使用DGESV的fortran线性方程组

Question

我是fortran的新手，正在尝试使用DGESV解决一组线性方程。我试图让最简单的程序只是为了让方法运行，但是收到此错误消息：

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0  0x106cef092
#1  0x106cee3b0
#2  0x7fff8dda9f19
Segmentation fault: 11

以下是代码：

   program linearEqSolver

   implicit none
   EXTERNAL         DGESV

   integer, parameter :: N = 3, NRHS = 1, LDA = N,LDB = N
   integer :: INFO
   real, dimension (N) :: IPIV, b
   real, dimension (N,N) :: A


   b = (/ 4, -6, 7/)
   A(:,1) = (/ 1, 1, -1/)
   A(:,2) = (/ 1, -2, 3/)
   A(:,3) = (/ 2, 3, 1/)

   CALL DGESV( N, NRHS, A, LDA, IPIV, B, LDB, INFO )

   end program