EGR106 Week 5

1. EGR106 Week 5 • MATLAB FILES • Two Dimensional Plots • Multiple Plots • Plot Formatting • Homework

2. MATLAB Files • Script files (m files) • Text files • Contain MATLAB commands • Data Files (mat files) • binary files • Contain arrays (data) • Use “save” and “load” commands to write and read

3. Two Dimensional Plots • Line type • plot(x,y,’--’) gives a dashed line • Line color • plot(x,y,’g’) gives a green line • Line thickness • Markers • plot(x,y,’--r*’,’linewidth’,2,’markersize’,12) • Dashed red line with * marker

4. Multiple Plots • Plot(x, y1, x, y2) Plots y1 and y2 vs x • hold on • Keeps the plot window open for additional lines on the same plot • hold off • Stops writing to the plot • subplot(n,m,k) • Selects plot k in an nxm array of plots. • Used for multiple plots on the same page.

5. Plot Formatting • xlabel, ylabel • xlabel(‘time (sec)’) • title • title(‘Problem 3 Solution’) • text • text(x,y,’your message at coordinates x,y’) • legend • legend(‘first curve’,’second curve’) • used for multiple curves on a single plot

6. Plot Formatting • Subscripts and superscripts • Greek letters • Rotating text

7. >> x=0:2:10; >> y=x.^2; >> plot(x,y,'--r*','linewidth',2,'markersize',12) >> text(2,50,'\fontsize{30} \alpha Profit= x^2 ', 'rotation',45)

8. sound_in sound=data; % Note that data is a one column array with 8000 rows. echo(4001:12000,1)=sound; % The echo is the sound delayed 4000 units (4000/8000 sec) % Writing into rows 4001:12000 automatically % sets rows 1:4000 equal to zero. sound(8001:12000,1)=0; % Pad the end of the sound with zeros so echo and % sound are the same size. data= sound + 0.25*echo; % Attenuate the echo to 25% of the sound % and add it to the original sound. pause(2) % Wait 2 seconds to hear the sound plus the echo. sound_out

9. Array Addressing Store Audio number(:,1) = zero ; % store zero in column 1 number(:,2) = one; % additional digits are stored number(:,3) = two; % in column number + 1. Get User Number no = input('What is the first digit? ') data = number(:,no+1); % Read audio from memory no = input('What is the next digit? ') data = [data ; number(:,no+1)]; % build data array sound_out