It is also a one-argument PIL command, for generating curvilinear (BFC) grid coordinates within the sub-domain specified by the DOMAIN command.
There are two options:
This method generates the grid very quickly, and when the boundary coordinates are smoothly varying it generates useful grids. When the boundaries exhibit discontinuous changes in direction, MAGIC(T) tends to propagate the discontinuities into the domain. In such circumstances, it may produce highly non-orthogonal, and hence undesirable, grids.
MAGIC(L) involves the solution of Laplace-like equations for the cartesian coordinates of the cell corners. The finite- difference equations solved for XC, YC and ZC are expressed in linearized form, so that they can be solved by means of linear- equation solvers. The non-linearities of the equations find their expression in the coefficients of the linearized equations, and consequently the coefficients require updating after each solution of the linearized system of equations.
The solution-control parameters LITXC, LITYC & LITZC set the number of iterations of the linear-equation solver for the coordinates XC, YC and ZC. The parameter MSWP sets the number of sweeps of the sub-domain, each sweep involving the update of the coefficients of the equations.
The progress to convergence of the iterative process can be monitored at the VDU at the location IMON, JMON and KMON. The linear solver can be over-relaxed by RELXC, RELYC, RELZC. Other parameters related to the use of MAGIC(L) are: LIJ, LJK, LIK, SLIDW, SLIDE, SLIDS, SLIDN, SLIDL, SLIDH, FIXCOR and FIXDOM.
The VIEW command permits the grid generated to be displayed.