c
c ------------------------------------------------
c
	subroutine rodcomATB(r1,r2,rout)
c
c  combines two rotations as Rodrigues vectors
c  ROUT= R1+R2- R1 cross R2 / 1 - (R1dotR2)
c  except use the transpose of first rotation
c
	real r1(3),r2(3),rout(3)
	real dot,cross(3)
	call vecneg(r1)
	dot=1.-scalar(r1,r2)
	call vecpro2(r1,r2,cross)
	if(abs(dot).gt.1e-5) then
		rout(1)=(r1(1)+r2(1)-cross(1))/dot
		rout(2)=(r1(2)+r2(2)-cross(2))/dot
		rout(3)=(r1(3)+r2(3)-cross(3))/dot
	else
		rout(1)=1e38
		rout(2)=1e38
		rout(3)=1e38
		write(*,*) 'warning: RODCOM ->infinite result'
	endif
	return
	end
c
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c