begin thorn EMScript

begin variables
    El_i B_i CEl CB rho
end variables

begin temporaries
  sigma
end temporaries

begin calculation EM_initial scheduled at initial
  sigma = 1
  El1 = sigma*cos(2*PI*(x + y))
  El2 = -1*(1 - sigma)*cos(2*PI*x) - sigma*cos(2*PI*(x + y))
  El3 = 0
  B1  = 0
  B2  = 0
  B3  = (1 - sigma)*cos(2*PI*x) + sigma*cos(2*PI*(x + y))
end calculation

begin calculation EM_evol scheduled at MoL_CalcRHS
  D_t El_a = Eps_abc * Euc^be * Euc^cf * D_e B_f
  D_t B_a  = -1*Eps_abc * Euc^be * Euc^cf * D_e El_f
end calculation

begin calculation EM_constraints scheduled at analysis
  CEl = D_b El_a * Euc^ab
  CB = D_b B_a * Euc^ab
end calculation

begin calculation EM_energy scheduled at analysis
  rho = Euc^ab * El_a * El_b/2 + Euc^ab * B_a * B_b/2
end calculation

end thorn