subroutine  calc_A(A, q)

c------------------------------------------------------------
c  Calculates the jacobian matrix for the 
c  Burgers equation. Note that in this case
c  the matrix is just an scalar.
c------------------------------------------------------------

         implicit      none

         character*6   cdnm
         parameter   ( cdnm = 'calc_A' ) 

         logical       ltrace
         parameter   ( ltrace = .false. )

         real*8        A
         real*8        q
         
c============================================================
c============================================================

         if ( ltrace ) then
            write(0,*) cdnm,':     q = ', q
         endif
         A = q
         if ( ltrace ) then
            write(0,*) cdnm,':     A = ', A
         endif
         return
         end