Specification of 2D electrodes.

The input data for a straight section (s) are:

(1) the coordinates r and z of the first end -that is, the perpendicular distance from the axis (or the distance x in planar symmetry) and the distance along the axis- for the first end,

(2) the coordinates r (or x) and z for the second end.

The input data for a circular arc section (cir) are:

(1) r (or x) and z for the first end,

(2) r and z for the second end,

(3) r and z for the centre of curvature.

A semicircle is NOT ALLOWED (because there are two possible choices of semicircle), but it can be entered as 2 quarter circles.

Other shapes can be generated by an external program. An example is given by program 11: which deals with the generation of the segments of a hyperbolic surface.

More importantly, users can use their own equations to produce a very wide range of shapes.

Other electrode information is explained elsewhere:

Voltages

Subdividing 2D electrodes

Stretching

The following comments are intended primarily for those users who are editing or constructing an 'input data file' without the use of the data-builder -that is, pre-processor:

But Manual editing is certainly not recommended -it is a relic from the time when the databuilder was not available All users are strongly encouraged to use the databuilder, which always gives the correct formats and which has many options for which the formats are not described or easily deduced.

If the first line of the input data starts with 't' (for 'touching the previous section') then it is assumed that the first end of the present section is the second end of the previous section, and so it does not have to be specified again. The centre of curvature does have to be specified again (for a circular arc).

But 't' does not have to be used when electrodes touch -instead simply specify the first end again.

In versions of the program before March 1998 the first line of the input data had to start with either 't' or 'n' (for 'not touching the previous section'), and could not be omitted. For compatibility with older data files a line starting with 'n' is still allowed, but is now ignored.

To disable the inscribing correction there should be an 'n' in the 15th space of the line that starts with 'c', and then the correction will be disabled for all the following electrodes.