Please someone help test run this Matlab code and debug it if possible. Please help a student
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Omorodion Solomon
on 24 Jul 2021
Commented: Star Strider
on 31 Jul 2021
alpha=input('simulation time alpha=') [x,t] = meshgrid(-4:.1:4, 0.1:.2:0.4); exact=(sech(x/4-t/4)).^2 f0=(sech(x/4)).^2 f1=1/2.*(sech(x/4)).^2.*tanh(x/4)+1/2.*(sech(x/4)).^4.*tanh(x/4) f2=7/8.*(sech(x/4)).^6.*(tanh(x/4)).^2-1/8.*(sech(x/4)).^6 +5/4.*(sech(x/4)).^4.*(tanh(x/4)).^2-1/4.*(sech(x/4)).^4 +3/8.*(sech(x/4)).^2.*(tanh(x/4)).^2-1/8.*(sech(x/4)).^2 f3=35/16.*(sech(x/4)).^8.*(tanh(x/4)).^3-11/6.*(sech(x/4)).^8.*tanh(x/4) +17/4.*(sech(x/4)).^6.*(tanh(x/4)).^3-13/8.*((sech(x/4))).^6.*tanh(x/4) +39/16.*(sech(x/4)).^4.*(tanh(x/4)).^3-19/16.*(sech(x/4)).^4.*tanh(x/4) +3/8.*(sech(x/4)).^2.*((tanh(x/4)).^3)-1/4.*(sech(x/4)).^2.*tanh(x/4) f4=385/64.*(sech(x/4)).^8.*(tanh(x/4)).^4-35/16.*sech(x/4).*tanh(x/4)-51/16 .*(sech(x/4)).^8.*(tanh(x/4)).^2+153/16.*(sech(x/4)).^6.*(tanh(x/4)).^4 +11/16.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^8.*tanh(x/4) .*(-1/2.*(sech(x/4)).^2.*tanh(x/4))-17/4.*sech(x/4).*(-1/2.*(sech(x/4)).^2 .*tanh(x/4)).^6.*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^3+11/64 .*(sech(x/4)).^8-193/32.*(sech(x/4)).^6.*(tanh(x/4)).^2+273/64 .*(sech(x/4)).^4.*(tanh(x/4)).^4+13/8.*sech(x/4).*(-1/2*(sech(x/4)).^2).^6 .*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4))-39/16.*sech(x/4) .*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^7.*tanh(x/4)+13/32.*(sech(x/4)).^6 -53/16.*(sech(x/4)).^4.*(tanh(x/4)).^2+15/32.*(sech(x/4)).^2 .*(tanh(x/4)).^4+19/16.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^5 .*tanh(x/4)-3/8.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^5.*tanh(x/4) +19/64.*(sech(x/4)).^4-15/32.*(sech(x/4)).^2.*(tanh(x/4)).^2+1/4.*sech(x/4) .*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^3-sech(x/4)-35/8 .*(sech(x/4)).^8.*(tanh(x/4)).^4+105/16.*(sech(x/4)).^8.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+11/8.*(sech(x/4)).^8.*(tanh(x/4)).^4-11/16 .*(sech(x/4)).^.8.*(1/4-1/4.*(tanh(x/4)).^2)-51/.8.*(sech(x/4)).^.6 .*(tanh(x/4)).^4+51/4.*(sech(x/4)).^6.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+39/16.*(sech(x/4)).^6.*(tanh(x/4)).^2 -13/8 .*(sech(x/4)).^6.*(1/4-1/4.*(tanh(x/4)).^2)-39/16.*(sech(x/4)).^4 .*(tanh(x/4)).^4+117/16.*(sech(x/4)).^4.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+19/16.*(sech(x/4)).^4.*(tanh(x/4)).^2-19/16 .*(sech(x/4)).^4.*(1/4-1/4.*(tanh(x/4)).^2)-3/16.*(sech(x/4)).^2 .*(tanh(x/4)).^4+9/8.*(sech(x/4)).^2.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+1/8.*(sech(x/4)).^2.*(tanh(x/4)).^2-1/4 .*(sech(x/4)).^2.*(1/4-1/4.*(tanh(x/4)).^2).^2+1/16.*(sech(x/4)).^2 u4=f0+f1.*((t.^alpha)/gamma(1+alpha))+f2.*((t.^(2.*alpha))/gamma(1+2.*alpha ))+f3.*((t.^(3.*alpha))/gamma(1+3.*alpha))+f4.*((t.^(4.*alpha))/gamma(1+4.* alpha)) Z1=uexact mesh(t,x,Z1) Z2=u4 mesh(t,x,Z2)
2 Comments
Yongjian Feng
on 24 Jul 2021
If you can format it better, others might be able to understand what it is.
Accepted Answer
Star Strider
on 24 Jul 2021
The ‘uexact’ variable does not exist, and there is nothing similar to it (for example by a different spelling, at least that I can see) in the code. Substituting ‘exact’ for it (that does exist) produces a mesh plot.
Otherwise, ‘uexact’ will need to be created for the code to work, since that appears to be the only probllem. (The input call does not work in the onlilne Run feature, so I assigned the ‘alpha’ value separately. I have no idea what it should be , so change it if the value I chose is not appropriate.)
% alpha=input('simulation time alpha=')
alpha = 100;
[x,t] = meshgrid(-4:.1:4, 0.1:.2:0.4);
exact=(sech(x/4-t/4)).^2
f0=(sech(x/4)).^2
f1=1/2.*(sech(x/4)).^2.*tanh(x/4)+1/2.*(sech(x/4)).^4.*tanh(x/4)
f2=7/8.*(sech(x/4)).^6.*(tanh(x/4)).^2-1/8.*(sech(x/4)).^6 +5/4.*(sech(x/4)).^4.*(tanh(x/4)).^2-1/4.*(sech(x/4)).^4 +3/8.*(sech(x/4)).^2.*(tanh(x/4)).^2-1/8.*(sech(x/4)).^2
f3=35/16.*(sech(x/4)).^8.*(tanh(x/4)).^3-11/6.*(sech(x/4)).^8.*tanh(x/4) +17/4.*(sech(x/4)).^6.*(tanh(x/4)).^3-13/8.*((sech(x/4))).^6.*tanh(x/4) +39/16.*(sech(x/4)).^4.*(tanh(x/4)).^3-19/16.*(sech(x/4)).^4.*tanh(x/4) +3/8.*(sech(x/4)).^2.*((tanh(x/4)).^3)-1/4.*(sech(x/4)).^2.*tanh(x/4)
f4=385/64.*(sech(x/4)).^8.*(tanh(x/4)).^4-35/16.*sech(x/4).*tanh(x/4)-51/16 .*(sech(x/4)).^8.*(tanh(x/4)).^2+153/16.*(sech(x/4)).^6.*(tanh(x/4)).^4 +11/16.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^8.*tanh(x/4) .*(-1/2.*(sech(x/4)).^2.*tanh(x/4))-17/4.*sech(x/4).*(-1/2.*(sech(x/4)).^2 .*tanh(x/4)).^6.*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^3+11/64 .*(sech(x/4)).^8-193/32.*(sech(x/4)).^6.*(tanh(x/4)).^2+273/64 .*(sech(x/4)).^4.*(tanh(x/4)).^4+13/8.*sech(x/4).*(-1/2*(sech(x/4)).^2).^6 .*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4))-39/16.*sech(x/4) .*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^7.*tanh(x/4)+13/32.*(sech(x/4)).^6 -53/16.*(sech(x/4)).^4.*(tanh(x/4)).^2+15/32.*(sech(x/4)).^2 .*(tanh(x/4)).^4+19/16.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^5 .*tanh(x/4)-3/8.*sech(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^5.*tanh(x/4) +19/64.*(sech(x/4)).^4-15/32.*(sech(x/4)).^2.*(tanh(x/4)).^2+1/4.*sech(x/4) .*tanh(x/4).*(-1/2.*(sech(x/4)).^2.*tanh(x/4)).^3-sech(x/4)-35/8 .*(sech(x/4)).^8.*(tanh(x/4)).^4+105/16.*(sech(x/4)).^8.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+11/8.*(sech(x/4)).^8.*(tanh(x/4)).^4-11/16 .*(sech(x/4)).^.8.*(1/4-1/4.*(tanh(x/4)).^2)-51/.8.*(sech(x/4)).^.6 .*(tanh(x/4)).^4+51/4.*(sech(x/4)).^6.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+39/16.*(sech(x/4)).^6.*(tanh(x/4)).^2 -13/8 .*(sech(x/4)).^6.*(1/4-1/4.*(tanh(x/4)).^2)-39/16.*(sech(x/4)).^4 .*(tanh(x/4)).^4+117/16.*(sech(x/4)).^4.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+19/16.*(sech(x/4)).^4.*(tanh(x/4)).^2-19/16 .*(sech(x/4)).^4.*(1/4-1/4.*(tanh(x/4)).^2)-3/16.*(sech(x/4)).^2 .*(tanh(x/4)).^4+9/8.*(sech(x/4)).^2.*(tanh(x/4)).^2 .*(1/4-1/4.*(tanh(x/4)).^2)+1/8.*(sech(x/4)).^2.*(tanh(x/4)).^2-1/4 .*(sech(x/4)).^2.*(1/4-1/4.*(tanh(x/4)).^2).^2+1/16.*(sech(x/4)).^2
u4=f0+f1.*((t.^alpha)/gamma(1+alpha))+f2.*((t.^(2.*alpha))/gamma(1+2.*alpha ))+f3.*((t.^(3.*alpha))/gamma(1+3.*alpha))+f4.*((t.^(4.*alpha))/gamma(1+4.* alpha))
% Z1=uexact
Z1 = exact;
figure
mesh(t,x,Z1)
xlabel('t')
ylabel('x')
zlabel('Z_1')
Z2=u4
figure
mesh(t,x,Z2)
xlabel('t')
ylabel('x')
zlabel('Z_2')
Is this the desired result?
.
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