Scilab/C4/Integration/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Dear Friends, |
| 00:02. | Welcome to the Spoken Tutorial on “ Composite Numerical Integration” |
| 00:07 | At the end of this tutorial, you will learn how to: |
| 00:11 | Develop Scilab code for different Composite Numerical Integration algorithms |
| 00:17 | Divide the integral into equal intervals |
| 00:21 | Apply the algorithm to each interval and |
| 00:24 | Calculate the composite value of the integral |
| 00:28 | To record this tutorial, I am using |
| 00:30 | Ubuntu 12.04 as the operating system |
| 00:34 | with Scilab 5.3.3 version |
| 00:38 | Before practising this tutorial, a learner should have basic knowledge of |
| 00:42 | Scilab and |
| 00:44 | Integration using Numerical Methods |
| 00:47 | For Scilab, please refer to the relevant tutorials available on the Spoken Tutorial website. |
| 00:55 | Numerical Integration is the: |
| 00:58 | Study of how the numerical value of an integral can be found |
| 01:03 | It is used when exact mathematical integration is not available |
| 01:08 | It approximates a definite integral from values of the integrand |
| 01:15 | Let us study Composite Trapezoidal Rule. |
| 01:18 | This rule is the extension of trapezoidal rule |
| 01:22 | We divide the interval a comma b into n equal intervals |
| 01:29 | Then h equal to b minus a divided by n is the common length of the intervals |
| 01:36 | Then composite trapezoidal rule is given by |
| 01:41 | The integral of the function F of x in the interval a to b is approximately equal to h multiplied by the sum of the values of the function at x zero to x n |
| 01:57 | Let us solve an example using composite trapezoidal rule. |
| 02:02 | Assume the number of intervals n is equal to ten. |
| 02:09 | Let us look at the code for Composite Trapezoidal Rule on Scilab Editor |
| 02:16 | We first define the function with parameters f , a , b , n. |
| 02:22 | f refers to the function we have to solve, |
| 02:25 | a is the lower limit of the integral, |
| 02:28 | b is the upper limit of the integral and |
| 02:31 | n is the number of intervals. |
| 02:34 | linspace function is used to create ten equal intervals between zero and one |
| 02:42 | We find the value of the integral and store it in I one |
| 02:49 | Click on Execute on Scilab editor and choose Save and Execute the code. |
| 03:02 | Define the example function by typing: |
| 03:05 | d e f f open paranthesis open single quote open square bracket y close square bracket is equal to f of x close quote comma open quote y is equal to one by open paranthesis two asterisk x plus one close paranthesis close quote close paranthesis |
| 03:30 | Press Enter |
| 03:31 | Type Trap underscore composite open paranthesis f comma zero comma one comma ten close paranthesis
|
| 03:41 | Press Enter |
| 03:43 | The answer is displayed on the console |
| 03:47 | Next we shall study Composite simpson's rule. |
| 03:51 | In this rule, we decompose the interval a comma b into n is greater than 1 subintervals of equal length |
| 04:03 | Apply Simpson's rule to each interval |
| 04:06 | We get the value of the integral to be |
| 04:10 | h by three multiplied by the sum of f zero, four into f one , two into f two to f n |
| 04:19 | Let us solve an example using Composite Simpson's rule. |
| 04:24 | We are given a function one by one plus x cube d x in the interval one to two |
| 04:32 | Let the number of intervals be twenty |
| 04:37 | Let us look at the code for Composite simpson's rule |
| 04:42 | We first define the function with parameters f , a , b , n. |
| 04:49 | f refers to the function we have to solve, |
| 04:52 | a is the lower limit of the integral, |
| 04:56 | b is the upper limit of the integral and |
| 04:58 | n is the number of intervals. |
| 05:02 | We find two sets of points. |
| 05:04 | We find the value of the function with one set and multiply it with two |
| 05:10 | With the other set, we find the value and multiply it with four |
| 05:16 | We sum these values and multiply it with h by three and store the final value in I |
| 05:24 | Let us execute the code |
| 05:28 | Save and execute the file Simp underscore composite dot s c i |
| 05:39 | Let me clear the screen first. |
| 05:42 | Define the function given in the example by typing |
| 05:45 | d e f f open paranthesis open single quote open square bracket y close square bracket is equal to f of x close quote comma open quote y is equal to one divided by open paranthesis one plus x cube close paranthesis close quote close paranthesis |
| 06:12 | Press Enter |
| 06:14 | Type Simp underscore composite open paranthesis f comma one comma two comma twenty close paranthesis |
| 06:24 | Press Enter |
| 06:26 | The answer is displayed on the console. |
| 06:31 | Let us now look at Composite Midpoint Rule. |
| 06:35 | It integrates polynomials of degree one or less |
| 06:40 | Divides the interval a comma b into a subintervalsof equal width |
| 06:49 | Finds the midpoint of each interval indicated by x i |
| 06:54 | We find the sum of the values of the integral at each midpoint |
| 07:00 | Let us solve this problem using Composite Midpoint Rule |
| 07:05 | We are given a function one minus x square d x in the interval zero to one point five |
| 07:15 | We assume n is equal to twenty |
| 07:18 | Let us look at the code for Composite Midpoint rule |
| 07:24 | We first define the function with parameters f , a , b , n. |
| 07:30 | f refers to the function we have to solve, |
| 07:33 | a is the lower limit of the integral, |
| 07:36 | b is the upper limit of the integral and |
| 07:39 | n is the number of intervals. |
| 07:41 | We find the midpoint of each interval
|
| 07:45 | Find the value of integral at each midpoint and then find the sum and store it in I. |
| 07:53 | Let us now solve the example |
| 07:55 | Save and execute the file mid underscore composite dot s c i |
| 08:04 | Let me clear the screen |
| 08:08 | We define the function given in the example by typing |
| 08:13 | d e f f open paranthesis open single quote open square bracket y close square bracket is equal to f of x close quote comma open quote y is equal to one minus x square close quote close paranthesis |
| 08:37 | Press Enter |
| 08:39 | Then type mid underscore composite open paranthesis f comma zero comma one point five comma twenty close paranthesis |
| 08:53 | Press Enter |
| 08:54 | The answer is displayed on the console |
| 08:59 | Let us summarize this tutorial. |
| 09:02 | In this tutorial we have learnt to: |
| 09:04 | Develop Scilab code for numerical integration |
| 09:08 | Find the value of an integral
|
| 09:11 | Watch the video available at the link shown below |
| 09:15 | It summarises the Spoken Tutorial project |
| 09:18 | If you do not have good bandwidth, you can download and watch it |
| 09:23 | The spoken tutorial Team |
| 09:25 | Conducts workshops using spoken tutorials |
| 09:29 | Gives certificates to those who pass an online test |
| 09:32 | For more details, please write to contact@spoken-tutorial.org |
| 09:40 | Spoken Tutorial Project is a part of the Talk to a Teacher project |
| 09:45 | It is supported by the National Mission on Eduction through ICT, MHRD, Government of India. |
| 09:52 | More information on this mission is available at http://spoken-tutorial.org/NMEICT-Intro |
| 10:03 | This is Ashwini Patil signing off. Thank you for joining. |
