&SIGNAL: PLOT-FIELD


functions

  All functions in the description of the PLOT command (f1, f2 ... f6)
  may depend on the following set of variables:

  ------------------------------------------------------------------------
  Symbol            Meaning                     Note
  ------------------------------------------------------------------------
  X, Y, Z           Position                    R, PHI for polar cells
  EX, EY, EZ, E     E-field at (x,y,z)          ER, EPHI for polar cells
  EWX, EWY, EWZ, EW Weighting at (x,y,z)        EWR, EWPHI for polar cells
  BX, BY, BZ, B     B-field at (x,y,z)          only if there is a B-field
  VDX, VDY, VDZ, VD Local e- drift velocity     VDR, VDPHI for polar cells
  TIME_E            Drift time for electrons
  TIME_ION          Drift time for ions
  STATUS_E          Drift status for electrons  a number, not a string
  STATUS_ION        Drift status for ions       a number, not a string
  Q_E               Charge induced by an e-
  Q_ION             Charge induced by an ion
  ------------------------------------------------------------------------

  Other variables can be added on request.

Additional Information on:

  • charges
  • status_code
  • times
  • weighting_field

  • contour

      Produces a plot of the lines of equal function values. The contours
      are labeled with the function value if the LABEL option is on (which
      is by default the case).
    
      The function is computed on the part of the viewing plane that is
      located within the current AREA box.
    
      If you request AUTOMATIC scaling of the range, contours are drawn
      at decent function heights covering the range of the function on the
      AREA. The number of contours is used to compute a rough distance
      between two contours; the distance is rounded downwards. The number
      of contours actually drawn may therefore be larger than the number
      you request.
    
      [The default function is Q_E, the charge induced on the read-out
      electrode by an electron drifting from (x,y,z). The contour range
      is by default adjusted automatically. By default, about 20 contours
      are plotted.]
    

    graph

      The function is evaluated on the track or on the curve specified
      with the ON keyword.
    
      The geometric aspects of the track, if used, should be set by means
      of the TRACK command before calling PLOT. Other aspects of the track,
      such as the clustering model, are not used in the present context.
    
      A curve should be parametrised in terms of T which will run from 0
      to 1. All 3 coordinates of the curve should be specified. Note that
      ON expects only one argument, the parametrisation should therefore
      be enclosed in quotes, e.g. 'cos(pi*t),sin(pi*t),0' would be
      appropriate to describe a semi-circle in the z=0 plane.
    
      The SCALE option can be used to force a vertical scale in the
      plot, this can for instance be useful if you intend to overlay
      various graphs.
    
      If you select the PRINT option, then the values plotted in the
      graph will also be printed out. Output re-routing (> file) can
      be used to write the values to a file.
    
      The number of sampling points can be set with N.
    
      [The default function is Q_E, the charge induced on the read
      out electrode by an electron drifting from (x,y,z). The default
      number of sampling points is MXLIST, 200 or 1000 depending on
      the compilation parameters.]
    

    histogram

      The function is sampled at GRID by GRID points on the part of
      the current viewing plane that is located inside the AREA box.
      The function values are entered in an histogram.
    
      This kind of plot can be useful to estimate for instance the
      spread in drift time over a given region.
    
      The automatic search for proper binning (AUTOMATIC) uses the
      first few entries to set the range. Since the grid is scanned
      in a regular sequence, these entries are not necessarily
      representative for the entire sample, in particular if the
      number of bins is small compared to the grid size. See CALL ->
      BOOK_HISTOGRAM -> options -> AUTOMATIC for details on the
      automatic binning procedure.
    
      [The default function is Q_E, the charge induced on the read
      out electrode by an electron drifting from (x,y,z). The default
      preset to 100 and the range is by default chosen automatically.]
    

    surface

      The function is sampled at GRID by GRID points on the part of
      the current viewing plane that is located inside the AREA box.
      The function values are presented as a three dimensional plot.
      The plot is first rotated by phi degrees around the z-axis and
      then tilted by theta degrees from the z-axis.
    
      This plot is decorative but it is generally agreed upon that it is
      hard to extract any meaningful information from it ...
    
      [The default function is Q_E, the charge induced on the read
      out electrode by an electron drifting from (x,y,z). The default
      viewing angles are 30 and 60 degrees.]
    

    vector

      This plot shows the flow of a 3-vector sampled at GRID by GRID
      points on the part of the current viewing plane that is located
      inside the AREA box. The vectors are displayed like geometrical
      objects.
    
      The z-component is set to 0, if not explicitely specified. For
      other than (x,y) views, this may give incorrect impressions.
    
      It is advisable to have roughly equal ranges in view of the scaling
      that is performed on the vectors.
    
      [The default functions are EWX, EWY, EWZ, i.e. the weighting field.]
    

    sense

      The number of the sense wire group for which you wish to
      have the field plotted. This number can be found in the
      output of the SELECT command without arguments.
    
      By default, all sense wire groups are plotted.
    

    wire

      The number of any wire of the sense wire group for which
      you wish to have the field plotted. These numbers can be
      found in the output that is produced in response to the
      CELL-PRINT option of the cell section, and of the PRINT-CELL
      command in the optimisation section.
    

    copy

      Since the induced currents are not the same for all copies
      of periodic cells, a separate field can be computed for each
      such copy.
    
      Accurate results for other copies than the basic one are
      non-trivial to obtain in periodic cells. See also the
      FOURIER instruction.
    
      By default, the basic cell is assumed.
    

    Keyword index. Formatted on 10/11/98.