-fdtd/-fexport: ASCII export of selected fields at selected times

During a time domain computation (with a static mesh, ienot windowwake), the fields can be stored at selected times.

 ##############################################################################
 # Flags: nomenu, noprompt, nomessage,                                        #
 ##############################################################################
 # section: -fexport                                                          #
 ##############################################################################
 # outfile= noname-0001
 # whattosave= e                        -- e-fields, h-fields                 #
 # firstsaved   = undefined                                                   #
 # lastsaved    = undefined                                                   #
 # distancesaved= undefined                                                   #
 # bbxlow  =    -1.0000e+30, bbylow =    -1.0000e+30, bbzlow =    -1.0000e+30 #
 # bbxhigh =     1.0000e+30, bbyhigh=     1.0000e+30, bbzhigh=     1.0000e+30 #
 ##############################################################################
 # doit, ?, return, end, help                                                 #
 ##############################################################################

• outfile:
  the basename of the files to write.
• whattosave:
  Specifies what field shall be exported to file.
• firstsaved, lastsaved, distancesaved:
  The first, last time to store the field, and the distance between the times when the field shall be stored.
• bbxlow=,bbxhigh=,bbylow=bbyhigh=,bbzlow=,bbzhigh=:
  Specifies the coordinates of a bounding box. Only the fields that lie within the box are written.
• outfile=:
  The name of the file to write the field values to.
• doit:
  While the time domain computation is running, the exportfiles are written. The format of the result files should be self-explanatory.

Example The following inputfile is for performing a wakepotential computation with a moving mesh window. During the time domain computation, the magnetic fields on the boundaries shall be exported as ascii files.

 define(STPF, 0.5)
 define(NP, 4)
 define(RADIUS, 1+1)
 define(GAP, 0.5)
 define(PERIODE, 0.6)
 define(BEAMR, RADIUS/2)
 define(STPSZE, SIGMA/10/STPF)

 define(DRADIUS, 2*STPSZE )
 define( ZLOW, -(NP*PERIODE+BEAMR)/2 )
 define( ZHIGH, (NP*PERIODE+BEAMR)/2 )
 -general
    outfile= /tmp/UserName/resultfile
    scratch= /tmp/UserName/scratch

 -mesh
    pxlow= -(RADIUS+DRADIUS), pxhigh= (RADIUS+DRADIUS)
    pylow= -(RADIUS+DRADIUS), pyhigh= (RADIUS+DRADIUS)
    pzlow= ZLOW, pzhigh= ZHIGH
 define(PZLOW, ZLOW)
 define(PZHIGH, ZHIGH)

   pxlow= 0, cxlow= mag
   pylow= 0, cylow= mag
   spacing= STPSZE

 ############
 ############
 -brick, material 1, volume (-INF, INF, -INF, INF, -INF, INF), doit

 do ip= -(NP-1)/2, (NP-1)/2, 1
    -gccylinder
       material= 0, radius= RADIUS, length= GAP
       origin= (0,0,ip*PERIODE-GAP/2)
       direction= (0,0,1)
 show= later
       doit
 enddo

 -gccylinder
    material= 0, radius= BEAMR, length= INF
    origin= ( 0, 0, -INF/2 ), direction= ( 0, 0, 1 )
# show= all
    doit

 #####
 -volumeplot, scale 1.8, plotopts -geometry 600x550+10+10, doit

 ####
  -lcharge
    sigma= 0.1, charge= 1e-12, xposition= 0, yposition= 0
    #
    # The following large value for shigh is chosen for getting a movie of the
    # full structure.
    # 
    shigh= ZHIGH-ZLOW

   define(NDT, 0.5 * SIGMA / @clight)
 -fexport
    outfile= /tmp/UserName/H-onmat-
    what= honmat
    firstsaved= 1e-20, lastsaved= 1e20
    distancesaved= NDT
    bbxlow= 0, bbxhigh= INF
    bbylow= 0, bbyhigh= INF
    bbzlow= PZLOW+2*STPSZE, bbzhigh= PZHIGH-2*STPSZE
    doit

 -windowwake,
     doit
 end
#####################

The following is input for gd1.pp to read the files and create many gifs from them. From the gifs, a mpeg file is created and displayed.

# Input for gd1.pp:

 -3dmanygifs
   1stinfile= /tmp/UserName/H-onmat--000000001.gz
   outfiles= /tmp/UserName/absh-
## uptonfiles= 10
#   what= abs
   what= logabs
   uptonfiles= 1e9
   xrot= -30, yrot= 40
   doit

 system( mpeg_encode ./gdfidl.3dmanygifs-mpeg_encode-params )
 system( mpeg_play -dither color fexported.mpg )