问题描述
我在,我尝试找出如何生成与我需要坚持的特定形式相对应的Fortran代码。所需的FORTRAN代码如下所示():
Building on a former example that I've found here, I try to find out how to generate a Fortran code that correspond to a specific form that I need to stick to. The required FORTRAN code will look like this (it is based on the FitzHugh–Nagumo model):
SUBROUTINE FF(NE,U,PAR,F)
! ---------- --
! Define the nonlinear term
IMPLICIT NONE
INTEGER, INTENT(IN) :: NE
DOUBLE PRECISION, INTENT(IN) :: U(NE),PAR(*)
DOUBLE PRECISION, INTENT(OUT) :: F(NE)
DOUBLE PRECISION u,v,e,a1,a0
u=U(1)
v=U(2)
e=PAR(1)
a1=PAR(2)
a0=PAR(3)
F(1)= u-u**3-v
F(2)= e*(u-a1*v-a0)
END SUBROUTINE FF
我设法在SymPy中创建正确的表达式,但是我还没有弄清楚如何使用 codegen 。到目前为止,这是我的尝试:
I manage to create the right expressions in SymPy, but I haven't figured out how to generate the required code with
codegen
. Here is my attempt so far:
from sympy import symbols,latex
from sympy.utilities.codegen import codegen
from sympy.tensor import IndexedBase, Idx
from sympy import Matrix
U, PAR = symbols('U PAR', cls=IndexedBase)
u = U[1]
v = U[2]
e = PAR[1]
a1 = PAR[2]
a0 = PAR[3]
dudt = u-u**3-v
dvdt = e*(u-a1*v-a0)
print latex(dudt)
print latex(dvdt)
F = Matrix([dudt,dvdt])
print F
result = codegen(('my_function', F), 'f95', 'my_project')
print result[0][1]
但这给了我
IndexException:
Range is not defined for all indices in: PAR[3]
推荐答案
如果只需要在python代码中调用FORTRAN函数,我发现使用FORTRAN包装器是比尝试在python中重新创建FORTRAN代码简单得多,尤其是在GOTO的情况下
If you simply need to call the FORTRAN function within your python code, I found that using a FORTRAN wrapper was much simpler than trying to recreate FORTRAN code in python, especially if GOTO's are heavily used.
您尝试过f2py吗?
Have you tried f2py? https://sysbio.ioc.ee/projects/f2py2e/
这篇关于使用SymPy码本为方程组生成Fortran子例程的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!