fd2d_prb.f

是一个接收永磁体磁场计算的程序

	subroutine u_init ( alpha, beta, gamma, delta, m, n, x, y, u0 )

!*****************************************************************************80
!
!! U_INIT supplies the initial value of U at each node.
!
!  Modified:
!
!    01 August 2004
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input, real ( kind = 8 ) ALPHA, BETA, GAMMA, DELTA, the parameters.
!
!    Input, integer M, N, the number of rows and columns.
!
!    Input, real ( kind = 8 ) X(M,N), Y(M,N), the X and Y coordinates
!    of the nodes.
!
!    Output, real ( kind = 8 ) U0(M,N), the initial value of U at the nodes.
!
	implicit none

	 integer m
	 integer n

	 real ( kind = 8 ) alpha
	 real ( kind = 8 ) beta
	 real ( kind = 8 ) delta
	 real ( kind = 8 ) gamma
	 real ( kind = 8 ) u0(m,n)
	 real ( kind = 8 ) ustar
	 real ( kind = 8 ) x(m,n)
	 real ( kind = 8 ) y(m,n)

	 ustar = gamma * alpha / ( beta - gamma )
	
	 u0(1:m,1:n) = ustar - 2.0D-07 
     &	  * ( x(1:m,1:n) - 0.1D+00 * y(1:m,1:n) - 225.0D+00 ) 
     &	  * ( x(1:m,1:n) - 0.1D+00 * y(1:m,1:n) - 675.0D+00 )

	 return
	end
	subroutine v_init ( alpha, beta, gamma, delta, m, n, x, y, v0 )

!*****************************************************************************80
!
!! V_INIT supplies the initial value of U at each node.
!
!  Modified:
!
!    30 November 2004
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input, real ( kind = 8 ) ALPHA, BETA, GAMMA, DELTA, the parameters.
!
!    Input, integer M, N, the number of rows and columns.
!
!    Input, real ( kind = 8 ) X(M,N), Y(M,N), the X and Y coordinates
!    of the nodes.
!
!    Output, real ( kind = 8 ) V0(M,N), the initial value of U at the nodes.
!
	 implicit none

	 integer m
	 integer n

	 real ( kind = 8 ) alpha
	 real ( kind = 8 ) beta
	 real ( kind = 8 ) delta
	 real ( kind = 8 ) gamma
	 real ( kind = 8 ) ustar
	 real ( kind = 8 ) v0(m,n)
	 real ( kind = 8 ) vstar
	 real ( kind = 8 ) x(m,n)
	 real ( kind = 8 ) y(m,n)

	 ustar = gamma * alpha / ( beta - gamma )
	 vstar = ( 1.0D+00 - ustar ) * ( alpha + ustar )

	 v0(1:m,1:n) = vstar - 3.0D-05 * ( x(1:m,1:n) - 450.0D+00 ) 
     &	  - 1.2D-04 * ( y(1:m,1:n) - 150.0D+00 )

	 return
	end