Re: true landscape orientation

From: Fred Clare <fredclare_at_nyahnyahspammersnyahnyah>
Date: Sun, 11 Jan 2009 16:02:13 -0700


Thanks for your input. In looking at my Postscript Reference
Manual your observation about inserting a Postscript comment:

%%Orientation: Landscape

in the initial comments section of a Postscript file should
indeed afford interpreters the ability to position the plots
as you desire. However, neither of the Postscript viewers I am using
on my Mac ("gs" and "preview") seems to respond to having this comment
in a file. Let me know what you get with the trivial Postscript
file attached. Given your experience with GV it would appear
that Postscript interpreters are not rock solid in their honoring
the orientation comment. :-) How would you expect a Postscript
printer to react to the landscape orientation comment?

I could easily insert an orientation comment in the lower level
Postscript driver when a Postscript landscape workstation
is opened. I think things get a little tricky when considering
Postscript created from NCL. For example, when the gsnMaximize
resource is set to True, then the resource gsnPaperOrientation can
be applied on a frame-by-frame basis. To have orientation
comments in the output Postscript properly reflect this whould
require inserting %%PageOrientation comments at the Postscript
page level. Effecting this at the NCL level would require
implementing a function call for the Postscript driver to
respond to, and NCL would have to make that call where appropriate.
Assuming that we can settle for a global orientation comment,
there are still considerations for NCL. Since the resource
gsnMaximize can be set on a frame-by-frame basis, and that
may or may not result in an individual frame being produced
in either landscape or portrait mode, we are back in the same
situation as with the above considerations for gsnPaperOrientation.

I see nothing in my PDF Reference Manual the would be the
equivalent to the Postscript orientation comment. But my
manual is eight years old, so maybe there has been an addition.

Before proceding, I will wait for Mary to weigh in, since
she knows the details of how NCL interfaces with the the lower
level codes in this area.


Fred Clare

On Jan 9, 2009, at 6:32 PM, Rob Nicholas wrote:

> Adding "%%Orientation: Landscape" to the header of the PostScript file
> seems to get you part way there -- GV displays the page in landscape
> mode but upside down.
> On Fri, Jan 9, 2009 at 12:14 PM, Fred Clare <> wrote:
>> On Jan 9, 2009, at 12:36 PM, Rob Nicholas wrote:
>>> Mary,
>>> On Fri, Jan 9, 2009 at 8:18 AM, Mary Haley <> wrote:
>>>> Maybe there's a flag that one can put in a PS/PDF file that tells
>>>> other PS/PDF viewing applications that the image has been
>>>> rotated, and
>>>> hence it should automatically show it in landscape mode. I'll
>>>> ask our
>>>> PS/PDF expert about this.
>>> I'm almost certain this is true -- most other applications I've used
>>> that produce PostScript output seem to get this right. Unless it's
>>> PDF
>>> (rather than PostScript) I'm thinking of (although the problem
>>> exists
>>> with NCL's PDF output, too).
>> I know of no Postscript or PDF operator that would specifically
>> indicate to a viewing application to view the image as being rotated.
>> Each language has a rotate operator, but that simply rotates the
>> image within the context of the internal coordinate systems.
>> Perhaps you could supply us with an example file that seems to
>> have this property and I could look in there to see what is being
>> used.
>> Fred Clare
>>> On Fri, Jan 9, 2009 at 8:18 AM, Mary Haley <> wrote:
>>>> For now, can you use the "Rotate" button on your viewer to rotate
>>>> the image as desired?
>>> Sure, though it gets to be a bit of a chore when you're producing 20
>>> or 50 plots at a time. Let me know if you unearth a solution.
>>> Thanks,
>>> Rob
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Received on Sun Jan 11 2009 - 16:02:13 MST

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