我想計算不同大小矩陣的特徵值和特徵向量。我正在使用一段非常簡單的Fortran90代碼,並且正在編譯鏈接到我的機器中提供的適用於英特爾MKL軟件包的Lapack庫,該機器在Ubuntu中運行。代碼「matrix_diag_01.f90」附在消息的末尾。 「隨機」模塊只包含Numerical Recipes中的「跑」隨機數發生器。代碼編譯得很好使用在Fortran中使用mkl lapack庫的特徵值和特徵向量
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
當給出小的矩陣時,可執行文件很好地工作。但是,對於大小爲3000x3000的矩陣,它會產生一些奇怪的行爲。首先它出現這個錯誤
MKL ERROR : Parameter 8 was incorrect on entry to SSYEVD
但是,在調用SSYEVD時只有3個參數。其次,它返回特徵向量,但不返回特徵值。我通過在另一臺具有更大內存的機器上編譯進行檢查,但結果是一樣的。
任何人都可以請幫忙嗎?
謝謝!
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
我沒有解決MKL錯誤,雖然沒有足夠的可用內存聽起來不可能。關於不返回的特徵值,你有沒有試過用'info'參數調用'ssyevd'? – eriktous