Dear community, odeint is a library for solving ordinary differential equations and has been discussed several times on this list. After successfully fulfilling the GSOC 2011 we continued working on odeint and we published two papers which are available at the arxiv: http://arxiv.org/abs/1110.3397 http://arxiv.org/abs/1110.3233 We would like to request feedback and/or comments on the implementation and the current status of odeint. The library and the documentation are available at the github: https://github.com/headmyshoulder/odeint-v2 http://headmyshoulder.github.com/odeint-v2/doc/index.html Thank you, Mario and Karsten
On 10/23/11 15:40, Karsten Ahnert wrote:
Dear community,
odeint is a library for solving ordinary differential equations [snip] The library and the documentation are available at the github:
https://github.com/headmyshoulder/odeint-v2 http://headmyshoulder.github.com/odeint-v2/doc/index.html [snip] The page:
http://headmyshoulder.github.com/odeint-v2/doc/boost_sandbox_numeric_odeint/... says: The equations of motion are given by x'' = -x + γ x'. This can be transformed to a system of two coupled first-order differential equations with new variables x and p=x'. To apply numerical integration one first has to design the right hand side of the equation w' = f(w) where in this case w = (x,p): which initially confused me because x was not a new variable as claimed by: new variables x and p=x' I think it would be clearer if it read: with new variables w_1=x and w_2=x'. and then: w = (w_1,w_2) which would emphasize that w was a vector and f was a function taking a vector and returning a vector. -regards, Larry
On 10/25/2011 01:20 PM, Larry Evans wrote:
The page:
http://headmyshoulder.github.com/odeint-v2/doc/boost_sandbox_numeric_odeint/...
says:
The equations of motion are given by x'' = -x + γ x'. This can be transformed to a system of two coupled first-order differential equations with new variables x and p=x'. To apply numerical integration one first has to design the right hand side of the equation w' = f(w) where in this case w = (x,p):
which initially confused me because x was not a new variable as claimed by:
new variables x and p=x'
I think it would be clearer if it read:
with new variables w_1=x and w_2=x'.
and then:
w = (w_1,w_2)
which would emphasize that w was a vector and f was a function taking a vector and returning a vector.
Ok, you are right. It is pedagogical not very clever. I will change it. Btw. this method can always be applied to transform any higher-order ODE into a system of coupled first order ODEs. Best regards, Karsten
-regards, Larry
_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users
participants (2)
-
Karsten Ahnert -
Larry Evans