[julia-users] Re: Differential equations system with SymPy function dsolve?

2015-07-09 Thread CasUpg 
Thank you very much!

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.

[julia-users] Re: Differential equations system with SymPy function dsolve?

2015-07-08 Thread Ismael VC 
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.

[julia-users] Re: Differential equations system with SymPy function dsolve?

2015-07-08 Thread j verzani 
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.

[julia-users] Re: Differential equations system with SymPy function dsolve?

2015-07-08 Thread j verzani 
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.