Differential Equations in Octave - can it solve them?

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Differential Equations in Octave - can it solve them?

pedroso620

Hello!

 

     I am Gabriel, and food engineering student. I have worked on my project, and I need some  tool to solve problems that are mainly differential equations, like: . I like to know whether Octave can solve this type of problem. If so, can you teach me please? I installed package symbolic.

 

Thank you!



Reply | Threaded
Open this post in threaded view
|

Re: Differential Equations in Octave - can it solve them?

BGreen

On Sat, Nov 21, 2020 at 5:53 PM <[hidden email]> wrote:

Hello!

     I am Gabriel, and food engineering student. I have worked on my project, and I need some  tool to solve problems that are mainly differential equations, like: . I like to know whether Octave can solve this type of problem. If so, can you teach me please? I installed package symbolic.

 

Thank you!



Do you want an analytic solution, then, or is a numerical solution sufficient? Here is the documentation for some numerical solvers. Although I am only aware of a symbolic solver for ODEs, here is its documentation as well.


Reply | Threaded
Open this post in threaded view
|

Re: Differential Equations in Octave - can it solve them?

BGreen

On Sat, Nov 21, 2020 at 7:09 PM <[hidden email]> wrote:

    I want an analytic solution. I’d like Octave’s answer for  was . Using symbolic solver for ODEs, the result/answer I get it is shown below.

 

     I don’t know how to solve it.

 


Please always copy in the main help list so everyone can help and so that the community can learn from our messages. Also, please write your response below the previous message when responding to this list, and whenever possible, please copy in the output of the command line instead of posting a screenshot.

It's helpful to read the documentation for diff and for dsolve.

diff(S,S) is not a differential, it is dS/dS=1. You can see this in your code; no term such as dS appears.

If you know the answer, why are you asking Octave to solve it? These integrals can be done analytically by realizing that d/dx ( ln( f(x) ) ) = df/dx / f(x) . I would recommend posting mathematical questions on math.stackexchange.com/, or consulting the thermodynamics textbook where you found this equation.