[GRASSLIST:8020] Re: dead lines?

[M S]

being familar with other softwares, they have an "oops" command, that
allows you to backup once making an error.  they call it an audit
trail.  it would be so sweet if this was in grass.  it sounds like its
1/2 way there because the lines are deleted but not "gone".  having a
nice "step backwards" would be a massive help for large ditizing
projects.

great stuff! lovein GRASS more and more every day!

On 8/22/05, Radim Blazek <radim.blazek at gmail.com> wrote:
> On 8/22/05, M S <mseibel at gmail.com> wrote:
> > so is there a way to "restore/ressurect" those lines that are dead?
> > if they are deleted can you have the software restore them if u made a
> > mistake when deleting them?
> 
> In theory eyes but it is not implemented in GRASS.
> Also line type is lost because type is set to 0 for dead lines.
> If you change in read_nat.c rows
> 
>          if (itype == 0)   /* is it DEAD? */
>         continue;
> 
> to
> 
>          if (itype == 0)   /* is it DEAD? */
>              itype = GV_LINE;
> 
> it should change dead elements to lines.
> 
> In future it would be nice to reuse the space, there is already
> struct recycle *recycle; for list of deleted lines in vector header
> but it is not implemented.
> 
> Radim
> 
> 
> > thanks
> >
> > On 8/22/05, Radim Blazek <radim.blazek at gmail.com> wrote:
> > > On 8/18/05, M S <mseibel at gmail.com> wrote:
> > > > I read that v.clean "removes dead lines from your map.  Dead lines are
> > > > vectors that have been marked for deleted in v.digit."
> > > >
> > > > I'm confused about these dead lines.  In v.digit (using grass 6.0) i
> > > > delete lines and they go away, and then i get prompted to remove the
> > > > associated record from the database.
> > > >
> > > > Are these lines really deleted at this point?
> > > >
> > > > It sounds like they are not removed until v.clean is run.  if this is
> > > > the case, can these lines be restored PRIOR to running v.clean?
> > > >
> > > > Can someone rephrase  what v.clean does and what "dead lines" are?
> > > >
> > > > thanks!
> > >
> > >
> > > If you delete a line in v.digit, it is only marked in the file as 'dead' but
> > > it remains there and occupies space. If you run any module which
> > > realy reads and writes lines (not g.copy) it writes only lines which
> > > are 'alive'.
> > > Usually you don't need to think about dead lines.
> > >
> > > Radim
> > >
> >
>