MATLAB第六次上机实验报告

MATLAB第六次上机实验报告

0210901班学号2009210811 姓名：李贤凤Quiz 3.1

>> a=20;

>> b=-2;

>> c=0;

>> d=1;

>> a>b

ans =

1

>> b>d

ans =

>> a>b&c>d

ans =

>> a==b

ans =

>> a&b>c

ans =

>> ~~b

ans =

1

>> a=2;

>> b=[1 -2;-0 10];

>> c=[0 1;2 0];

>> d=[-2 1 2;0 1 0];

>> ~(a>b)

ans =

0 0

0 1

>> a>c&b>c

ans =

1 0

0 1

>> c<=d

??? Error using ==> <=

Matrix dimensions must agree.

>> a=2;

>> b=3;

>> c=10;

>> d=0;

>> a*b^2>a*c

ans =

>> d|b>a

ans =

1

>> (d|b)>a

ans =

>> a=20;

>> b=-2;

>> c=0;

>> d='Test';

>> isinf(a/b)

ans =

>> isinf(a/c)

Warning: Divide by zero.

(Type "warning off MATLAB:divideByZero" to suppress this warning.)

ans =

1

>> a>b&ischar(d)

ans =

1

>> isempty(c)

ans =

Quiz3.2

1．% Script file : Sqrt_x.m

% Purpose:

% This program is used to calculate the square root of a randem number

% Record of revisions:

% Date Programmer Description of change % === ======== ================ % 10/22/2010 lixianfeng Original code

% Define variables :

% x --x is a randem number

% y --y is a function of the sqrt(x)

% Prompt the user for the value x

x=input('Enter the number of x:');

% Calculate the function sqrt(x)

if x>=0

y=sqrt(x);

fprintf('The square root of x is:%f',y);

else

disp('It is an error message about the square root function ');

disp('The value of sqrt is 0');

end

example:test a

Enter the number of x:5

The square root of x is: 2.236068

Enter the number of x:-2

It is an error message about the square root function

The value of sqrt is 0

2. % Script file : Scores.m

% Purpose:

% This program is used to calculate the numerator / denominator

% Record of revisions:

% Date Programmer Description of change

% ==== ========== =================== % 10/22/2010 Li xianfeng Original code

% Define variables :

% fun --fun is calculated as numerator / denominator

% Prompt the user for the value numerator and denominator

numerator=input('Enter the numerator:');

denominator=input('Enter the denominator:');

% Calculate the function numerator / denominator

if abs(denominator)>=1.0E-300

fun=numerator / denominator ;

fprintf('The numerator / denominator is:%f',fun);

else

disp('Divide by 0 error ');

end

example: >> test c

Enter the numerator:4

Enter the denominator:6

The numerator / denominator is0.666667

>> test c

Enter the numerator:3

Enter the denominator:-5E-400

Divide by 0 error

3. % Script file :cost.m

% Purpose:

% This program is used to calculate the cost per mile for a rented vehicle

% Record of revisions:

% Date Programmer Description of change

% ==== ========== =================== % 10/22/2010 Li xianfeng Original code

% Define variables :

% d --d is the distance

% aver --the average cost per mile

% Prompt the user for the value distance

d=input('Enter the distance:');

% Calculate the function

if d>300

disp('The cost per mile for a tented vehicleis $0.20 ');

elseif d>100

aver=(100*0.50+(d-100)*0.30)/d;

disp(['The average cost per mile is ' num2str(aver)]);

elseif d>=0

disp('The average cost per mile is $0.50');

else

disp('The distance should be 0 or positive number ');

end

example: Enter the distance:325

The cost per mile for a tented vehicleis $0.20

>> test3

Enter the distance:158

The average cost per mile is 0.42658

>> test3

Enter the distance:38

The average cost per mile is $0.50

>> test3

Enter the distance:-23

The distance should be 0 or positive number

4. if volts>125

disp('WARNING:High voltage on line.');

if volts<105

disp('WARNING:Low voltage on line.');

else

disp('Line voltage is within tolerances.');

end

Ans:There is no …Input? sentence and the second “if” should be replaced by “elseif” or add

a “end” at the end of program..

5. color = 'yellow';

switch (color)

case 'red',

disp('stop now!');

case 'yellow',

disp('prepare to stop.');

case 'green',

disp('proceed through intersection.');

otherwise,

disp('illegal color encountered.');

end

Ans: prepare to stop.

6. if temperature>100

disp('human body temperature exceeded.');

elseif temperature>37

disp('boiling point of water exceeded.');

end

Ans: Undefined function or variable 'temperature'.

3.8 Exercises:

3.1% Script file :tan(theta).m

% Purpose:

% This program is used to evaluate the tangent function

% tan_theta=sin(theta)/cos(theta)

% Record of revisions:

% Date Programmer Description of change

% ==== ========== ================

% 10/22/2010 Li xianfeng Original code

% Define variables :

% theta --the angle

% tan --the tangent function

% sin --the tangent function

% cos --the tangent function

% Prompt the user for the value theta

theta=input('Enter the theta:');

% Calculate the function

if cos(theta)<1e-20

disp('error message');

else

tan_theta=sin(theta)/cos(theta);

disp(['The tan_theta is ' num2str(tan_theta)]);

end

example: Enter the theta:5

error message

>> test3_1

Enter the theta:0.05

The tan_theta is 0.050042

3.2 Ans:The logical order is wrong,the last”elseif” shoude be corrected by “else”and there lack a

intput sentence.

if temp>103.0

disp('Temperature dangerously high');

elseif temp>99.5

disp('Temperature slightly high');

elseif temp>97.5

disp('Temperature normal');

else temp<97.5

disp('Temperature below normal');

end

example: enter the Temperature:88

temp =

88

Temperature below normal

enter the Temperature:98

temp =

98

Temperature normal

enter the Temperature:101

temp =

101

Temperature slightly high

enter the Temperature:121

temp =

121

Temperature dangerously high

3.3 % Script file :cost.m

% Purpose:

% This program is used to calculate the cost of sending a package

% Record of revisions:

% Date Programmer Description of change

% ==== ========== =================== % 10/22/2010 Li xianfeng Original code

% Define variables :

% weight --the weight of package

% cost --the cost of sending a package

% Prompt the user for the value weight

weight=input('Enter the weight:');

% Calculate the function

if weight>100

disp('the package is not accepted!!!');

elseif weight>70

cost=10+3.75*68+(weight-70);

disp(['The cost of sending a package is $' num2str(cost)]);

elseif weight>2

cost=10+3.75*(weight-2);

disp(['The cost of sending a package is $' num2str(cost)]);

elseif weight>0

cost=10;

disp('The cost of sending a package is $10.00' );

else

disp('the weight can?t be a negative number.')

end

3.4 % Script file :funxy.m

% Purpose:

% This program is solving the function f(x,y) for a user-specified x and y

% ,where f(x,y) is defined as:

% -

% | x+y x>=0 and y>=0

% f(x,y)= | x+y^2 x>=0 and y<0

% | x^2+y x<0 and y>=0

% | x^2+y^2 x<0 and y<0

% -

% Record of revisions:

% Date Programmer Description of change % ==== ========== =============== % 10/22/2010 LI xianfeng Original code

% Define variables :

% x --the first independent variable

% y --the second independent variable

% fun --resulting function

% Prompt the user for the value x

x=input('Enter the x coefficient:');

y=input('Enter the y coefficient:');

% Calculate the function fun(x,y) based on the signs of x and y.

if x>=0 & y>=0

fun=x+y;

else

if x>=0 & y<0

fun=x+y^2 ;

else

if x<0 & y>=0

fun=x^2+y;

else

fun=x^2+y^2;

end

end

end

% write the value of the function

disp(['the value of the function is ' num2str(fun)]);

3.5 % Script file :lnx.m

% Purpose:

% This program is solving the function ln(1/(1-x)) for a user-specified x and y

% Record of revisions:

% Date Programmer Description of change

% ==== ========== =================== % 10/22/2010 Li xianfeng Original code

% Define variables :

% x --the independent variable

% y --the function of ln(1/(1-x))

% ln --the natural logarithm,the logarithm to the base e.

% Prompt the user for the value x

x=input('Enter the x :');

% Calculate the function ln(1/(1-x)) based upon the signs of x .

if x<1

y=log(1/(1-x));

disp(['the value of ln(1/(1-x)) is;' num2str(y)]);

else

disp('the variable must be positive number.');

end

example: Enter the x :-9

the value of ln(1/(1-x)) is;-2.3026

Enter the x :8

the variable must be positive number