### New

Any segment opened with gr_segm must now be closed with the following new entry point after all the data it contains has been sent to the metacode:

- gr_segm_close(error)

The following conditions applies:

- at close time (gr_segm_close), a segment is implicitely drawn by GTV,
- attempting to send segment data to the metacode while there is no segment currently opened is an error,
- attempting to open (gr_segm) a new segment while the previous one is not closed (gr_segm_close) is an error,
- attempting to close (gr_segm_close) twice a segment is an error.

Given the first point above, the necessity for an Append mode for gtview is severely reduced. Basically, what you will probably have to do is to replace all the statements gtview('Append') by gr_segm_close(error). The only purpose to call gtview('Append') is now when you are filling a unique segment, and want the user to see in real-time this segment being filled (e.g. a curve showing the convergence of a computation, or an interactive drawing with the cursor, ...).

Instead of calling gr_exec('CLEAR SEGMENT FOO'), programmers can invoke the public subroutine gt_clear_segment(name,present,error) where name is the segment(s) name to be destroyed (e.g. if name is FOO it will destroy all the segments named FOO:*), present is a logical indicating if an error should be raised if no segment with such a name is found, and error is an inout logical error flag (i.e. it keeps its entering value if no error occurs).