我正在尝试计算不同大小矩阵的特征值和特征向量。我正在使用一段非常简单的 Fortran90 代码,我正在编译它并链接到英特尔 MKL 包中包含的适当 Lapack 库,该库在我的机器中可用,它在 Ubuntu 中运行。代码“matrix_diag_01.f90”附在消息的末尾。“random”模块只包含来自 Numerical Recipes 的“ran”随机数生成器。代码使用编译良好
ifort -I $(MKLPATH) -o matrix_diag_01 matrix_diag_01.f90
random.f90 $(MKLPATH)libmkl_lapack95.a -Wl,--start-group
$(MKLPATH)libmkl_intel_lp64.a $(MKLPATH)libmkl_lapack.a
$(MKLPATH)libmkl_intel_thread.a $(MKLPATH)libmkl_core.a
-Wl,--end-group -lguide -lpthread
当给出较小的矩阵时,可执行文件可以很好地工作。但是,对于大小为 3000x3000 的矩阵,它会产生一些奇怪的行为。首先它给出了这个错误
MKL ERROR : Parameter 8 was incorrect on entry to SSYEVD
但是,对 SSYEVD 的调用中只有 3 个参数。其次,它返回特征向量但不返回特征值。我已经通过在另一台内存更大的机器上编译来检查,但结果是一样的。
有人可以帮忙吗?
谢谢!
PROGRAM matrix_diag_01
USE random
IMPLICIT NONE
INTERFACE
SUBROUTINE diag(mat,n)
INTEGER n
REAL,DIMENSION(n,n) :: mat
END SUBROUTINE
END INTERFACE
INTEGER n,i,j,iseed
REAL, DIMENSION(:), ALLOCATABLE :: w
REAL, DIMENSION(:,:), ALLOCATABLE :: mat
write (*,*) ' Please enter size of matrix'
read (*,*) n
write (*,*) ' Please type seed'
read (*,*) iseed
allocate (mat(n,n))
do i = 1,n
do j = 1,n
mat(i,j) = ran(iseed)
end do
end do
call diag(mat,n)
stop
END
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
SUBROUTINE diag(mat,n)
USE mkl95_lapack
USE mkl95_precision
IMPLICIT NONE
CHARACTER(len=1) :: jobz = 'V'
INTEGER n,i
REAL,DIMENSION(n,n) :: mat
REAL,DIMENSION(:,:),ALLOCATABLE :: matt,a
REAL,DIMENSION(:),ALLOCATABLE :: w
allocate (matt(n,n),a(n,n),w(n))
matt = mat*transpose(mat)
a = sqrt(matt)
open (unit=7,file="matrix.dat",status="unknown")
do i = 1,n
write (7,100) a(i,:)
end do
close (unit=7)
call syevd(a,w,jobz)
open (unit=8,file="eig_val.dat",status="unknown")
do i = 1,n
write (8,100) w(i)
end do
close (unit=8)
open (unit=9,file="eig_vec.dat",status="unknown")
do i = 1,n
write (9,100) a(i,:)
end do
close (unit=9)
return
100 format(5000f16.5)
end