Three-dimensional line of magnetic force starting from equatorial plane
subroutine ainte21(ia,aa,f,p)

Description: This program draws three-dimensional line of magnetic force starting from equatorial plane using magnetic field data of 3 components from three-dimensional MHD simulation data f(i1).

Input variable:
      nx=ia(1) : Data number of the x direction in the starting point of line of magnetic force
      ny=ia(2) : Data number of the y direction in the starting point of line of magnetic force
      mx=ia(3) : Data number of the x direction of three-dimensional data f(i1)
      my=ia(4) : Data number of the y direction of three-dimensional data f(i1)
      mz=ia(5) : Data number of the z direction of three-dimensional data f(i1)
      nxz=ia(6) : The parameter which adjusts the global center
      mi=ia(7) : The first position of the input variable
      mo=ia(8) : The first position of the output variable
      th0=aa(1)*pi/180.0 : The lowest latitude in the starting point of line of magnetic force
      aru=aa(2) : The parameter which characterizes the transition of the inner edge
      ar1=aa(3) : The outside edge radius of the transition region of inner edge
      arb=aa(4) : The edge radius within the transition region of inner edge
      xxl=aa(5) : The length of simulation box of the x direction
      yyl=aa(6) : The length of simulation box of the y direction
      zzl=aa(7) : The length of simulation box of the z direction
      b0=aa(8) : The size of the dipole magnetic field ( generally  1.0 )
      gx0=aa(13) : The x coordinate of the origin which describes the graph
      gy0=aa(14) : The y coordinate of the origin which describes the graph
      gxl=aa(15) : The length of x direction which describes the graph
      gyl=aa(16) : The length of y direction which describes the graph
      gth=aa(17)*pi/180.0 : The rotation angle of the coordinate of the graph
      gxmi=aa(18) : The minimum value of x direction which describes the graph
      gxma=aa(19) : The maximum value of x direction which describes the graph
      ep1=aa(20) : The minimum threshold of decision in length of field line
      xlim=aa(23) : The restriction of the minimum value of the x coordinate
      xli2=aa(24) : The restriction of the minimum value of the y,z coordinate

Main using subroutine:
      quant1(x,y,z,hx,hy,hz,1,mx,my,mz,nxp,aa,f,q) :
        MHD data q(8) of optional place (x,y,z) is calculated from MHD data f(i1) 
        of the three-dimensional lattice point
      linebe(r,g,b) : The start of the polygonal line description
      linep2(x1,y2,z1,1,lasl) : The execution of the polygonal line description
      lineen(lasl) : The end of the polygonal line description