

| | The continue statement makes the program skip the rest of the loop.

| Unlike the break statement, however, it does not exit the loop.

| | The parameter i is incremented and all the calculations of the loop are executed for the new i.

| | We take a small break and show how to get help for operators of the type less than or equal to.

| |Let us type less than or equal to with help

|| This opens the scilab help browser.

|| We see that the help is available under the option less.

| | So now after closing this we type help less

|| We see the required help instructions here. I will close this.

| | The for statement in Scilab is more powerful than in programming languages.

| | For example, let us perform a loop over a vector:

| | This script displays all values of v.

| | We have spent quite a bit of time explaining the for loop.

| | Let us now move on to the while loops.

| | The while statement allows us to perform a loop when a boolean expression is true

| | At the beginning of the loop, if the expression is true,

| |the statements in the body of the while loop are executed.

| | If the program is written well, the expression becomes false and the loop is ended.

|| Now let us see an example for the while loop:

| | The values of i, from 1 to 6 are displayed.

|| Break and continue statements inside the while loop work exactly as they did in the for loop, as we demonstrate using break:

| | We can see that the moment i becomes equal to 3, the program exits the loop, thanks to the break statement.

|| You can also try the example for continue statement in while loop.

| | This brings us to the end of this spoken tutorial on iterative calculations using Scilab.

| |Thanks for joining.Good bye.