How to assign values to matrix in fortran90

[MI84]

Hi everyone. I'm new to Fortran. I wrote a code that contains a 2 * 2 matrix. Its elements are as follows: MATRIX (1,1) = ENERGY - eB MATRIX (1,2) = ek1 MATRIX (2,1) = ek2 MATRIX (2,2) = ENERGY - eA Now I want to assign the values I mentioned above to the matrix with the RESHAPE command. But the compiler shows the following error: error # 6366: The shapes of the array expressions do not conform Please guide me in solving this case. thank you.

PROGRAM DOS2

IMPLICIT NONE

INTEGER :: omega=1 ,k ,w ,Nc=1000 ,Ne=1000 ,M ,L

INTEGER, PARAMETER :: N=2

REAL :: eta=0.0015 ,ek ,kx ,t0=0.25 ,a0=1.0 ,DENSITY ,dE=0.001 ,eA ,eB ,X ,REALENERGY

DOUBLE PRECISION :: pi=4*ATAN(1.0)

COMPLEX , PARAMETER :: i=(0.0,1)
COMPLEX :: ENERGY ,C
COMPLEX :: ek1 ,ek2
COMPLEX,DIMENSION(N,N) :: MATRIX
COMPLEX,DIMENSION(N,N) :: INVERSE_MATRIX
COMPLEX :: GREEN
COMPLEX :: GREENFUNC

OPEN(2,FILE='DENSITY.txt')
OPEN(1,FILE='REALENERGY.txt')

DO w=-Ne,Ne

ENERGY=w*dE+i*eta
X=REAL(ENERGY)
REALENERGY =X/t0

WRITE(1,*) REALENERGY

GREENFUNC=(0,0)

DO k=-Nc,+Nc

kx=(pi*k)/(1000*a0)
ek1=t0*(1+EXP((-2)*i*kx*a0))
ek2=t0*(1+EXP(2*i*kx*a0))

eA=0.5*t0
eB=(- 0.5)*t0
DO M=1,N
DO L=1,N

MATRIX(M,N)=RESHAPE((/ (ENERGY-eB),ek2,ek1,(ENERGY-eA) /),(/ M,L /))

C=1.0/(((((X-eA)+i*eta)*((X-eB)+i*eta))/t0)-(ek1*ek2))
INVERSE_MATRIX(M,L)=C*(MATRIX(M,L))

GREEN=INVERSE_MATRIX(1,1)+INVERSE_MATRIX(2,2)
GREENFUNC=GREENFUNC+GREEN
END DO
END DO
END DO

GREENFUNC=GREENFUNC/(2*Nc+1)

DENSITY=DBLE(GREENFUNC*i) / (pi*omega)

WRITE(2,*) DENSITY

END DO

CLOSE(1)
CLOSE(2)

END PROGRAM DOS2

[jimdempseyatthecove]

>>MATRIX(M,N)=RESHAPE((/ (ENERGY-eB),ek2,ek1,(ENERGY-eA) /),(/ M,L /))

MATRIX(M,N) is a scalar (a single cell in array MATRIX), the result of the RESHAPE is an array.

Jim Dempsey

[MI84]

Thank you for your help. How can I assign those values to matrix elements? Is there a solution other than using the RESHAPE command?

[andrew_4619 · Accepted solution]

matrix = reshape( [a,b,c,d],[2,2] )

you are assigning the whole matrix in that command "[" is the same as the older "(/" BTW

[MI84]

Thank you for your help.