Programs for generating segments for a rectangular slot in a spherical cap, first method.

Please also see the powerful option for users to use their own equations to define electrode shapes.


The program itself and the compiled version are included in the CPO package: they have the names prog24.f90 and prog24.exe respectively. To run the program simply type 'prog24' as a command line.


Before doing that, set up the data file that is read by prog24. This data file must be called 'tempin.dat'. A read-only version of it is saved as 'prog24.dat', which contains (for xmpl3d24):


2. ! =radius of sphere

0.5 ! =z of centre of bounding circle

1.5 0.5 ! =x,y of a corner of the rectangular hole

400 ! =approximate total number of subdivisions

1 ! =voltage number

y ! the x=0 plane is a symmetry plane in the main CPO3D program (y/n)

y ! the y=0 plane is a symmetry plane in the main CPO3D program (y/n)

y ! ignore thin crescent at thin end of rectangle (y/n)


It is assumed here that:

(1) the centre of the sphere is at the origin,

(2) the centre of the rectangular hole is on the z axis.

In general these assuptions are not correct and so the resulting object will have to be shifted and/or rotated, as explained below.


After setting up tempin.dat and running prog24, a set of electrode data can be found in 'tempout.dat'.

These data should be copied and then pasted into a primary data file for CPO3D.


The 'transform' option should then be used to shift and/or rotate the object.

Finally the data for the object can be copied and pasted into the primary data file that deals with the complete system.


The data file shap3d24.dat was created in this way.


(When the final object is viewed in CPO3D some thin gaps might be seen between the inner edge of the main part of the sphere and the outer triangles that fill the parts that border the rectangular hole. These gaps exist because the points that define the inner edge do not coincide with the points that define the corners of the outer triangles. But both sets of points lie on the same circle. The gaps are therefore unimportant.)