Lecture (01) Introduction

Transcription

1 Lecture (01) Introduction By: Dr. Ahmed ElShafee ١ Dr. Ahmed ElShafee, ACU : Spring 2018, HUM107 Introduction to Engineering What Is MATLAB? MATLAB (matrix laboratory) is a multi paradigm numerical computing environment and fourth generation programming language. A proprietary programming language developed by MathWorks, ٢

2 MATLAB allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces, and interfacing with programs written in other languages, including C, C++, C#, Java, Fortran and Python. ٣ History Version Release name Number Year Release date Notes MATLAB MATLAB MATLAB MATLAB Ran on DOS but needed at least a 386 processor; version 3.5m needed math coprocessor MATLAB Ran on Macintosh MATLAB 4.2c 1994 Ran on Windows 3.1x, needed a math coprocessor ٤ MATLAB 9.0 R2016a March 3, 2016 MATLAB 9.1 R2016b September 15, 2016 Matlab 9.2 R August 2017

3 To download mat lab 2016a Password: 2016a Winrar program rar.com/start.html?&l=0 ٥ How To Understand Satellites In Its Orbit ٦

4 ٧ ٨

5 ٩ Mph=Miles per hour ١٠

6 ١١ ١٢

7 ١٣ ١٤

8 ١٥ ١٦

9 ١٧ ١٨

10 ١٩ ٢٠

11 ٢١ ٢٢

12 ٢٣ ٢٤

13 ٢٥ ٢٦

14 ٢٧ ٢٨

15 ٢٩ Image processing L1P1 ٣٠

16 ٣١ L1P2 ٣٢

17 L1P3 ٣٣ ٣٤

18 ٣٥ L1P4 ٣٦

19 ٣٧ L1P5 ٣٨

20 ٣٩ L1P6 ٤٠

21 ٤١ L1P7 redchannel = a(:, :, 1); greenchannel = a(:, :, 2); bluechannel = a(:, :, 3); subplot(2, 2, 1); image(a); subplot(2, 2, 2); image(redchannel); subplot(2, 2, 3); image(greenchannel); subplot(2, 2, 4); image(bluechannel); ٤٢

22 ٤٣ mask = redchannel > 160 & greenchannel > 150 & bluechannel > 100; maskedred = redchannel; maskedgreen = greenchannel; maskedblue = bluechannel; coloredimage = cat(3, maskedred, maskedblue,maskedgreen ); imshow(coloredimage); ٤٤

23 ٤٥ coloredimage = cat(3,maskedblue, maskedred,maskedgreen ); imshow(coloredimage); ٤٦

24 ٤٧ coloredimage = cat(3,maskedgreen, maskedred,maskedblue ); imshow(coloredimage); ٤٨

25 ٤٩ make a music >> L1P8 >> L1P9 ٥٠

26 a = sin(2*pi*220*(0: :0.5)); sound(a); b = sin(2*pi*246.94*(0: :0.5)); sound(b); c = sin(2*pi*261.62*(0: :0.5)); sound(c); d = sin(2*pi*293.66*(0: :0.5)); sound(d); e = sin(2*pi*329.62*(0: :0.5)); sound(e); f = sin(2*pi*349.22*(0: :0.5)); sound(f); g = sin(2*pi*391.99*(0: :0.5)); sound(g); ٥١ line1 = [a,b,c,d,e,f]; line2 = [a,b,c,d,e,f]; sound(line1); sound(line2); ٥٢

27 L1P10 L1P11 song = [C CG GA AG F FE ED DC G GF FE ED G GF FE ED C CG GA AG F FE ED D C]; sound(song); ٥٣ ٥٤

28 Work with sound files [y,fs]=soundread('d:\matlab\sound01.wav'); soundsc(y,fs); plot(y); L1P12 L1P13 ٥٥ ٥٦

29 N = size(y,1); figure; subplot(2,1,1); stem(1:n, y(:,1)); title('left Channel'); subplot(2,1,2); stem(1:n, y(:,2)); title('right Channel'); ٥٧ ٥٨

30 [y1,fs]=audioread('d:\matlab\sound01.wav'); df = fs / N; w = ( (N/2):(N/2) 1)*df; z = fft(y1(:,1), N) / N; z2 = fftshift(z); L1P14 figure; plot(w,abs(z2)); axis([ ]) ٥٩ ٦٠

31 [y1,fs]=audioread('d:\matlab\sound01.wav'); df = fs / N; w = ( (N/2):(N/2) 1)*df; z = fft(y1(:,1), N) / N; z2 = fftshift(z); plot(w,abs(z2)); axis([ ]) %filter L1P15 n = 7; beginfreq =200 / (fs/2); endfreq = / (fs/2); [b,a] = butter(n, [beginfreq, endfreq], 'bandpass'); y2 = filter(b, a, y1); df = fs / N; w = ( (N/2):(N/2) 1)*df; z = fft(y2(:,1), N) / N; z2 = fftshift(z); hold; plot(w,abs(z2)); ٦١ axis([ ]) %soundsc(y2(90000:200000,:),fs); % soundsc(y1(90000:200000,:),fs); L1P16 ٦٢

32 ٦٣ MATLAB Interactive Session To start MATLAB on a MS Windows system, doubleclick on the MATLAB icon. You will then see the MATLAB ٦٤ Desktop

33 You can manipulate other windows in the same way. To restore the default configuration, click on the Desktop menu, then click on Desktop Layout, and select ٦٥ Default. Work with matlab as simple calculator ٦٦

34 Exploring (return up arrow down arrow left arrow right arrow) ٦٧ Note that the variable ans now has the value 4. You can use variables to write mathematical expressions. Instead of using the default variable ans, you can assign the result to a variable of your own choosing, say, r, ٦٨

35 Note: you can put a space before and after the = sign if you want. MATLAB ignores these spaces when making its calculations. It also ignores spaces surrounding % and! signs. ٦٩ Calling and reusing variables: ٧٠

36 MATLAB has hundreds of functions available. One of these is the square root function, sqrt ٧١ Getting help ٧٢

37 ٧٣ Scalar arithmetic operations ٧٤

38 Note : consider the difference between left and right division ٧٥ Order of precedence ٧٦

39 ٧٧ Example 01 ٧٨

40 ٧٩ ٨٠

41 The Assignment Operator The = sign in MATLAB is called the assignment or replacement operator When you type x = 3, you tell MATLAB to assign the value 3 to the variable x When you type : x = x + 2. This tells MATLAB to add 2 to the current value of x, and to replace the current value of x with this new value. If you type: >>x = 5 + y if the variable y has not been assigned a value, then the following will generate an error message in ٨١ Example 02 The volume of a circular cylinder of height h and radius r is given by V=pi r 2 h. Aparticular cylindrical tank is 15 m tall and has a radius of 8 m. We want to construct another cylindrical tank with a volume 20 percent greater but having the same height. How large must its radius be? ٨٢

42 Example 02 First solve the cylinder equation for the radius r. ٨٣ Thanks,.. ٨٤ Dr. Ahmed ElShafee, ACU : Spring 2018, HUM107 Introduction to Engineering