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piscal/dataassim/math/othersupmath/vectorrotation.f
2016-02-03 18:52:05 +00:00

16 lines
534 B
FortranFixed

subroutine vectorrotation(vectold,tranmatrix,vectnew)
implicit none
!transform the three components of a vector from an old coordinate
!system to an new coordinate system defined by the rotation matrix tranmatrix
!tranmatrix(i,j): ith row, jth column
double precision vectold(3),tranmatrix(3,3),vectnew(3)
integer i,j
do i=1,3
vectnew(i)=0.0d0
do j=1,3
vectnew(i)=vectnew(i)+
& tranmatrix(i,j)*vectold(j)
enddo
enddo
end subroutine vectorrotation