Scilab/C4/Integration/English-timed

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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


06.29 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.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14