Scilab/C4/Digital-Signal-Processing/English - Revision history

Gaurav at 09:18, 20 May 2015

2015-05-20T09:18:50Z

Show changes

Nancyvarkey at 00:52, 19 May 2015

2015-05-19T00:52:24Z

Lavitha Pereira: Created page with ''''Title of script''': '''Signal processing Using Scilab''' '''Author: Manas''' '''Keywords: Video tutorial, Signal''' {| style="border-spacing:0;" ! Visual Cue
2013-06-13T05:45:38Z

Created page with ''''Title of script''': '''Signal processing Using Scilab''' '''Author: Manas''' '''Keywords: Video tutorial, Signal''' {| style="border-spacing:0;" ! <center>Visual Cue</cen…'

New page
'''Title of script''': '''Signal processing Using Scilab'''

'''Author: Manas'''

'''Keywords: Video tutorial, Signal'''

{| style="border-spacing:0;"
! <center>Visual Cue</center>
! <center>Narration</center>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Dear Friends,

Welcome to the spoken tutorial on “'''Signal Processing using Scilab'''”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 2 -Learning Objective Slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial, using Scilab, I will show you how to

Generate different kinds of signals , and

Perform different operations to analyse signals.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3-System Requirement slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| To record this tutorial, I am using '''Ubuntu 11.04''' as the operating system with '''Scilab 5.3.3''' version

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4- Prerequisite slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Before practicing this tutorial, a learner should have a basic knowledge of Scilab. To know the basics of Scilab,

please refer to the series of Basic level of spoken tutorials in Scilab

which is available on our website www.spoken-tutorial.org

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial, I will describe about 3 basic Signals.

* Plotting continuous and discrete sine wave.
* Plotting step function.
* Plotting ramp function.

Let me start with “Plotting continuous and discrete sine wave”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the Scilab Console Window and type:

'''t <nowiki>=</nowiki> 0:0.1:2%pi;'''

'''x <nowiki>=</nowiki> sin(t);'''

'''plot2d(t,x)'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us switch to the Scilab Console Window.

Here type:

'''t equal to zero colon zero point one colon two multiplied by precentage pi semicolon.'''

'''x equal to sin of t semicolon plot 2D into bracket t comma x'''

and press Enter key on your keyboard.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the plot generated
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is a continous sine wave

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| On the console window type:

'''plot2d3('gnn',t,x)'''

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us discuss the discrete sine wave.

On the console window type: plot two d into bracket within invertes comma gnn then comma t comma x and press Enter on your keyboard.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the plot generated
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is discret sine wave.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to Slide 7: and display 2<sup>nd</sup> and 3<sup>rd</sup> point of Slide 7
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us now discuss about Plotting step function and

plotting ramp function.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open scilab editor.

Open the file signal.sce
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I have already written the code to generate step and ramp signal in the file called signals.sce.

Let us open this file signal.sce using scilab editor.

Let us execute this code.

Click on the “Execute” button in the Menu bar

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the plot generated
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Step and Ramp signal is displayed in this plot.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now let us learn how to perform different operations to analyse signals.

Let us see how to perform Convolution between two signals.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Swtich to Scilab console and type: '''<nowiki>x=[1,2</nowiki> ,3,4]'''

'''Then type:'''

'''<nowiki>h=[1,1,1]</nowiki>'''

'''and then type'''

Type:''' convol(x,h) '''and press Enter

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us switch to the Scilab Console window and type

'''x equals to into braccket one comma two comma three comma '''

'''four'''

Then type '''h equals to into bracket one comma one comma one'''

Now let us apply the convoltion by typing''' convol opening bracket x comma h closing bracket'''

and press Enter on your keyboard.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the output generated
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| An output can be seen here.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now let us learn Discrete fourier transform for a discrete sequence by using the inbuilt command dft().

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| On the Scilab console window, type: <nowiki>x=[1,2,3,4]</nowiki>

Type: '''<nowiki>[xf]=dft(x,-1);</nowiki>'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| On the console window here type '''x equals to into braccket one comma two comma three comma four'''

Then

Type''' inside bracket xf equals to dft into bracket x comma minus 1'''

Where x is the input vector

and flag value is -1 for DFT.

Let us press Enter

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the output:

'''10. '''

'''- 2. + 2.i '''

'''- 2. - 9.797D-16i '''

'''- 2. - 2.i '''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output appears as

'''10. '''

'''- 2. + 2.i '''

'''- 2. - 9.797D-16i '''

'''- 2. - 2.i '''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now I will show you how to calculate inverse discrete fourier transform. This can be done by using the same inbuilt command dft().

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| On the Scilab console window:'''<nowiki>[x]=dft(xf,1)</nowiki>'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| On the Scilab console window type:

'''Bracket x equals to dft into bracket xf comma 1'''

Here the flag value is 1 for idft.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the output: '''1. '''

'''2. + 5.551D-17i '''

'''3. - 1.225D-16i '''

'''4. - 5.551D-16i'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is the output.

'''1. '''

'''2. + 5.551D-17i '''

'''3. - 1.225D-16i '''

'''4. - 5.551D-16i'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us calculate discrete fourier transform using fft()

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type: x= <nowiki>[1,2,3,4]</nowiki> and press Enter

Type:'''y <nowiki>=</nowiki> fft(x,-1)'''

Display the output:

'''10. - 2. + 2.i - 2. - 2. - 2.i '''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| On the console window, type '''x= <nowiki>[1,2,3,4]</nowiki> x equals to into braccket one comma two comma three comma four'''

Press Enter and type '''y <nowiki>=</nowiki> fft(x,-1)''' y equals to fft into bracket x comma minus one

Press Enter and you can see the output as

'''10. - 2. + 2.i - 2. - 2. - 2.i '''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| On the Scilab Console window type: '''<nowiki>y=[10,-2+2%i,-2,-2-2*%i]</nowiki>''' and press Enter

Type: '''x <nowiki>=</nowiki> fft(y,1)'''

and Press Enter

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us now see how to calculate inverse discrete fourier transform by using fft().

On the Scilab console window type

y equals to into bracket ten comma minus two plus two into percentage i comma minus two comma minus two plus minus two into percentage i.

and Press Enter

Type '''x <nowiki>=</nowiki> fft(y,1)''' x equals to fft into bracket y comma 1

and Press Enter

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display the output:

'''x <nowiki>=1.</nowiki> 2. 3. 4.'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output will be displayed as

'''x <nowiki>=1.</nowiki> 2. 3. 4.'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us now find out the correlation between two vectors.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the Scilab console window

Type: '''<nowiki>x1=[1,2,3,4]</nowiki> '''and Press Enter

Type: '''<nowiki>x2=[1,3,1,5]</nowiki> '''and press Enter

Type '''Rx1x2 <nowiki>=</nowiki> corr(x1,x2,4)'''

The output will be displayed as

'''Rx1x2=1.25 0.3125 0.25 - 0.9375 '''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| To do this on the Scilab console window,

Type '''x one equals to into braccket one comma two comma three comma four'''and press Enter

Type''' x2 equals to into braccket one comma three comma one comma five '''and press Enter

Type '''Are x one x two equals to corr into bracket x one comma x two comma four '''and press Enter

The output will be displayed as

'''Rx1x2=1.25 0.3125 0.25 - 0.9375'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us learn sampling the given signal

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open sampling.sce

Click on “Execute” button

Display the output.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let me open sampling.sce where

I have already written the code in sampling.sce

Here click on the “'''Execute'''”button.

A plot is displayed.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let me summarise.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 14
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial we learnt

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Summary slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| To Plot sine, step and ramp signal.

To perform Linear convolution by convol().

To perform DFT and IDFT by dft().

To perform FFT by fft().

To find out the Correlation by corr().

To do the sampling

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display “About the Spoken Tutorial Project” Slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Watch the video available at

http://spoken-tutorial.org

/What is a Spoken Tutorial

It summarises the Spoken Tutorial

project

If you do not have good

bandwidth, you can download

and watch it

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display “ Spoken Tutorial Workshops” slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The Spoken Tutorial Project Team

Conducts workshops using spoken

tutorials

Gives certificates to those who

pass an online test

For more details, contact

contact@spoken-tutorial.org

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display “Acknowledgment”

slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Spoken Tutorial Project is a part

of the Talk to a Teacher project

It is supported by the National

Mission on Education through

ICT, MHRD, Government of India

More information on the same is

available at:

http://spoken-tutorial.org

/NMEICT-Intro

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Disaplay “Contributors” slide
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This script has been contributed

by Manas and this is Anuradha

signing off

Thank you for watching

|}