c  **************************************************************
       subroutine cal_gyrat(n)

       implicit double precision(a-h, o-z)
       parameter(maxa=500,pi=3.1415926535d0,pi2=pi*2.d0)
    
       integer n
           common/matrix/x(maxa,3),bangle(maxa)
       common/figinfo/gyrat,endl2,zsum1,cmass(3),r1,shapef,writhe
  
        do j=1,3
	 cmass(j)=0
	enddo
	do i=1,n
	 do j=1,3
	 cmass(j)=cmass(j)+x(i,j)
	 enddo
	enddo
	do j=1,3
           cmass(j)=cmass(j)/n
	enddo

	gyrat=0.d0
	do i=1,n
	 do j=1,3
	 gyrat=gyrat+(x(i,j)-cmass(j))**2
	 enddo
	enddo
	gyrat=dsqrt(gyrat/n)	

       return
       end