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MINATI
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What changes should have been made to run the code

Asked by MINATI
on 18 May 2019 at 2:11
Latest activity Commented on by MINATI
on 19 May 2019 at 0:47
%% HERE is the code
format long
wt=pi/2;
t=1;
% t=0.01:0.01:5;
% w=pi/2;
w=wt./t;
R=10;H=2;M=5;Kp=0.5;Gr=5;Gc=5;Kc=1;Pr=7;Sc=0.3;
y=0:0.01:5;
% y=0;
P1=abs(R-H); P2=M+(1/Kp);P3=sym(P2+1i*w);P4=sym(P2-1i*w);
P6=Gr/(P1-P2);P7=Gc/(Kc-P2);P5=(P6+P7);P8=(P1*Pr-P2)/(Pr-1);P9=Gr/(Pr-1);
P10=(Sc*Kc-P2)/(Sc-1);P11=Gc/(Sc-1);P12=-(P11/P10^2)-(P9/P8^2);P13=(P11/P10)+(P9/P8);
T1=(t+(y/2)*(sqrt(Pr/P1))).*exp(y*sqrt(Pr*P1)).*(1-erf((y/2).*sqrt(Pr./t)+sqrt(P1.*t)));
T2=(t-(y/2)*(sqrt(Pr/P1))).*exp(-y*sqrt(Pr*P1)).*(1-erf((y/2)*sqrt(Pr./t)-sqrt(P1.*t)));
C1=(t+(y/2)*(sqrt(Sc/Kc))).*exp(y*sqrt(Sc/Kc)).*(1-erf((y/2)*sqrt(Sc./t)+sqrt(Kc.*t)));
C2=(t-(y/2)*(sqrt(Sc/Kc))).*exp(-y*sqrt(Sc/Kc)).*(1-erf((y/2)*sqrt(Sc./t)-sqrt(Kc.*t)));
T=(T1+T2)/2;C=(C1+C2)/2;
U1=exp(y*sqrt(P2)).*(1-erf(y./(2.*sqrt(t))+ sqrt(P2.*t)));
U2=exp(-y*sqrt(P2)).*(1-erf(y./(2.*sqrt(t))- sqrt(P2.*t)));
U3=exp(y*sqrt(P1*Pr)).*(1-erf((y./2)*sqrt(Pr./t)+ sqrt(P1.*t)));
U4=exp(-y*sqrt(P1*Pr)).*(1-erf((y./2)*sqrt(Pr./t)- sqrt(P1.*t)));
U5=exp(y*sqrt(Sc*Kc)).*(1-erf((y./2)*sqrt(Sc./t)+ sqrt(Kc.*t)));
U6=exp(-y*sqrt(Sc*Kc)).*(1-erf((y./2)*sqrt(Sc./t)- sqrt(Kc.*t)));
U7=exp(y*sqrt(P3)).*(1-erf(y./(2.*sqrt(t))+ sqrt(P3.*t)));
U8=exp(-y*sqrt(P3)).*(1-erf(y./(2.*sqrt(t))- sqrt(P3.*t)));
U9=exp(y*sqrt(P4)).*(1-erf(y./(2.*sqrt(t))+ sqrt(P4.*t)));
U10=exp(-y*sqrt(P4)).*(1-erf(y./(2.*sqrt(t))- sqrt(P4.*t)));
U=(P12/2).*(U1+U2)+(P13/2)*((t+(y/(2*sqrt(P2)))).*U1+(t-(y/(2*sqrt(P2)))).*U2)+((P9/(2*(P8^2))).*exp(-P8.*t)+(P11/(2*(P10^2))).*exp(-P10.*t)).*(U1+U2)+...
(P9/(2*P8^2)).*(U3+U4)-(P9/(2*P8))*((t+(y/2)*sqrt(Pr/P1)).*U3+(t-(y/2)*sqrt(Pr/P1)).*U4)-(P9/(2*P8^2)).*exp(-P8.*t).*(U3+U4)+...
(P11/(2*P10^2)).*(U5+U6)-(P11/(2*P10))*((t+(y/2)*sqrt(Sc/Kc)).*U5+(t-(y/2)*sqrt(Sc/Kc)).*U6)-...
(P11/(2*P10^2)).*exp(-P10.*t).*(U5+U6) +exp(1i*wt)*(1/4).*(U7+U8)+exp(-1i*wt)*(1/4).*(U9+U10);
%% S1: Partial derivative of 'U(t,y)' w.r.t 'y', S2: Partial derivative of 'T(t,y)' w.r.t 'y',
S1= - diff(U,y);
S2= - diff(T,y);
v_t=0.01:0.01:5;
Sk = subs(S1,y,0);
Nu=subs(S2,y,0);
figure(1)
plot(v_t,vpa(subs(Sk,t,v_t)))
xlabel(' t');
ylabel('Sk');
hold on
figure(2)
plot(v_t,vpa(subs(Nu,t,v_t)))
xlabel(' t');
ylabel('Nu');
hold on
%%We need to draw graph of Partial derivative of 'U(t,y)' w.r.t 'y' and 'T(t,y)' w.r.t 'y'
at y=0 for t=0.01:0.01:5;
%% While running the code the following ERROR occurs:
Error using sym/diff (line 69)
The second argument must be a variable or a nonnegative integer specifying the number of differentiations.
Error in (line 37)
S1= - diff(U,y);
%%ANOTHER error for S2 is :
Error using diff
Difference order N must be a positive integer scalar.
Error in (line 38)
S2= - diff(T,y);

  5 Comments

Any help will be appreciated
S1= - diff(U,y);
%............^.....
Here the y value must be in integer as per diff definitions
Y = diff(X,n) calculates the nth difference by applying the diff(X) operator recursively n times.
In your case y is 1x501 double, therefore it reflect an error as below
Error using sym/diff (line 70)
Second argument must be a variable or a nonnegative integer specifying the number of differentiations.
Error in ans_may19 (line 37)
S1= - diff(U,y);
So what changes should we do

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