&DRIFT: XT-PLOT
Requests output of the x(t) relation to a dataset [no dataset is
written by default].
Additional information on:
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\°.]
Forms together with xmax the range over
which the x(t) relation is computed.
[By default the whole x-range of the drift area is taken.]
Forms together with xmin the range over
which the x(t) relation is computed.
[By default the whole x-range of the drift area is taken.]
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.]
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.]
The maximum number of iterations allowed.
[Default: 5.]
An accuracy parameter, to be adjusted with great care.
[Default: 10\<SUP\>-4\</SUP\>.]
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\° both left and right.]
Requests a printout of the x(t) relation.
[On by default.]
Requests a graph of the x(t) relation.
The graph usually shows 2 curves:
- a curve plotted with representation
FUNCTION-1
which shows the minimum drift time that has been found;
- a curve plotted with representation
FUNCTION-2
which shows the integrated diffusion for the fastest drift-line.
Both curves are interrupted if the procedure has doubts about
the accuracy of a neighbouring point - markers are used if both
neighbours of a reliable point are considered unreliable.
[On by default.]
If this option is selected, then the x(t) relations that have been
obtained by XT-PLOT, will be stored as a set of matrices:
| Global |
Description |
Units |
Type |
X_<n> |
Distance from electrode |
cm |
Matrix |
T_<n> |
Distance from electrode |
\μsec |
Matrix |
S_<n> |
Distance from electrode |
\μsec |
Matrix |
The string "<n>" in the global variable name is set to 1 for the first
x(t) relation, 2 for the next etc.
You have to declare the Global variables before the loop if
- the instruction is placed in the body of a Do loop and
- these global variables are used in arithmetic, in a
condition of an If_line or a condition of an
If_block.
Declaring is not required if the variables are only used outside
the loop, in procedure Calls, in Say statements or for
substitution in normal input statements.
[This option is not on by default, but its setting is remembered
from one call to the next.]
Can be used to force a vertical scale in the x(t) relation plot,
e.g. when you wish to overlay several of them.
Go to the top level,
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to the topic index,
to the table of contents, or to the full text.
Formatted on 21/01/18 at 16:55.