Error using integral (line 85) A and B must be floating point scalars
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Hello,
I have a function below. I have successfully integrated it when the value of d=0.5. However, I want to integrate it for d= 5*10^-6, d=5*10^-5..... . I don't want to change the data points manually and do the integration. I want to define d as a vector and save the final result of the integration as well. When I try to do so I got Matlab error of "Error using integral (line 85) A and B must be floating point scalars."
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/161621/image.png)
Any help is appreciated.
clear all clc format long
% definition of constants
% d= 5*10^-1;
d=linspace(5*10^-6,5*10^-3,100);
q=1.6*10^(-19);
k=1.38*10^(-23);
Lb= 44*10^-6;
phi=90*10^-3;
T=293;
f = @(x) (4*k*T/q)*( atanh(tanh(q*phi/(4*k*T))*exp(-x/Lb)) + atanh(tanh(q*phi/(4*k*T))*exp(-(2*d-x)/Lb)));
fun=@(x) 1./(cosh(q.*f(x)./(k*T)));
rho_ap= (2./d).*integral(fun,0,d./2);
0 commentaires
Réponse acceptée
Star Strider
le 13 Mar 2017
It is not obvious to me what you want to do. I would not use a vector for ‘d’ if you only need to evaluate your integral at 2 values of ‘d’.
See if this does what you want:
dv = [5E-6 5E-3];
q=1.6E-19;
k=1.38E-23;
Lb= 44E-6;
phi=90E-3;
T=293;
f = @(x,d) (4*k*T/q)*( atanh(tanh(q*phi/(4*k*T))*exp(-x/Lb)) + atanh(tanh(q*phi/(4*k*T))*exp(-(2*d-x)/Lb)));
fun=@(x,d) 1./(cosh(q.*f(x,d)./(k*T)));
for k1 = 1:length(dv)
rho_ap(k1) = (2./d(k1)).*integral(@(x) fun(x,dv(k1)), 0, dv(k1)/2);
end
2 commentaires
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Numerical Integration and Differentiation dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!