DNEQNF 算法求解非线性方程组

muzili2008

大家好，我采用DNEQNF求解非线性方程组，代码如下：

[Fortran] 纯文本查看 复制代码

C module function_equation
 C implicit none

 C contains
 subroutine FCN(xx,yy,nn)
 implicit none
 integer nn
 double precision xx(nn),yy(nn)
   
 yy(1) = xx(1)**2+xx(2)**2-5d0
 yy(2) = (xx(1)+1d0)*xx(2)-(3d0*xx(1)+1d0)
 return
 end subroutine
 C end module
 program main_test
 use imsl
 C use function_equation
 implicit none
 external FCN
 double precision , parameter :: errrel = 1d-7
 integer , parameter :: n = 2
 integer , parameter :: itmax = 200
 double precision x_guess,ans(2),fnorm
 x_guess = (1d0,1d0)
 call dneqnf(FCN,errrel,n,itmax,x_guess,ans,fnorm)
 print *, ans
 end 

如果希望将求解的方程封装在一个module里面，则出现错误。这样的问题应该怎么解决呢？
（上述代码去掉注释后 ，就将求解的函数封装在module里面了。）

muzili2008

楚香饭 发表于 2015-3-19 17:22
错误提示很重要，为什么每次都不给出？

你好 ，这个是提示信息。

D:\Fortran\Algorithm\nonliner_equation_03\main_test.for
D:\Fortran\Algorithm\nonliner_equation_03\main_test.for(22) : Error: The attributes of this name conflict with those made accessible by a USE statement.   [FCN]
external FCN
-----------------^
D:\Fortran\Algorithm\nonliner_equation_03\main_test.for(29) : Error: The characteristics of dummy argument 1 of the associated actual procedure differ from the characteristics of dummy argument 1 of the dummy procedure. (12.2)   [FCN]
call dneqnf(FCN,errrel,n,itmax,x_guess,ans,fnorm)
--------------------^
D:\Fortran\Algorithm\nonliner_equation_03\main_test.for(29) : Error: The characteristics of dummy argument 2 of the associated actual procedure differ from the characteristics of dummy argument 2 of the dummy procedure. (12.2)   [FCN]
call dneqnf(FCN,errrel,n,itmax,x_guess,ans,fnorm)
--------------------^
Error executing df.exe.

main_test.obj - 3 error(s), 0 warning(s)

非常感谢！！