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DZFFTM Routine Documentation

DZFFTM (M,N,X,COMM,INFO) SUBROUTINE
INTEGER M Input
On input: M is the number of sequences to be transformed.

INTEGER N Input
On input: N is the length of the real sequences in X

DOUBLE PRECISION X(N*M) Input/Output
On input: X contains the M real sequences of length N to be transformed. Element i of sequence j is stored in location i+(j-1)*N of X.
On output: X contains the transformed Hermitian sequences.

DOUBLE PRECISION COMM(3*N+100) Input/Output
COMM is a communication array. Some portions of the array are used to store initializations for subsequent calls with the same sequence length N. The remainder is used as temporary store.

INTEGER INFO Output
On output: INFO is an error indicator. On successful exit, INFO contains 0. If INFO = -i on exit, the i-th argument had an illegal value. 

     Example:
             CALL DZFFTM(1,N,X,COMM,INFO)
             CALL DZFFTM(2,N,X,COMM,INFO)
             DO 10 I = 1, N
                X(I,3) = X(I,1)*X(N-I+1,2)
        10   CONTINUE
             CALL ZDFFTM(1,N,X(1,3),COMM,INFO)