Difference between revisions of "Scilab/C4/ODE-Euler-methods/English-timed"

From Script | Spoken-Tutorial
Jump to: navigation, search
(Created page with '{| Border=1 || Time || Narration |- | 00.01 |Dear Friends, |- | 00.02 | Welcome to the Spoken Tutorial on '''“Solving ODEs using Euler Methods” ''' |- | 00.09 | At the …')
 
 
(4 intermediate revisions by 2 users not shown)
Line 1: Line 1:
 
{| Border=1
 
{| Border=1
  
|| Time
+
|'''Time'''
 
+
|'''Narration'''
|| Narration
+
  
 
|-
 
|-
| 00.01
+
| 00:01
|Dear Friends,  
+
|Dear Friends, Welcome to the Spoken Tutorial on '''Solving ODEs using Euler Methods'''.
  
 
|-
 
|-
| 00.02
+
| 00:09
| Welcome to the Spoken Tutorial on '''“Solving ODEs using Euler Methods” '''
+
 
+
|-
+
| 00.09
+
 
| At the end of this tutorial, you will learn how to:   
 
| At the end of this tutorial, you will learn how to:   
  
 
|-
 
|-
|00.12
+
|00:12
 
|Solve '''ODEs''' using '''Euler''' and '''Modified Euler methods''' in '''Scilab'''
 
|Solve '''ODEs''' using '''Euler''' and '''Modified Euler methods''' in '''Scilab'''
  
 
|-
 
|-
|00.18
+
|00:18
|Develop '''Scilab''' code to solve '''ODEs'''
+
|Develop '''Scilab''' code to solve '''ODEs'''.
  
 
|-
 
|-
| 00.22
+
| 00:22
 
|To record this tutorial, I am using  
 
|To record this tutorial, I am using  
  
 
|-
 
|-
|00.25
+
|00:25
 
|'''Ubuntu 12.04''' as the operating system  
 
|'''Ubuntu 12.04''' as the operating system  
 
  
 
|-
 
|-
| 00.28
+
| 00:28
|and '''Scilab 5.3.3''' version  
+
|and '''Scilab 5.3.3''' version.
  
 
|-
 
|-
| 00.32
+
| 00:32
| To practise this tutorial, a learner  
+
| To practice this tutorial, a learner  
  
 
|-
 
|-
|00.34
+
|00:34
 
|should have basic knowledge of '''Scilab'''  
 
|should have basic knowledge of '''Scilab'''  
  
 
|-
 
|-
|00.37
+
|00:37
 
|and should know how to solve '''ODEs.'''
 
|and should know how to solve '''ODEs.'''
  
 
|-
 
|-
| 00.40
+
| 00:40
 
| To learn '''Scilab,''' please refer to the relevant tutorials available on the '''Spoken Tutorial''' website.  
 
| To learn '''Scilab,''' please refer to the relevant tutorials available on the '''Spoken Tutorial''' website.  
  
 
|-
 
|-
| 00.48
+
| 00:48
 
| In '''Euler method,''' we get an accurately approximate solution of the '''ODE.'''  
 
| In '''Euler method,''' we get an accurately approximate solution of the '''ODE.'''  
  
 
|-
 
|-
|00.55
+
|00:55
 
|It is used to solve initial value problems where initial values of the '''differential equation''' are given.  
 
|It is used to solve initial value problems where initial values of the '''differential equation''' are given.  
  
 
|-
 
|-
|01.03
+
|01:03
 
| It can be used to solve '''continuous functions.'''  
 
| It can be used to solve '''continuous functions.'''  
  
 
|-
 
|-
 
+
|01:08
|01.08
+
 
+
 
|Let us solve an example using '''Euler method.'''
 
|Let us solve an example using '''Euler method.'''
  
 
|-
 
|-
 
+
|01:12
|01.12
+
 
|We are given an initial value problem -  
 
|We are given an initial value problem -  
  
 
|-
 
|-
 
+
| 01:15
| 01.15
+
 
+
 
|'''y dash is equal to minus two t minus y.'''  
 
|'''y dash is equal to minus two t minus y.'''  
 
  
 
|-
 
|-
 
+
| 01:20
| 01.20
+
||The initial value of y is given as '''minus one'''(-1)
||The initial value of y is given as '''minus one'''  
+
  
 
|-
 
|-
 
+
|01:25
|01.25
+
|| and the '''step length''' is given as '''zero point one'''(0.1).
 
+
|| and the '''step length''' is given as '''zero point one.'''  
+
 
+
  
 
|-
 
|-
 
+
|01:29
|01.29
+
 
+
 
| We have to find the value of '''y''' at time '''t equal to zero point five.'''  
 
| We have to find the value of '''y''' at time '''t equal to zero point five.'''  
  
 
|-
 
|-
|01.36
+
|01:36
 
|Let us look at the code for '''Euler method.'''  
 
|Let us look at the code for '''Euler method.'''  
 
 
   
 
   
 
|-
 
|-
 
+
|01:39
|01.39
+
 
+
 
|Open '''Euler underscore o d e dot sci''' on '''Scilab editor.'''  
 
|Open '''Euler underscore o d e dot sci''' on '''Scilab editor.'''  
  
 
|-
 
|-
 
+
|01:47
|01.47
+
||We define the function '''Euler underscore o d e''' with arguments '''f, t init, y init, h''' and '''N'''
 
+
 
+
||We define the function '''Euler underscore o d e with arguments f, t init, y init, h and n'''
+
 
+
  
 
|-
 
|-
|01.58
+
|01:58
|'where '''f''' denotes the function to be solved,  
+
|'where: '''f''' denotes the function to be solved,  
 
+
  
 
|-
 
|-
 
+
| 02:01
| 02.01
+
 
|'''t init''' is the initial value of time '''t''',  
 
|'''t init''' is the initial value of time '''t''',  
  
 
|-
 
|-
 
+
|02:05
|02.05
+
||'''y init'''  is the initial value of '''y''',
 
+
||'''y init'''  is the initial value of '''y'''
+
 
|-
 
|-
 
+
|02:09
|02.09
+
| '''h''' is the '''step length''' and '''n''' is the number of '''iterations.'''  
 
+
| '''h''' is the '''step length,''' and '''n''' is the number of '''iterations.'''  
+
  
 
|-
 
|-
 
+
|02:14
|02.14
+
| Then we initialize the values of '''t''' and '''y''' to vectors of '''zeros.'''
 
+
| Then we initialize the values of '''t''' and '''y to vectors of zeros. '''
+
 
|-
 
|-
 
+
| 02:21
| 02.21
+
 
+
 
|| We place the initial values of '''t''' and '''y''' in '''t of one''' and '''y of one''' respectively.  
 
|| We place the initial values of '''t''' and '''y''' in '''t of one''' and '''y of one''' respectively.  
  
 
|-
 
|-
| 02.29
+
| 02:29
 
| Then we '''iterate''' from '''one to N''' to find the value of '''y'''.  
 
| Then we '''iterate''' from '''one to N''' to find the value of '''y'''.  
  
 
|-
 
|-
|02.33
+
|02:33
 
| Here we apply '''Euler method''' to find the value of '''y. '''  
 
| Here we apply '''Euler method''' to find the value of '''y. '''  
  
 
|-
 
|-
|02.39
+
|02:39
| Finally we end the '''function. '''
+
| Finally we '''end''' the '''function.'''
  
 
|-
 
|-
| 02.42
+
| 02:42
|Save and execute the file '''Euler underscore o d e dot sci'''
+
|'''Save and execute''' the file '''Euler underscore o d e dot sci'''.
+
  
 
|-
 
|-
| 02.49
+
| 02:49
 
|Switch to '''Scilab console''' to solve the example problem.  
 
|Switch to '''Scilab console''' to solve the example problem.  
 
 
  
 
|-
 
|-
| 02.54
+
| 02:54
 
|We define the ''' function ''' by typing  
 
|We define the ''' function ''' by typing  
 
  
 
|-
 
|-
| 02.56
+
| 02:56
|'''d e f f open paranthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to open paranthesis minus two asterisk t close paranthesis minus y close single quote close paranthesis '''
+
|'''d e f f open parenthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to open parenthesis minus two asterisk t close parenthesis minus y close single quote close parenthesis '''
 
+
  
 
|-
 
|-
|03.26
+
|03:26
 
|Press '''Enter. '''
 
|Press '''Enter. '''
  
 
|-
 
|-
|03.28
+
|03:28
| Then type '''t init is equal to zero. '''
+
| Then type: '''t init is equal to zero. '''
 
+
  
 
|-
 
|-
 
+
| 03:31
| 03.31
+
|Press '''Enter.'''
 
+
|Press '''Enter. '''
+
 
+
 
+
 
+
  
 
|-
 
|-
 
+
| 03:33
| 03.33
+
||Type: '''y init is equal to minus one.'''
||Type '''y init is equal to minus one. '''
+
'
+
 
+
  
 
|-
 
|-
 
+
|03:38
|03.38
+
||Press '''Enter '''.
 
+
||Press '''Enter '''
+
 
+
  
 
|-
 
|-
 
+
| 03:40
| 03.40
+
| Type: '''step length h is equal to zero point one.'''
| Type '''step length h is equal to zero point one. '''
+
 
+
 
+
  
 
|-
 
|-
 
+
| 03:44
| 03.44
+
| Press '''Enter'''.
 
+
| Press '''Enter'''
+
 
+
  
 
|-
 
|-
 
+
| 03:46
| 03.46
+
| The '''step length''' is zero point one and we have to find the value of '''y''' at '''zero point five.'''
 
+
| The '''step length is zero point one,''' and we have to find the value of '''y''' at '''zero point five.'''
+
 
+
  
 
|-
 
|-
 
+
|03:53
|03.53
+
 
+
 
||So, the number of '''iterations''' should be '''five.'''  
 
||So, the number of '''iterations''' should be '''five.'''  
 
  
 
|-
 
|-
 
+
|03:59
|03.59
+
 
+
 
|At each '''iteration,'''  the value of '''t''' will be increased by '''zero point one.'''  
 
|At each '''iteration,'''  the value of '''t''' will be increased by '''zero point one.'''  
 
  
 
|-
 
|-
 
+
| 04:05
| 04.05
+
| So type capital '''N is equal to five''' (N=5)
 
+
| So type '''capital N is equal to five.'''  
+
 
+
 
+
 
+
  
 
|-
 
|-
 
+
| 04:09
| 04.09
+
|and press '''Enter.'''
 
+
|And press '''Enter.'''
+
 
+
  
 
|-
 
|-
 
+
| 04:11
| 04.11
+
| To '''call''' the '''function,''' type:
 
+
| To '''call''' the '''function,''' type  
+
  
 
|-
 
|-
 
+
| 04:14
| 04.14
+
| '''open square bracket t comma y close square bracket equal to Euler underscore o d e open parenthesis f comma t init comma y init comma h comma capital N close parenthesis '''
 
+
| '''open square bracket t comma y close square bracket equal to Euler underscore o d e open paranthesis f comma t init comma y init comma h comma capital N close paranthesis '''
+
  
 
|-
 
|-
 
+
| 04:33
| 04.33
+
 
+
 
||Press '''Enter.'''  
 
||Press '''Enter.'''  
 
  
 
|-
 
|-
 
+
| 04:35
| 04.35
+
 
+
 
||The value of '''y at t equal to zero point five''' is shown.  
 
||The value of '''y at t equal to zero point five''' is shown.  
  
 
|-
 
|-
 
+
| 04:41
| 04.41
+
 
+
 
||Now let us look at '''Modified Euler method. '''
 
||Now let us look at '''Modified Euler method. '''
  
 
|-
 
|-
 
+
| 04:45
| 04.45
+
 
+
 
|It is a '''second order method''' and is a '''stable two step method. '''
 
|It is a '''second order method''' and is a '''stable two step method. '''
 
  
 
|-
 
|-
 
+
| 04:51
| 04.51
+
 
+
 
|We find the '''average''' of the '''function''' at the beginning and end of '''time step.'''  
 
|We find the '''average''' of the '''function''' at the beginning and end of '''time step.'''  
 
  
 
|-
 
|-
 
+
|04:56
|04.56
+
 
+
 
|Let us solve this example using '''Modified Euler method.'''  
 
|Let us solve this example using '''Modified Euler method.'''  
 
 
  
 
|-
 
|-
 
+
| 05:02
| 05.02
+
 
+
 
|We are given a '''function y dash is equal to t plus y plus t y. '''
 
|We are given a '''function y dash is equal to t plus y plus t y. '''
 
 
 
  
 
|-
 
|-
 
+
| 05:08
| 05.08
+
 
+
 
| The initial value of '''y''' is '''one'''  
 
| The initial value of '''y''' is '''one'''  
  
 
|-
 
|-
 
+
| 05:12
| 05.12
+
 
+
 
| and the '''step length''' is '''zero point zero one.'''  
 
| and the '''step length''' is '''zero point zero one.'''  
  
 
|-
 
|-
 
+
| 05:16
| 05.16
+
 
+
 
|We have to find the value of '''y'''  at '''time t equal to zero point one ''' using '''Modified Euler's method.'''  
 
|We have to find the value of '''y'''  at '''time t equal to zero point one ''' using '''Modified Euler's method.'''  
 
 
  
 
|-
 
|-
| 05.25
+
| 05:25
| Let us look at the code for '''Modified Euler method on Scilab Editor'''
+
| Let us look at the code for '''Modified Euler method''' on '''Scilab Editor'''.
  
 
|-
 
|-
| 05.31
+
| 05:31
|We define the '''function''' with '''arguments f, t init, y init, h and n'''  
+
|We define the '''function''' with '''arguments f, t init, y init, h''' and '''n'''  
 
|-
 
|-
 
+
| 05:39
| 05.39
+
| where: '''f''' is the '''function''' to be solved,
 
+
| '''where f''' is the '''function''' to be solved
+
 
+
  
 
|-
 
|-
 
+
| 05:42
| 05.42
+
 
+
 
| '''t init''' is the intial '''time''' value,  
 
| '''t init''' is the intial '''time''' value,  
  
 
|-
 
|-
 
+
| 05:45
| 05.45
+
| '''y init''' is the inital value of  '''y''',
 
+
| '''y init''' is the inital value of  '''y'''
+
  
 
|-
 
|-
 
+
| 05:49
| 05.49
+
 
+
 
| '''h''' is the '''step length''' and  
 
| '''h''' is the '''step length''' and  
 
 
  
 
|-
 
|-
 
+
| 05:51
| 05.51
+
| '''N''' is the number of '''iterations.'''  
 
+
| '''n''' is the number of '''iterations.'''  
+
  
 
|-
 
|-
 
+
| 05:54
| 05.54
+
 
+
 
| Then we initialize the '''arrays''' for '''y''' and '''t.'''
 
| Then we initialize the '''arrays''' for '''y''' and '''t.'''
 
|-
 
|-
 
+
| 05:58
| 05.58
+
 
+
 
|We place the initial values of '''t''' and '''y''' in '''t of one''' and '''y of one''' respectively.  
 
|We place the initial values of '''t''' and '''y''' in '''t of one''' and '''y of one''' respectively.  
  
 
|-
 
|-
 
+
| 06:07
| 06.07
+
 
+
 
|We implement '''Modified Euler Method''' here.  
 
|We implement '''Modified Euler Method''' here.  
 
  
 
|-
 
|-
 
+
| 06:11
| 06.11
+
 
+
 
|Here we find the average value of '''y''' at the beginning and end of '''time step.'''  
 
|Here we find the average value of '''y''' at the beginning and end of '''time step.'''  
  
 
|-
 
|-
 
+
| 06:17
| 06.17
+
|'''Save and execute''' the file '''Modi Euler underscore o d e dot sci.'''  
 
+
|Save and execute the file '''Modi Euler underscore o d e dot sci.'''  
+
 
|-
 
|-
 
+
| 06:23
| 06.23
+
 
+
 
|Switch to '''Scilab console.'''
 
|Switch to '''Scilab console.'''
  
 
|-
 
|-
 
+
| 06:26
| 06.26
+
 
+
 
|Clear the screen by typing '''c l c.'''  
 
|Clear the screen by typing '''c l c.'''  
 
|-
 
|-
 
+
| 06:30
| 06.30
+
 
+
 
|Press '''Enter.'''  
 
|Press '''Enter.'''  
 
  
 
|-
 
|-
 
+
| 06:32
| 06.32
+
|Define the '''function''' by typing '''d e f f open parenthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to t plus y plus t asterisk y close single quote close parenthesis'''  
|Define the '''function''' by typing '''d e f f open paranthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to t plus y plus t asterisk y close single quote close paranthesis'''  
+
  
 
|-
 
|-
 
+
| 07:01
| 07.01
+
 
+
 
|Press '''Enter.'''
 
|Press '''Enter.'''
 
  
 
|-
 
|-
 
+
| 07:03
| 07.03
+
|Then type: '''t init equal to zero''',  press Enter.
 
+
|Then type '''t init equal to zero''',  press Enter  
+
 
+
  
 
|-
 
|-
 
+
| 07:08
| 07.08
+
|Type: '''y init equal to one''' and press '''Enter.'''  
 
+
|Type '''y init equal to one''' and press '''Enter.'''  
+
 
+
  
 
|-
 
|-
 
+
| 07:12
| 07.12
+
|Then type: '''h equal to zero point zero one''' press '''Enter.'''  
 
+
|Then type '''h equal to zero point zero one''' press '''Enter.'''  
+
  
 
|-
 
|-
 
+
| 07:19
| 07.19
+
|Type: capital '''N equal to ten'''  
 
+
|Type '''capital N equal to ten.'''  
+
 
+
  
 
|-
 
|-
 
+
| 07:22
| 07.22
+
|since the number of '''iterations''' should be '''ten''' to '''time t equal to zero point one''' with '''step length''' of '''zero point zero one.'''
 
+
|Since the number of '''iterations should be ten to time t equal to zero point one with step length of zero point zero one. '''
+
  
 
|-
 
|-
 
+
| 07:34
| 07.34
+
 
+
 
|Press '''Enter.'''
 
|Press '''Enter.'''
  
 
|-
 
|-
 
+
| 07:36
| 07.36
+
|Then call the '''function Modi Euler underscore o d e''' by typing:
 
+
|Then call the '''function modi euler underscore o d e''' by typing.'''
+
  
 
|-
 
|-
 
+
| 07:41
| 07.41
+
|'''open square bracket t comma y close square bracket equal to Modi Euler underscore o d e open parenthesis f comma t init comma y init comma h comma capital N close parenthesis'''  
 
+
|'''open square bracket t comma y close square bracket equal to modi euler underscore o d e open paranthesis f comma t init comma y init comma h comma capital N close paranthesis'''  
+
 
+
  
 
|-
 
|-
 
+
| 08:03
| 08.03
+
 
+
 
|Press '''Enter. '''
 
|Press '''Enter. '''
 
  
 
|-
 
|-
 
+
| 08:05
| 08.05
+
 
+
 
|The value of '''y at t equal to zero point one''' is shown.  
 
|The value of '''y at t equal to zero point one''' is shown.  
  
 
|-
 
|-
 
+
| 08:10
| 08.10
+
 
+
 
|Let us summarize this tutorial.  
 
|Let us summarize this tutorial.  
  
 
|-
 
|-
 
+
| 08:14
| 08.14
+
 
+
 
|In this tutorial we have learnt to develop Scilab code for '''Euler''' and '''modified Euler methods.'''  
 
|In this tutorial we have learnt to develop Scilab code for '''Euler''' and '''modified Euler methods.'''  
  
 
|-
 
|-
 
+
| 08:21
| 08.21
+
 
+
 
|We have also learnt to solve '''ODEs''' using these methods in '''Scilab.'''  
 
|We have also learnt to solve '''ODEs''' using these methods in '''Scilab.'''  
 
 
  
 
|-
 
|-
|08.28
+
|08:28
| Watch the video available at the  link shown below
+
| Watch the video available at the  link shown below.
  
 
|-
 
|-
 
+
| 08:32
| 08.32
+
| It summarizes the Spoken Tutorial project.
 
+
| It summarises the Spoken Tutorial project  
+
 
+
 
+
  
 
|-
 
|-
 
+
|08:35
|08.35
+
||If you do not have good bandwidth, you can download and watch it.
 
+
||If you do not have good bandwidth, you can download and watch it  
+
  
 
|-
 
|-
 
+
|08:40
|08.40
+
||The spoken tutorial project Team:
 
+
||The spoken tutorial project Team
+
  
 
|-
 
|-
 
+
|08:42
|08.42
+
||Conducts workshops using spoken tutorials.
 
+
||Conducts workshops using spoken tutorials  
+
 
+
  
 
|-
 
|-
 
+
|08:45
|08.45
+
||Gives certificates to those who pass an online test.
 
+
||Gives certificates to those who pass an online test  
+
 
+
  
 
|-
 
|-
 
+
|08:49
|08.49
+
||For more details, please write to contact@spoken-tutorial.org.
 
+
||For more details, please write to contact@spoken-tutorial.org  
+
 
+
  
 
|-
 
|-
 
+
|08:55
|08.55
+
|Spoken Tutorial Project is a part of the Talk to a Teacher project.
 
+
|Spoken Tutorial Project is a part of the Talk to a Teacher project  
+
 
+
 
+
  
 
|-
 
|-
 
+
| 09:00
| 09.00
+
 
+
 
| It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.  
 
| It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.  
 
|-
 
|-
 
+
| 09:07
| 09.07
+
|More information on this mission is available at the link shown below.
 
+
|More information on this mission is available at the link shown below
+
  
 
|-
 
|-
 
+
| 09:13
| 09.13
+
|This is Ashwini Patil, signing off.
 
+
|This is Ashwini Patil signing off.
+
  
 
|-
 
|-
 
+
|09:15
|09.15
+
 
+
 
| Thank you for joining.
 
| Thank you for joining.

Latest revision as of 11:16, 10 March 2017

Time Narration
00:01 Dear Friends, Welcome to the Spoken Tutorial on Solving ODEs using Euler Methods.
00:09 At the end of this tutorial, you will learn how to:
00:12 Solve ODEs using Euler and Modified Euler methods in Scilab
00:18 Develop Scilab code to solve ODEs.
00:22 To record this tutorial, I am using
00:25 Ubuntu 12.04 as the operating system
00:28 and Scilab 5.3.3 version.
00:32 To practice this tutorial, a learner
00:34 should have basic knowledge of Scilab
00:37 and should know how to solve ODEs.
00:40 To learn Scilab, please refer to the relevant tutorials available on the Spoken Tutorial website.
00:48 In Euler method, we get an accurately approximate solution of the ODE.
00:55 It is used to solve initial value problems where initial values of the differential equation are given.
01:03 It can be used to solve continuous functions.
01:08 Let us solve an example using Euler method.
01:12 We are given an initial value problem -
01:15 y dash is equal to minus two t minus y.
01:20 The initial value of y is given as minus one(-1)
01:25 and the step length is given as zero point one(0.1).
01:29 We have to find the value of y at time t equal to zero point five.
01:36 Let us look at the code for Euler method.
01:39 Open Euler underscore o d e dot sci on Scilab editor.
01:47 We define the function Euler underscore o d e with arguments f, t init, y init, h and N
01:58 'where: f denotes the function to be solved,
02:01 t init is the initial value of time t,
02:05 y init is the initial value of y,
02:09 h is the step length and n is the number of iterations.
02:14 Then we initialize the values of t and y to vectors of zeros.
02:21 We place the initial values of t and y in t of one and y of one respectively.
02:29 Then we iterate from one to N to find the value of y.
02:33 Here we apply Euler method to find the value of y.
02:39 Finally we end the function.
02:42 Save and execute the file Euler underscore o d e dot sci.
02:49 Switch to Scilab console to solve the example problem.
02:54 We define the function by typing
02:56 d e f f open parenthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to open parenthesis minus two asterisk t close parenthesis minus y close single quote close parenthesis
03:26 Press Enter.
03:28 Then type: t init is equal to zero.
03:31 Press Enter.
03:33 Type: y init is equal to minus one.
03:38 Press Enter .
03:40 Type: step length h is equal to zero point one.
03:44 Press Enter.
03:46 The step length is zero point one and we have to find the value of y at zero point five.
03:53 So, the number of iterations should be five.
03:59 At each iteration, the value of t will be increased by zero point one.
04:05 So type capital N is equal to five (N=5)
04:09 and press Enter.
04:11 To call the function, type:
04:14 open square bracket t comma y close square bracket equal to Euler underscore o d e open parenthesis f comma t init comma y init comma h comma capital N close parenthesis
04:33 Press Enter.
04:35 The value of y at t equal to zero point five is shown.
04:41 Now let us look at Modified Euler method.
04:45 It is a second order method and is a stable two step method.
04:51 We find the average of the function at the beginning and end of time step.
04:56 Let us solve this example using Modified Euler method.
05:02 We are given a function y dash is equal to t plus y plus t y.
05:08 The initial value of y is one
05:12 and the step length is zero point zero one.
05:16 We have to find the value of y at time t equal to zero point one using Modified Euler's method.
05:25 Let us look at the code for Modified Euler method on Scilab Editor.
05:31 We define the function with arguments f, t init, y init, h and n
05:39 where: f is the function to be solved,
05:42 t init is the intial time value,
05:45 y init is the inital value of y,
05:49 h is the step length and
05:51 N is the number of iterations.
05:54 Then we initialize the arrays for y and t.
05:58 We place the initial values of t and y in t of one and y of one respectively.
06:07 We implement Modified Euler Method here.
06:11 Here we find the average value of y at the beginning and end of time step.
06:17 Save and execute the file Modi Euler underscore o d e dot sci.
06:23 Switch to Scilab console.
06:26 Clear the screen by typing c l c.
06:30 Press Enter.
06:32 Define the function by typing d e f f open parenthesis open single quote open square bracket y dot close square bracket equal to f of t comma y close single quote comma open single quote y dot equal to t plus y plus t asterisk y close single quote close parenthesis
07:01 Press Enter.
07:03 Then type: t init equal to zero, press Enter.
07:08 Type: y init equal to one and press Enter.
07:12 Then type: h equal to zero point zero one press Enter.
07:19 Type: capital N equal to ten
07:22 since the number of iterations should be ten to time t equal to zero point one with step length of zero point zero one.
07:34 Press Enter.
07:36 Then call the function Modi Euler underscore o d e by typing:
07:41 open square bracket t comma y close square bracket equal to Modi Euler underscore o d e open parenthesis f comma t init comma y init comma h comma capital N close parenthesis
08:03 Press Enter.
08:05 The value of y at t equal to zero point one is shown.
08:10 Let us summarize this tutorial.
08:14 In this tutorial we have learnt to develop Scilab code for Euler and modified Euler methods.
08:21 We have also learnt to solve ODEs using these methods in Scilab.
08:28 Watch the video available at the link shown below.
08:32 It summarizes the Spoken Tutorial project.
08:35 If you do not have good bandwidth, you can download and watch it.
08:40 The spoken tutorial project Team:
08:42 Conducts workshops using spoken tutorials.
08:45 Gives certificates to those who pass an online test.
08:49 For more details, please write to contact@spoken-tutorial.org.
08:55 Spoken Tutorial Project is a part of the Talk to a Teacher project.
09:00 It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.
09:07 More information on this mission is available at the link shown below.
09:13 This is Ashwini Patil, signing off.
09:15 Thank you for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14