### ### We define the borders of the computational volume, ### we define the default mesh-spacing, ### and we define the conditions at the borders: ### -mesh spacing= InnerRadius/15 pxlow= -1.1*OuterRadius pylow= -1.1*OuterRadius pzlow = -(GapLength/2+TaperLength+9e-2) pxhigh= 1.1*OuterRadius pyhigh= 1.1*OuterRadius pzhigh= (GapLength/2+TaperLength+9e-2) # # The conditions to use at the borders of the computational volume: # cxlow= electric, cxhigh= electric cylow= electric, cyhigh= electric czlow= electric, czhigh= electricFor the linecharge, we have to specify its total charge, its length, and the (x,y)-position where it shall travel. We also have to say that we do not want to compute eigenvalues, but we want to perform a time domain computation. We specify that at the lower and upper z-planes absorbing boundary conditions shall be applied. In the section
-time
, we specify that we want to have saved
the fields at 10 equidistant times between the time that the line charge
has traveled 0.1 m and it has traveled 1 m.
We edit our inputfile, such that the end of it looks as:
-eigenvalues solutions= 15 estimation= 2e9 # the estimated highest frequency # doit -fdtd -lcharge charge= 1e-12 sigma= 4*STPSZE xposition= 0, yposition= 0 shigh= 1.5 showdata= yes -ports name= beamlow , plane= zlow, modes= 3, npml= 40, doit name= beamhigh, plane= zhigh, modes= 3, npml= 40, doit -time firstsaved= 0.1/@clight lastsaved= 1/@clight distancesaved= 0.1/@clight -fdtd doitThe so edited inputfile can be found as /usr/local/gd1/Tutorial-SRRC/wPlunger-wake.gdf. When we feed gd1 with the edited inputfile,
gd1 < wPlunger-wake.gdfgd1 stops and complains
# was: " call InnerPlunger( (OuterRadius-position1), 17 )" gbor> gbor> *** rnum: Bad Constant: starts here: "position1) " evaluate me(:lenEvaluate): "(231.15e-3-position1) " *** Status: "Bad factor :"p"" *** : "(231.15e-3-position1) " | *** Since this not seems to be an interactive session, *** I decide to treat this as a fatal error. *** Fix the input. stopWe did not specify what the value of the symbols
position1
and
position2
shall be.
We do this by defining them on the commandline of gd1:
gd1 -Dposition1=50e-3 -Dposition2=0 < wPlunger-wake.gdfNow the computation runs. After some minutes, the last words of gd1 are:
timestep= 900, simulated time= 6.9214e-9 s wakepotentials are known up to s= 1.3455 m cpu time/sec: used: 300.13, since last call: 31.23, MFLOPs/s: 82.67 Wall clock time: 305.99 s, MFLOPs/s: 81.09 The highest simulation time is reached .., I am stopping ################################ # cpu-seconds for FDTD : 320 # start date : 30/11/2002 # end date : 30/11/2002 # start time : 22:25:31 # end time : 22:33:22 ## This is the normal end. Don't worry. ## Start the postprocessor to look at the results. stop FDTDLoop