Issue with hggroup and zlim

[John W. Eaton]

On 28-Aug-2008, David Bateman wrote:

| I'm trying to implement line series objects, and with the current hg 
| repository I see that
| 
| z = [0:0.05:5]; h =  plot3 (z, exp(2i*pi*z));
| 
| works fine, but
| 
| z = [0:0.05:5]; hold on; hg = hggroup(); h =  plot3 (z, 
| exp(2i*pi*z),'parent',hg);
| 
| 
| doesn't. Note that the "hold on" is need to avoid the hggroup being 
| cleared. The result is that the zlim is [-0.6,0.6] when it should be 
| [-1,1]. I took a quick look at graphics.cc and I can't see the reason 
| for this issue. Perhaps Michael or Shai can. For now I'm just going to 
| ignore it and go on with the line, etc series implementation.


I'm seeing this odd behavior after starting a fresh Octave session:

  octave:1> z = [0:0.05:5]; hold on; hg = hggroup();
  octave:2> get (hg)
  ans =
  {
    beingdeleted = off
    busyaction = queue
    buttondownfcn = [](0x0)
    children = [](0x0)
    clipping = on
    createfcn = [](0x0)
    deletefcn = [](0x0)
    handlevisibility = on
    hittest = on
    interruptible = on
    parent = -1.2009
    selected = off
    selectionhighlight = on
    tag = 
    type = hggroup
    userdata = [](0x0)
    visible = on
    __modified__ = on
    uicontextmenu = [](0x0)
  }

  octave:3> h =  plot3 (z, exp(2i*pi*z),'parent',hg);
  error: __go_line__: invalid parent
  error: called from:
  error:   /home/jwe/src/octave/scripts/plot/__line__.m at line 67, column 5
  error:   /home/jwe/src/octave/scripts/plot/line.m at line 41, column 5
  error:   /home/jwe/src/octave/scripts/plot/plot3.m at line 295, column 16
  octave:3> get (hg)
  ans =
  {
    beingdeleted = off
    busyaction = queue
    buttondownfcn = [](0x0)
    children = [](0x0)
    clipping = on
    createfcn = [](0x0)
    deletefcn = [](0x0)
    handlevisibility = on
    hittest = on
    interruptible = on
    parent = -1.2009
    selected = off
    selectionhighlight = on
    tag = 
    type = text
    userdata = [](0x0)
    visible = on
    __modified__ = on
    uicontextmenu = [](0x0)
    string = 
    units = data
    position =

       0   0   0

    rotation = 0
    horizontalalignment = left
    color =

       0   0   0

    fontname = Helvetica
    fontsize =  10
    fontangle = normal
    fontweight = normal
    interpreter = tex
    backgroundcolor = none
    displayname = 
    edgecolor = none
    erasemode = normal
    editing = off
    fontunits = points
    linestyle = -
    linewidth =  0.50000
    margin =  1
    verticalalignment = middle
  }


I don't understand how HG has magically been converted from an hggroup
object to a text object.

jwe