Learning Signal and System Using  Matlab (Part _1)

 

 

 Question # 1

 Consider the following equation:

a) Write a MATLAB M-file function to obtain numerical values of y(t). Your function must take  y (0 ),theta, eita , t and   as function inputs and y (t ) as output argument.

b) Obtain the plot for y(t) for 0<t<10 with an increment of 0.1, by considering the following two cases

Case 1:  y( 0)=0.15 m, w= sqrt(2) rad/sec, eita=  3/2sqrt(2) and  theta= 0  ;

Case 2: y( 0)=0.15 m, w= sqrt(2) rad/sec, eita=  1/2sqrt(2) and  theta= 0  ;

Solution:

Open the matlab function file and write the following code Save it with the “sinfunc” name

function y = sinfunc( y_1, eita, w, t, theta)             

y=(y_1/(sqrt(1-eita))) * (exp(-1*eita*w*t))*sin((w*sqrt(1-(eita*eita))*t)+theta);

end

a=1; t=0.1;                                                                    

while(t<10)

y1(a)=sinfunc(0.15,3/(2*sqrt(2)),sqrt(2),t,0);

y2(a)=sinfunc(0.15,1/(2*sqrt(2)),sqrt(2),t,0);

a=a+1;

t=t+0.1;

end

plot(y1);

plot(y2);

 

 Out Put :

 

 

Question # 2

Use ‘for’ or ‘while’ loop to convert  degrees Fahrenheit (Tf) to degrees Celsius using the following equation .  Use any starting temperature, increment and ending temperature

Solution:

Open the function file from matlab and write the following code and save it with “ctf”.

 

function f = ctf( c );            %function decleration

f = ((9/5)*c)+32;

 t=0;

while(t<200)

Tf(i)=ctf(t);

i=i+1;

t=t+10;

end

Tf

Tf =

 

  Columns 1 through 15

    32    50    68    86   104   122   140   158   176   194   212   230   248   266   284

  Columns 16 through 20

   302   320   338   356   37

 

Question # 3

Plot the function

                        Y(x)=exp(-x)sin(8x)  for  0<=x<=2π

Solution:

Open the function file and type the following command in the function file and save it with “ func”.

 

function y = func(x)                          % function decleration

y=exp(-x)*sin(8*x);

 command window .

i=1;                                        

x=0;

while(x<=(2*pi))

y(i)=func(x);

i=i+1;

x=x+0.1;

end

plot(y)