solving trascendental equations, proper setting
2 次查看(过去 30 天)
显示 更早的评论
Hello everybody,
I'd like to solve for y = y(x) the following equation
d log( y ) / d x + y = 1 + f
with f = f(x).
f is a 1D numerically known array, I don't know its nalytical form.
I cannot set properly solve or fzero.
Can you help me, please?
Patrizio
0 个评论
采纳的回答
Ameer Hamza
2020-6-14
编辑:Ameer Hamza
2020-6-14
This is a differential equation and you can use symbolic toolbox to find an anayltical solution
syms y(x) f
eq = diff(log(y), x) + y == 1 + f;
sol = dsolve(eq);
Result
>> sol
sol =
(exp((C1 + x)*(f + 1))*(f + 1))/(exp((C1 + x)*(f + 1)) + 1)
f + 1
Following shows how to get a numerical solution using ode45
syms y(x) f
eq = diff(log(y), x) + y == 1 + f;
sol = dsolve(eq);
odeFun = matlabFunction(odeToVectorField(eq), 'Vars', {'t', 'Y', 'f'});
tspan = [0 10]; % time span for numerical solution
ic = 1; % initial condition: y(0)==1
fv = 1; % numerical solution for f=1
[t, y] = ode45(@(t, y) odeFun(t, y, fv), tspan, ic);
plot(t, y);
7 个评论
Ameer Hamza
2020-6-17
I am glad that it worked for your case, and you got the results. Good luck with your research.
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Calculus 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!