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DOUBLE PRECISION FUNCTION FENORM (N,X)
C
C*****************************************************************
C *
C Determining the euclidean norm of a vector X. *
C *
C *
C INPUT PARAMETERS: *
C ================= *
C X : N-vector X(1:N); vector for which the euclidean norm *
C is to be determined *
C N : size of the vector X *
C *
C *
C OUTPUT PARAMETER: *
C ================= *
C FENORM : euclidean norm of the vector X *
C *
C *
C LOCAL VARIABLES: *
C ================ *
C SCPROD : dot product of the vector X with itself *
C I : iteration variable *
C *
C----------------------------------------------------------------*
C *
C subroutines required: none *
C *
C*****************************************************************
C *
C author : Thomas Eul *
C date : 05.03.1985 *
C source : FORTRAN 77 *
C *
C*****************************************************************
IMPLICIT DOUBLE PRECISION (A-H,O-Z)
C
C Input declarations
C
INTEGER N
DOUBLE PRECISION X(N)
C
C local variables
C
DOUBLE PRECISION SCPROD
INTEGER I
C
SCPROD = 0.0D0
FENORM = 0.0D0
DO 10 I = 1,N
SCPROD = SCPROD + X(I)*X(I)
10 CONTINUE
FENORM = DSQRT(SCPROD)
C
RETURN
END
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