các dạng bài tập ôn thi matlab

(phương pháp chia đôi) F=(x) (x3)14xx+59x70; xl=1.8; yl=F(xl); xr=2.1; yr=F(xr); while (xrxl)>eps xm=(xl+xr)2; ym=F(xm); if sign(yl)~=sign(ym) xr=xm; else xl=xm; end end xm Incremental Search method (Ppdaycung) F=(x) (x3)14xx+59x70; x2=input(x2: ); delta=0.3; y2=F(x2); y1=y2; while y2y1>0 x1=x2; x2=x1+delta; y2=F(x2); end y3=1+eps; eps=1E6; while abs(y3)>eps x3=(x1y2x2y1)(y2y1); y3=F(x3); if sign(y3)~=sign(y1) x2=x3; y2=y3; else x1=x3; y1=y3; end end x3 Secant method (PPdaycung2) F=(x) (x3)14xx+59x70; x2=input(x2: ); delta=0.3; y2=F(x2); y1=y2; while y2y1>0 x1=x2; x2=x1+delta; y2=F(x2); end x3=x2; y3=y2; x2=x1; y2=y1; eps=1E6; while abs(x3x2)>eps x1=x2; y1=y2; x2=x3; y2=y3; x3=(x1y2x2y1)(y2y1); y3=F(x3); end x3

Chưng cất

Pmt=input('Pmt: ');

a1=input('a1: ');

a2=input('a2: ');

b1=input('b1: ');

b2=input('b2: ');

N=input('So mam N: ');

x=input('phan mol x: ');

T1=a1/(log(Pmt)-b1);

T2=a1/(log(Pmt)-b2);

if T1>T2

tmp=a1;a1=a2;a2=tmp;

tmp=b1;b1=b2;b2=tmp;

tmp=T1;T1=T2;T2=tmp;

end

eps=1E-10;

F = @(x,T) x*exp(a1/T1+b1)+(1-x)*exp(a2/T1+b2)-Pmt; fprintf('man\t long\t hoi\t NDsoi\n')

for i=1:N

A=T1;

B=T2;

while (B-A)>eps

mid=(A+B)/2;

if F(x,mid)==0;

B=mid;

A=B;

else

if sign(F(x,A))==sign(F(x,mid))

A=mid;

else B=mid;

end

end

end

T=(A+B)/2;

y=x*exp(a1/T+b1)/Pmt;

fprintf('%6.0f\t %6.4f\t %6.4f\t %6.3f\n',i,x,y,T-273); x=y;

end

Switch, case anh otherwise

input_num=input('nhap so: ');

switch input_num

case -1

input_str='minus one';

case 0

input_str='zero';

case 1

input_str='plu one';

case {-10,10}

input_str='+/-ten';

otherwise

input_str='other value';

display(input_str)

The while loop

i=1;j=10;

while i<=N

j=1;

while j<=N

A(i,j)=1/(i+j-1);

j=j+1;

end

i=i+1;

end

Tích phân theo MonteCarlo

N=input('N: ');

a=input('a: ');

b=input('b: ');

sum=0;

for i=1:N

x=a+(b-a)*rand;

y=x*x;

sum=sum+y;

end

h=sum/N;

TP=h*(b-a);

fprintf('TP= %0.2f',TP)

Tích phân theo MonteCarlo 3D

N=input('N: ');

xL=input('xL: ');

xU=input('xU: ');

yL=input('yL: ');

yU=input('yU: ');

zL=input('zL: ');

zU=input('zU: ');

sum=0;

V=(xU-xL)*(yU-yL)*(zU-zL);

for i=1:N

x=xL+rand*(xU-xL);

y=yL+rand*(yU-yL);

z=zL+rand*(zU-zL);

F=x*x+y*y+z*z;

sum=V+F;

TP=sum*V/i

fprintf('TP= %0.2f',TP)

end

Vận tốc khí theo nhiệt độ

T1=input('gt T1: ');

T2=input('gt T2: ');

BN=input('gt buoc nhay BN: ');

M1=input('gt M1: ');

M2=input('gt M2: ');

fprintf('bang gia tri VTTB u1 va u2 theo T:\n');

for T=T1:BN:T2

u1=sqrt((3*R*T)/M1);

u2=sqrt((3*R*T)/M2);

fprintf('T= %d\t, u1= %0.2f\t, u2= %0.2f\n',T,u1,u2);

end

Vận tốc trung bình của phân tử khí theo nhiệt độ

T=input('temperature is K: ');

Po=input('outside pressure is atm: ');

Pi=input('inside pressure is atm: ');

M=input('Molecule weight: ');

K=input('Cp/Cv: ');

% R=8.314J/(K.mol)

% 1J=1E7 erg

% 1 erg=1cm^2*g/(s^2)

R=8.314*1E7; %change R

K9=(K-1)/K;

P9=Po/Pi;

R9=R*T/M;

u=sqrt(2/K9*R9*(1-P9^K9))/100;

fprintf('vt : %g.\n',u)

Euler, RK4

F=@(x,t) (10-x)/10;

time=60;

h=time/N;

t=linspace(0,time,N+1);

CA_Euler=zeros(0,N+1);

CA_Euler(i)=1;

hold on;

for i=1:N

CA_Euler(i+1)=CA_Euler(i)+h*F(CA_Euler(i),t(i));

end

plot(t,CA_Euler,'red')

CA_E_improved=zeros(0,N+1);

CA_E_improved(i)=1;

for i=1:N

k1=h*F(CA_E_improved(i),t(i));

k2=h*F(CA_E_improved(i)+k1,t(i)+h)

CA_E_improved(i+1)=CA_E_improved(i)+(k1+k2)/2;

end

plot(t,CA_E_improved,'blue')

CA_E_modified=zeros(0,N+1);

CA_E_modified(i)=1;

for i=1:N

k1=h*F(CA_E_modified(i),t(i));

CA_E_modified(i+1)=CA_E_modified(i)+h*F(CA_E_modified(i)+k1/2,t(i)+h/2);

plot(t,CA_E_modified,'y')

RK4=zeros(0,N+1);

RK4(i)=1;

for i=1:N

k1=h*F(RK4(i),t(i));

k2=h*F(RK4(i)+k1/2,t(i)+h/2);

k3=h*F(RK4(i)+k2/2,t(i)+h/2);

k4=h*F(RK4(i)+k3,t(i)+h);

RK4(i+1)=RK4(i)+(k1+2*k2+2*k3+k4)/6;

end

plot(t,RK4,'black')

CA=10-9*exp(-t/10);

plot(t,CA,'green')

Hệ số truyền nhiệt

x=input('x: ');

t=input('t: ');

L=input('L: ');

eps=input('eps: ');

k=100;

T=10+10*x;

i=1;

flag=true;

fprintf('step\t term\t\t sum\n');

while flag

an=(30/(i*pi))*(-2)*exp((-2*i^2*pi^2*t)/(k*L^2));

an=an*sin(i*pi*x/L);

T=T+an;

fprintf('%2.0f\t %e\t %5.2f\n',i,an,T);

i=i+2;

if (abs(an)<eps)

flag=false;

end

end

The if, elseif and else statements

I=input('nhap gia tri I=');

J=input('nhap gia tri J=');

if I==J

A(I,J)=2;

elseif abs(I-J)==1

A(I,J)=-1;

else

A(I,J)=0;

end

Bài thi giữa kì

clc;

clear all;

D=input('Nhap duong kinh ong D(m): ');

u=input('Nhap do nhot u(kg/m.s): ');

p=input('Nhap khoi luong rieng p(kg/m3): ');

v=input('Nhap van toc trung binh dong v(m/s): ');

Re=p*v*D/u;

if Re<=2300

hf=16/Re;

fprintf('He so ma sat la: %5.2f.\nRe dong chay tang la: %5.2f.\n',hf,Re) else Re>2300;

hf=0.079*Re^-0.25;

fprintf('He so ma sat la: %5.2f.\nRe dong chay roi la: %5.2f.\n',hf,Re) end

Gỉai phương trình bậc 2

a=input('nhap gia tri a = ');

b=input('nhap gia tri b = ');

c=input('nhap gia tri c = ');

delta = b^2-4*a*c;

if delta>0

X1=(-b+sqrt(delta))/(2*a);

X2=(-b-sqrt(delta))/(2*a);

fprintf('nghiem cua gia tri X1 la %4.2f, X2 la %4.2f',X1,X1);

elseif delta<0

fprintf('phuong trinh vo nghiem');

else

X=-b/(2*a);

fprintf('nghiem cua phuong trinh la X %4.2f',X);

end

Bisection method (phương pháp chia đôi)

F=@(x) (x^3)-14*x*x+59*x-70;

xl=1.8;

yl=F(xl);

xr=2.1;

yr=F(xr);

while (xr-xl)>eps

xm=(xl+xr)/2;

ym=F(xm);

if sign(yl)~=sign(ym)

xr=xm;

else

xl=xm;

end

end

xm

Incremental Search method (Ppdaycung)

F=@(x) (x^3)-14*x*x+59*x-70;

x2=input('x2: ');

delta=0.3;

y2=F(x2);

y1=y2;

while y2*y1>0

x1=x2;

x2=x1+delta;

y2=F(x2);

end

y3=1+eps;

eps=1E-6;

while abs(y3)>eps

x3=(x1*y2-x2*y1)/(y2-y1);

y3=F(x3);

if sign(y3)~=sign(y1)

x2=x3;

y2=y3;

else

x1=x3;

y1=y3;

end

end

x3

Secant method (PPdaycung2)

F=@(x) (x^3)-14*x*x+59*x-70;

x2=input('x2: ');

delta=0.3;

y2=F(x2);

y1=y2;

while y2*y1>0

x1=x2;

x2=x1+delta;

y2=F(x2);

end

x3=x2;

y3=y2;

x2=x1;

y2=y1;

eps=1E-6;

while abs(x3-x2)>eps

x1=x2;

y1=y2;

x2=x3;

y2=y3;

x3=(x1*y2-x2*y1)/(y2-y1);

y3=F(x3);

end

x3

Phương pháp dò tìm

FNF=@(x) (x^3)-14*x*x+59*x-70

delta=0.3;

x_new=0;

y_new=FNF(x_new);

y_old=y_new;

while y_new*y_old>0

x_old=x_new;

x_new=x_new+delta;

y_new=FNF(x_new);

end

x_old

x_new

Fixed-point iteration method

Kw=10^-14;

Ka=input('Ka: ');

Ca=input('Ca: ');

F=@(x) Kw/x+Ka*Ca/(Ka+x);

x2=1E-7;

x1=x2+1;

eps=1E-6;

while abs(x1-x2)>eps

x1=x2;

x2=F(x1);

end

PH=-log10(x2);

fprintf('PH=%6.4f\n',PH)

Newton-Raphson method

F=@(x) (x^3)-14*x*x+59*x-70;

D=@(x) 3*(x^2)-28*x+59;

x2=input('x2: ');

x1=x2+1+eps;

while abs(x1-x2)>eps

x1=x2;

x2=x1-(F(x1)/D(x2));

y2=D(x2);

end

x2

Quy luật phân bố vận tốc

T=input('temperature is K: ');

M=input('molecular weight: ');

U=input('molecular velocity: ');

% R=8.31441J/(K.mol)

% 1J=E7erg

% 1erg=1cm^2*g/(a^2)

R=8.314;

RH=8.314*1E7; %change R

UH=U*100; %change velocity to cm/s

dN=4*pi*UH*UH*(M/(2*pi*RH*T))^(3/2);

dN=dN*exp(-M*UH*UH/(2*RH*T));

dN=dN*100;

fprintf('partic: %g.\n',dN)

Gía trị trung bình và sai số chuẩn

x=[5 5.5 3 7.2 8.1 5.95 4.7 4 6.05];

N=length(x);

M=0;

for i=1:N

M=N+x(i);

S=S+x(i)^2;

end

M=N/N;

S=S-N*M^2;

S=sqrt(S/(N-1));

fprintf('Mean value: %g.\n',N)

fprintf('Standard diviation: %g.\n',S)

Chuỗi Fourier

x=input('x: ');

eps=input('eps: ');

s=1;

i=1;

flag=true;

fprintf('step\t last term\t\t sum\n');

while flag

i=i+2;

an=((2/i*pi)^2)*(-2)*cos((i*pi*x)/2);

s=s+an;

fprintf('%2.0f\t %e\t %5.2f\n',i,an,s);

if (abs(an)<eps)

flag=false;

end

end

Chuỗi hình học

an=input('an: ');

q=input('q: ');

eps=input('error; ');

i=0;s=an; %first term first sum

flag=true;

fprintf('step\t last term \t\t sum\n');

while flag

an=an*q;

s=s+an;

fprintf('%2.0f\t %e\t %9.5f\n',i,an,s);

i=i+1;

if abs(an)<(eps*(1-q))

flag=false;

end

end

1

k1=0.2;

k2=0.1;

F=@(Ca,Cb,t) -k1*Ca;

G=@(Ca,Cb,t) k1*Ca-k2*Cb;

time=50;

h=time/N;

Ca(1)=Ca0;

Cb(1)=0;

t=linspace(0,time,N+1);

Ca=zeros(0,N+1);

Ca(i)=1;

for i=1:N

k1a=h*F(Ca(i),Cb(i),t(i));

k1b=h*G(Ca(i),Cb(i),t(i));

k2a=h*F(Ca(i)+k1a/2,Cb(i)+k1b/2,t(i)+h/2); k2b=h*G(Ca(i)+k1b/2,Cb(i)+k1b/2,t(i)+h/2); k3a=h*F(Ca(i)+k2a/2,Cb(i)+k2b/2,t(i)+h/2); k3b=h*G(Ca(i)+k2a/2,Cb(i)+k2b/2,t(i)+h/2); k4a=h*F(Ca(i)+k3a,Cb(i)+k3b,t(i)+h);

k4b=h*G(Ca(i)+k3a,Cb(i)+k3b,t(i)+h);

Ca(i+1)=Ca(i)+(k1a+2*k2a+2*k3a+k4a)/6; Cb(i+1)=Cb(i)+(k1b+2*k2b+2*k3b+k4b)/6; end

CC=Ca0-(Ca+Cb);

plot(t,Ca);

hold on

plot(t,Cb);

2

clc;

clear all;

FNF=@(x,t) (10-x)/10;

N=10;

time=60;

h=time/N;

t=linspace(0,time,N+1);

ca_euler=zeros(0,N+1);

ca_euler(1)=1;

hold on;

for i=1:N

ca_euler(i+1)=ca_euler(i)+h*FNF(ca_euler(i),t(i)); end

plot(t,ca_euler,'b');

ca_improved=zeros(0,N+1);

ca_improved(1)=1;

for i=1:N

k1=h*FNF(ca_improved(i),t(i));

k2=k1+h*FNF(ca_improved(i),t(i)+h);

ca_improved(i+1)=ca_improved(i)+(k1+k2)/2;

plot(t,ca_improved,'p');

ca_modified=zeros(0,N+1);

ca_modified(1)=1;

for i=1:N

k1=h*FNF(ca_modified(i),t(i));

ca_modified(i+1)=ca_modified(i)+h*FNF(ca_modified(i)+k1/2,t+h/2); end

plot(t,ca_modified,'g');

r_o=zeros(0,N+1);

r_o(1)=1;

for i=1:N;

k1=h*FNF(r_o(i),t(i));

k2=h*FNF(r_o(i)+k1/2,t(i)+h/2);

k3=h*FNF(r_o(i)+k2/2,t(i)+h/2);

k4=h*FNF(r_o(i)+k3,t(i)+h);

r_o(i+1)=r_o(i)+1/6*(k1+2*k2+2*k3+k4);

end

plot(t,r_o,'red');