photon use
  ext
  p0
 
  x0
 
  msg the starting grid
  gr y m
  gr z 1
  gr z m
  vec z 1 sh
  vec z 2 sh
  vec z 3 sh
  vec z 4 sh
  vec z 5 sh
  vec z 6 sh
  msg press RETURN to continue
  pause
  ext
  p2
 
  x2
 
  msg the end of the second time step
  gr y m
  gr z 1
  gr z m
  vec z 1 sh
  vec z 2 sh
  vec z 3 sh
  vec z 4 sh
  vec z 5 sh
  vec z 6 sh
  msg press RETURN to continue
  pause
  ext
  p5
 
  x5
 
  gr y m
  msg the end of the fifth time step
  gr z 1
  gr z m
  vec z 1 m sh
  red
  msg press RETURN to continue
  pause;vec off
  view z
  msg w1 contours near outlet
  con w1 z 5 fi;0.001
  pause;con off
  msg the view from the side
  view x
  pause
  msg pressure contours and vectors
  con p1 ix 4  fi;0.001
  con p1 ix 10 fi;0.001
  vec x ix 4;vec ix 10
 
  ENDUSE
  DISPLAY
  Coding in GXBFGR is accessed, and caused to create a cylindrical
  grid, which may be distorted at the start, and during time, in
  various ways.
 
  Fluid within it can be squeezed out; or fluid can be sucked in
  from the outside, according to the parameter settings.
 
  ENDDIS
    GROUP 1. Run title and other preliminaries
TEXT(cylinder with grid distortion   :B967
    GROUP 2. Transience; time-step specification
STEADY=F;LSTEP=5;GRDPWR(T,LSTEP,10.0,1.0)
    GROUP 3, 4, 5. X-, Y-, Z-direction grid specifications
NX=12; xulast=1.0; ny=6; yvlast=1.0; nz=6; zwlast=1.0
XCYIZ(1,NZ,T)
    GROUP 6. Body-fitted coordinates or grid distortion
char(movebfc);movebfc=$B005
#movebfc
    GROUP 7. Variables stored, solved & named
#solvel
    GROUP 9. Properties of the medium (or media)
REAL(GAMA);GAMA=1.0
RHO1=COMPRESS;RHO1B=1./GAMA;PRESS0=1.E5;RHO1A=1./PRESS0**GAMA
DRH1DP=COMPRESS;ENUL=1.0
    GROUP 11. Initialization of variable or porosity fields
FIINIT(P1)=0.0;FIINIT(U1)=0.0;FIINIT(V1)=0.0;FIINIT(W1)=0.0
    GROUP 13. Boundary conditions and special sources
PATCH(EXIT,HIGH,1,NX,1,NY/2,NZ,NZ,1,LSTEP); COVAL(EXIT,P1,0.1,0.0)
PATCH(INWALL,SWALL,1,NX,1,1,1,NZ,1,LSTEP); COVAL(INWALL,W1,1.0,0.0)
PATCH(OUTWALL,NWALL,1,NX,NY,NY,1,NZ,1,LSTEP)
COVAL(OUTWALL,W1,1.0,0.0)
    GROUP 15. Termination of sweeps
SELREF=T;RESFAC=1;LSWEEP=20
    GROUP 16. Termination of iterations
LITER(P1)=20
    GROUP 17. Under-relaxation devices
RELAX(U1,FALSDT,0.1);RELAX(V1,FALSDT,0.1);RELAX(W1,FALSDT,0.1)
RELAX(P1,LINRLX,0.5)
 
    GROUP 19. Data communicated by satellite to GROUND
SPEDAT(GRIDS, CASE,  C, CYLINDER)
SPEDAT(GRIDS, RADIN0, R, 0.0)
SPEDAT(GRIDS, RADOUT, R, 0.05)
SPEDAT(GRIDS, ZLENGT, R, 0.1)
SPEDAT(GRIDS, XAXFAC, R, 1.0)
SPEDAT(GRIDS, YAXFAC, R, 1.0)
SPEDAT(GRIDS, ZPOWER, R, 0.0)
 
SPEDAT(GRIDS, TMFCRI, R, 1.0)
SPEDAT(GRIDS, TMFCRO, R, 0.95)
SPEDAT(GRIDS, TMFCZL, R, 0.8)
SPEDAT(GRIDS, TMFCXF, R, 1.0)
SPEDAT(GRIDS, TMFCYZ, R, 1.0)
SPEDAT(GRIDS, TMFCZP, R, 1.0)
 
SPEDAT(GRIDS, ECCFAC, R, 0.0)
SPEDAT(GRIDS, DRDZ  , R, 0.0)
SPEDAT(GRIDS, GAPFAC, R, 0.0)
SPEDAT(SET,GXMONI,TRANSIENT,L,F) 
    GROUP 22. Spot-value print-out
TSTSWP=-1;IXMON=NX/2;IYMON=NY/2;IZMON=NZ/2
    GROUP 23. Field print-out and plot control
NPLT=1;NTPRIN=1;CSG1=PHI;CSG2=XYZ;IDISPA=1;IDISPB=1;IDISPC=LSTEP
IPLTF=3;XZPR=T;NXPRIN=NX/2;NPRINT=1;ISWPRF=LSWEEP-1
ISWPRF=LSWEEP-3