Thanks, that's great!
El miércoles, 8 de julio de 2015, 19:49:33 (UTC-5), j verzani escribió:
>
> The answer is
>
> dsolve(exs::Vector{Sym};kwargs...) = sympy_meth(:dsolve, exs; kwargs...)
>
> I just added this to the master version and will push to METADATA soon.
>
> On Wednesday, July 8, 2015 at 8:03:35 PM UTC-4, CasUpg wrote:
>>
>> Hi,
>> I'm trying SymPy to solve differential equations system but it does not
>> work in Julia. In Python it does. If I write the following in Python:
>>
>> from sympy import *
>> t = symbols('t')
>> x = Function('x')
>> y = Function('y')
>> eq = (Eq(diff(x(t),t), 12*t*x(t) + 8*y(t)), Eq(diff(y(t),t), 21*x(t) + 7*
>> t*y(t)))
>> dsolve(eq)
>>
>> it returns:
>>
>> [x(t) == C1*x0 + C2*x0*Integral(8*exp(Integral(7*t, t))*exp(Integral(12*t
>> , t))/x0**2, t),
>> y(t) == C1*y0 + C2(y0*Integral(8*exp(Integral(7*t, t))*exp(Integral(12*t
>> , t))/x0**2, t) + exp(Integral(7*t, t))*exp(Integral(12*t, t))/x0)]
>>
>>
>> But if I type the following in Julia:
>>
>> julia> versioninfo()
>> Julia Version 0.3.10
>> Commit c8ceeef (2015-06-24 13:54 UTC)
>> Platform Info:
>> System: Linux (i686-linux-gnu)
>> CPU: Intel(R) Celeron(R) CPU B815 @ 1.60GHz
>> WORD_SIZE: 32
>> BLAS: libopenblas (NO_LAPACK NO_LAPACKE DYNAMIC_ARCH NO_AFFINITY
>> Nehalem)
>> LAPACK: liblapack.so.3
>> LIBM: libopenlibm
>> LLVM: libLLVM-3.3
>>
>>
>> using SymPy
>> t, = @syms t
>> x, y = symbols("x, y", cls=SymFunction)
>> eq = [Eq(diff(x(t),t), 12*t*x(t) + 8*y(t)), Eq(diff(y(t),t), 21*x(t) + 7*
>> t*y(t))]
>> dsolve(eq)
>>
>> it returns:
>>
>> ERROR: `dsolve` has no method matching dsolve(::Array{Sym,1})
>>
>>
>> In the SymPy file math.jl, there is only the following definition for
>> dsolve:
>>
>> dsolve(ex::Sym, fx::Sym) = sympy_meth(:dsolve, ex, fx)
>>
>>
>>
>> How can I extend it in order to solve differential equations systems?
>>
>> A try can be found in:
>>
>> https://gist.github.com/Ismael-VC/2f39cd8cf30d19a78349
>>
>> but it returns a wrong answer.
>>
>
