&DRIFT: XT-PLOT


DATASET

  Requests output of the x(t) relation to a dataset [no dataset is
  written by default].

dsname

  The dataset name. The name should be enclosed in single quotes if it
  contains any of the following: blank, comma, colon, double quote,
  equal sign. This means in practice that the quotes are required on
  a Vax for all dataset access outside the home disk. On VM/CMS, the
  blanks between file-name and file-type (and perhaps file-mode) may
  be replaced by dots, thus avoiding the need to add the quotes. On
  Unix systems, the name should be surrounded by double quotes so as
  to avoid case conversion of the file name.

member

  An identification string of at most 8 characters. This string is used
  by the various dataset commands and it is also needed if you keep
  more than one object (member) of the same type (cell, gas, track etc)
  in the same dataset.

remark

  A string of at most 29 characters that serves as a comment helping
  you to recognise a member in a dataset. The default remark for x(t)
  relations states the wire number and the angle.

angle

  The angle of the lines over which the drift time is minimised,
  measured with respect to the y-axis. The accuracy of the calculations
  becomes less when this angle becomes large.

  [Default: 0 degrees.]

xmin-xmax

  The range in x to be covered by the x(t) relation.

  [By default the whole x-range of the drift area is taken.]

xstep

  The distance between successive x points for which a corresponding
  minimal drift time is computed.

  [By default chosen such that the step size is a reasonable number
  for about 20 data points.]

jump

  The number of points between two accurately calculated points. The
  drift times for the intermediate points are obtained by interpolating
  the minimising drift line from the adjacent points, a procedure that
  is slightly less accurate than full drift line calculation.

  [By default, no point is interpolated.]

itermax

  The maximum number of iterations allowed.

  [Default: 5.]

eps

  An accuracy parameter, to be adjusted with great care.

  [Default: 1E-4.]

angle_range

  To save CPU time whilst gaining precision, it sometimes makes
  sense to explore only a limited angular range as seen from the
  target sense wire.

  This option should be used with great caution if a magnetic
  field is present since the drift lines in this case normally
  approach the wire at a (substantial) angle.

  [The default range is +90 to -90 degrees both left and right.]

PRINT-XT-RELATION

  Requests a printout of the x(t) relation.

  [On by default.]

PLOT-XT-RELATION

  Requests a graph of the x(t) relation.

  [On by default.]

SCALE

  Can be used to force a vertical scale in the x(t) relation plot,
  e.g. when you wish to overlay several of them.

Keyword index. Formatted on 10/11/98.