Non linear equation containing integral
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I am bit new with matlab programming. I want to solve the above equation for phi0 but getting problem using solve function. Please help me. I expect a solution like this: different phi0 for different Nt

clc;clear;close all;
warning('off')
% number of data points for r, R and Et-Ef
N = 100;
% define the parameters
Nd = 1e24;
e = 12*1e-12;
r = 40*1e-9
R = 40*1e-9;
Et_Ef = 0.21*1.6*1e-19;
K = 1.3807e-23;
T = 600;
Nt = 1e11;
q = 1.6e-19;
for j = 1:length(Nt)
% initializing
LHS_vals = [];
RHS_vals = [];
P = [];
% loop to solve LHS - RHS = 0 N times
for i = 1:N
syms phi0
Ld = sqrt(e*K*T/(q^2*Nd));
integrand = @(r)Nd-(Nd.*exp(-1.*(phi0+(1./6).*(r(i)/Ld).^2)));
LHS = integral (integrand,0,40*10^-9);
RHS = 4.*pi.*R.^2.*Nt./(1+2.*exp(Et_Ef + K.*T .*(phi0 + (1/6).*(r(i)./Ld).^2)));
eq = LHS - RHS==0;
phi0 = solve(eq,phi0)
if ~isempty(phi0)
LHS_vals(end+1) = eval(LHS);
RHS_vals(end+1) = eval(RHS);
P(end+1) = phi0;
fprintf('LHS - RHS = %1.2e\n',eval(LHS) - eval(RHS))
end
end
%Plotting the Figure
if ~isempty(P)
figure()
hold on
plot(P,RHS_vals,'r--')
plot(P,LHS_vals,'b--')
hold off
xlabel('\phi_0')
ylabel('LHS,RHS')
ax = gca;
ax.YScale = 'log';
legend('RHS','LHS')
end
end
%plot (r,phi0)
댓글 수: 5
Matt J
2019년 6월 3일
Do the values you are getting solve the equations?
Anil Kumar
2019년 6월 3일
Anil Kumar
2019년 6월 3일
Anil Kumar
2019년 6월 3일
SACHIN VERMA
2020년 5월 29일
sir, i also got stuck in simlar problem, please help if anyone knows how to solve it for complicated functions like above...
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