The size of the ellipses depends upon the parameter ERSCALE which should be set before
the data are read in so that the
WORLD application can calculate the viewing area properly.
This allows the ellipse size to be varied so that it can be drawn for different confidence
If the value is not specified on the command line, the current value is used. The current value is initially set to FALSE.
WORLD DATA(which automatically sets the graph limits) is to work properly, the global parameter PONGO_ERSCALE should have been set by
READF. However, if this facility is not required, it is perfectly acceptable to set ERSCALE when invoking ELLIPSES.
[The value of the global parameter PONGO_ERSCALE is used. If PONGO_ERSCALE is not defined, the default value 1.0 is used.]