!Copyright (c) 2013 by tdem.org under guide of Xiu Li(lixiu@chd.edu.cn)
!written by Huaifeng Sun(sunhuaifeng@gmail.com) and Xushan Lu(luxushan@gmail.com)
!Code distribution @ tdem.org or sunhuaifeng.com

subroutine Get_pml_parameters
  use constantparameters
  USE PML_PARAMETER
  implicit none
  integer i,j,k,II,JJ,KK
		DO i = 1,PML_X1
			sig_PML_e_x1(i) = sig_x_max * ( (PML_X1 - i) / (PML_X1 - 1.0) )**ma
			alpha_PML_e_x1(i) = alpha_x_max*((i-1.0)/(PML_X1-1.0))**mb
			kappa_PML_e_x1(i) = 1.0+(kappa_x_max-1.0)*((PML_X1 - i) / (PML_X1 - 1.0))**ma
        ENDDO
		DO i = 1,PML_X1-1
			sig_PML_h_x1(i) = sig_x_max * ( (PML_X1 - i - 0.5)/(PML_X1-1.0))**ma
			alpha_PML_h_x1(i) = alpha_x_max*((i-0.5)/(PML_X1-1.0))**mb
			kappa_PML_h_x1(i) = 1.0+(kappa_x_max-1.0)*((PML_X1 - i - 0.5) / (PML_X1 - 1.0))**ma
		ENDDO
		DO i = 1,PML_X2
			sig_PML_e_x2(i) = sig_x_max * ( (PML_X2 - i) / (PML_X2 - 1.0) )**ma
			alpha_PML_e_x2(i) = alpha_x_max*((i-1.0)/(PML_X2-1.0))**mb
			kappa_PML_e_x2(i) = 1.0+(kappa_x_max-1.0)*((PML_X2 - i) / (PML_X2 - 1.0))**ma
		ENDDO
		DO i = 1,PML_X2-1
			sig_PML_h_x2(i) = sig_x_max * ( (PML_X2 - i - 0.5)/(PML_X2-1.0))**ma
			alpha_PML_h_x2(i) = alpha_x_max*((i-0.5)/(PML_X2-1.0))**mb
			kappa_PML_h_x2(i) = 1.0+(kappa_x_max-1.0)*((PML_X2 - i - 0.5) / (PML_X2 - 1.0))**ma
		ENDDO

        !*************************************************************************************************
        !y方向pml参数的求解
		DO j = 1,PML_Y1
			sig_PML_e_y1(j) = sig_y_max * ( (PML_Y1 - j ) / (PML_Y1 - 1.0) )**ma
			alpha_PML_e_y1(j) = alpha_y_max*((j-1)/(PML_Y1-1.0))**mb
			kappa_PML_e_y1(j) = 1.0+(kappa_y_max-1.0)*((PML_Y1 - j) / (PML_Y1 - 1.0))**ma
		ENDDO
		DO j = 1,PML_Y1-1
			sig_PML_h_y1(j) = sig_y_max * ( (PML_Y1 - j - 0.5)/(PML_Y1-1.0))**ma
			alpha_PML_h_y1(j) = alpha_y_max*((j-0.5)/(PML_Y1-1.0))**mb
			kappa_PML_h_y1(j) = 1.0+(kappa_y_max-1.0)*((PML_Y1 - j - 0.5) / (PML_Y1 - 1.0))**ma
		ENDDO
		DO j = 1,PML_Y2
			sig_PML_e_y2(j) = sig_y_max * ( (PML_Y2 - j ) / (PML_Y2 - 1.0) )**ma
			alpha_PML_e_y2(j) = alpha_y_max*((j-1)/(PML_Y2-1.0))**mb
			kappa_PML_e_y2(j) = 1.0+(kappa_y_max-1.0)*((PML_Y2 - j) / (PML_Y2 - 1.0))**ma
		ENDDO
		DO j = 1,PML_Y2-1
			sig_PML_h_y2(j) = sig_y_max * ( (PML_Y2 - j - 0.5)/(PML_Y2-1.0))**ma
			alpha_PML_h_y2(j) = alpha_y_max*((j-0.5)/(PML_Y2-1.0))**mb
			kappa_PML_h_y2(j) = 1.0+(kappa_y_max-1.0)*((PML_Y2 - j - 0.5) / (PML_Y2 - 1.0))**ma
		ENDDO

        !*************************************************************************************************
        !Z方向pml参数的求解
		DO k = 1,PML_Z1
			sig_PML_e_z1(k) = sig_z_max * ( (PML_Z1 - k ) / (PML_Z1 - 1.0) )**ma
			alpha_PML_e_z1(k) = alpha_z_max*((k-1)/(PML_Z1-1.0))**mb
			kappa_PML_e_z1(k) = 1.0+(kappa_z_max-1.0)*((PML_Z1 - k) / (PML_Z1 - 1.0))**ma
		ENDDO
		DO k = 1,PML_Z1-1
			sig_PML_h_z1(k) = sig_z_max * ( (PML_Z1 - k - 0.5)/(PML_Z1-1.0))**ma
			alpha_PML_h_z1(k) = alpha_z_max*((k-0.5)/(PML_Z1-1.0))**mb
			kappa_PML_h_z1(k) = 1.0+(kappa_z_max-1.0)*((PML_Z1 - k - 0.5) / (PML_Z1 - 1.0))**ma
		ENDDO
		DO k = 1,PML_Z2
			sig_PML_e_z2(k) = sig_z_max * ( (PML_Z2 - k ) / (PML_Z2 - 1.0) )**ma
			alpha_PML_e_z2(k) = alpha_z_max*((k-1)/(PML_Z2-1.0))**mb
			kappa_PML_e_z2(k) = 1.0+(kappa_z_max-1.0)*((PML_Z2 - k) / (PML_Z2 - 1.0))**ma
		ENDDO
		DO k = 1,PML_Z2-1
			sig_PML_h_z2(k) = sig_z_max * ( (PML_Z2 - k - 0.5)/(PML_Z2-1.0))**ma
			alpha_PML_h_z2(k) = alpha_z_max*((k-0.5)/(PML_Z2-1.0))**mb
			kappa_PML_h_z2(k) = 1.0+(kappa_z_max-1.0)*((PML_Z2 - k - 0.5) / (PML_Z2 - 1.0))**ma
        ENDDO

        !求解den
        !x方向
        ii =PML_X2
		DO i = 1,NX
			if (i <= PML_X1) then
				den_ex(i) = 1.0/kappa_PML_e_x1(i)
			elseif (i >= NX+2-PML_X2) then
				den_ex(i) = 1.0/kappa_PML_e_x2(ii)
				ii = ii-1
			else
				den_ex(i) = 1.0
			endif
		ENDDO
        ii =PML_X2-1
		DO i = 1,NX
			if (i <= PML_X1-1) then
				den_hx(i) = 1.0/kappa_PML_h_x1(i)
			elseif (i >= NX+2-PML_X2) then
				den_hx(i) = 1.0/kappa_PML_h_x2(ii)
				ii = ii-1
			else
				den_hx(i) = 1.0
			endif
        ENDDO
        !y方向
        jj = PML_Y2
		DO j = 1,NY
			if (j <= PML_Y1) then
				den_ey(j) = 1.0/kappa_PML_e_y1(j)
			elseif (j >= NY+2-PML_Y2) then
				den_ey(j) = 1.0/kappa_PML_e_y2(jj)
				jj = jj-1
			else
				den_ey(j) = 1.0
			endif
		ENDDO
		jj =PML_Y2-1
		DO j = 1,NY
			if (j <= PML_Y1-1) then
				den_hy(j) = 1.0/kappa_PML_h_y1(j)
			elseif (j >= NY+2-PML_Y2) then
				den_hy(j) = 1.0/kappa_PML_h_y2(jj)
				jj = jj-1
			else
				den_hy(j) = 1.0
			endif
        ENDDO
        !z方向
        kk =PML_Z2
		DO k = 1,NZ
			if (k <= PML_Z1) then
				den_ez(k) = 1.0/kappa_PML_e_z1(k)
			elseif (k >= NZ+2-PML_Z2) then
				den_ez(k) = 1.0/kappa_PML_e_z2(kk)
				kk = kk - 1
			else
				den_ez(k) = 1.0
			endif
		ENDDO
		kk =PML_Z2-1
		DO k = 1,NZ
			if (k <= PML_Z1-1) then
				den_hz(k) = 1.0/kappa_PML_h_z1(k)
			elseif (k >= NZ+2-PML_Z2) then
				den_hz(k) = 1.0/kappa_PML_h_z2(kk)
				kk = kk - 1
			else
				den_hz(k) = 1.0
			endif
		ENDDO

end subroutine Get_pml_parameters