[GRASSLIST:2785] Re: mailing list for beginners

GRASS GRASS user
1

well, i think that today there's no distinction between " grass user" and "grass specialist"
but if we have a growing open gis/software community then this distinction wil appear ..if not, grass will remain a software used by a little highly specialized elite of researchers...
so, i think that what we are discussing here is very natural in this context of increasing use of open gis...

From: Paul Kelly <paul-grass@stjohnspoint.co.uk>
To: samuel cavalcante <grassmanbr@hotmail.com>
CC: grasslist@baylor.edu
Subject: Re: [GRASSLIST:2779] mailing list for beginners
Date: Sat, 28 Feb 2004 14:42:57 +0000

samuel cavalcante wrote:
>
[...]
> why not create a beginners mailing list?
> i am expending some weeks trying to run nviz but i always fail...(so, maybe
> it must be writen a "grass for dummies" for people like me...)...the error
> mesages are driving me insane (laughs)...

Difficulties in running NVIZ are not a simple beginner's problem. It is
probably not your fault and likely some complex bug. There is often not
a simple answer and there is a good chance that the only way you will
get NVIZ running well on your system is to become an expert programmer
and debug it yourself!

_________________________________________________________________
MSN Hotmail, o maior webmail do Brasil. http://www.hotmail.com

2

I would not worry about a beginners list just yet. I have found everyone on this list to be very helpful, and tolerant of novice questions. If at sometime in the future the volume of traffic on this list became too large, then your suggestion would be logical. But in the mean time, do not hesitate to post beginner questions. Maybe some of us "intermediate" users will be able to answer your questions, and in so doing, contribute something back to the GRASS community and show our appreciation for the help we have received in the past from the "expert" members of the list.

Rich

samuel cavalcante wrote:

well, i think that today there's no distinction between " grass user" and "grass specialist"
but if we have a growing open gis/software community then this distinction wil appear ..if not, grass will remain a software used by a little highly specialized elite of researchers...
so, i think that what we are discussing here is very natural in this context of increasing use of open gis...

From: Paul Kelly <paul-grass@stjohnspoint.co.uk>
To: samuel cavalcante <grassmanbr@hotmail.com>
CC: grasslist@baylor.edu
Subject: Re: [GRASSLIST:2779] mailing list for beginners
Date: Sat, 28 Feb 2004 14:42:57 +0000

samuel cavalcante wrote:
>
[...]
> why not create a beginners mailing list?
> i am expending some weeks trying to run nviz but i always fail...(so, maybe
> it must be writen a "grass for dummies" for people like me...)...the error
> mesages are driving me insane (laughs)...

Difficulties in running NVIZ are not a simple beginner's problem. It is
probably not your fault and likely some complex bug. There is often not
a simple answer and there is a good chance that the only way you will
get NVIZ running well on your system is to become an expert programmer
and debug it yourself!

_________________________________________________________________
MSN Hotmail, o maior webmail do Brasil. http://www.hotmail.com

--
Richard Greenwood
www.greenwoodmap.com

3

On Sun, 29 Feb 2004, Richard Greenwood wrote:

I would not worry about a beginners list just yet. I have found everyone
on this list to be very helpful, and tolerant of novice questions. If at
sometime in the future the volume of traffic on this list became too
large, then your suggestion would be logical. But in the mean time, do
not hesitate to post beginner questions. Maybe some of us "intermediate"
users will be able to answer your questions, and in so doing, contribute
something back to the GRASS community and show our appreciation for the
help we have received in the past from the "expert" members of the list.

That sounds like what I was trying to say but expressed much more clearly :slight_smile:
Really I was just saying that questions about NVIZ not working are not
usually 'beginner's questions' and there is no need for a separate list
for them.

4

On Mar 1, 2004, at 4:24 AM, Paul Kelly wrote:

On Sun, 29 Feb 2004, Richard Greenwood wrote:

I would not worry about a beginners list just yet. I have found everyone
on this list to be very helpful, and tolerant of novice questions. If at
sometime in the future the volume of traffic on this list became too
large, then your suggestion would be logical. But in the mean time, do
not hesitate to post beginner questions. Maybe some of us "intermediate"
users will be able to answer your questions, and in so doing, contribute
something back to the GRASS community and show our appreciation for the
help we have received in the past from the "expert" members of the list.

That sounds like what I was trying to say but expressed much more clearly :slight_smile:
Really I was just saying that questions about NVIZ not working are not
usually 'beginner's questions' and there is no need for a separate list
for them.

Well, as a beginner myself, I can say that questions about NVIZ may truly be beginners' questions. Being principally a Mac user, I'm not fluent with compilation of source code, so I obtained a binary installation of GRASS 5.0.3 from OpenOSX. Once I downloaded the Spearfish data set to run the tutorials, NVIZ is one of the first things I tried after d.rast and d.vec. Worked great. Didn't have much of a clue about what I was doing, but the pictures were pretty awesome.

I'm working my way through the book, "Open Source GIS: A GRASS GIS approach," and working some of the tutorials to find out how to use this program. Lurking on this list has provided some insight into GRASS's capabilities and shortcomingsg, and makes decyphering unix's innards worthwhile.

5

James Plante wrote:

> Really I was just saying that questions about NVIZ not working are not
> usually 'beginner's questions' and there is no need for a separate list
> for them.

Well, as a beginner myself, I can say that questions about NVIZ may
truly be beginners' questions. Being principally a Mac user, I'm not
fluent with compilation of source code, so I obtained a binary
installation of GRASS 5.0.3 from OpenOSX.

Yeah, but unfortunately there's a big difference between compiling
source code and compiling the NVIZ source code. The latter regularly
causes problems for people who otherwise have no problems compiling
source code.

Part of the problem is that NVIZ creates an additional Tk widget class
(Togl, the OpenGL canvas widget), which relies upon Tk internals. To
do this, it requires header files which aren't normally shipped with
binary Tk packages, so we have to include local copies of those
headers (and if the system's Tk library was built with modified
headers, we lose). It also involves using aspects of Tk which aren't
particularly well documented (and, I suspect, which may have changed
significantly between 8.3 and 8.4).

Another part of the problem is that OpenGL may use both the pthread
and C++ libraries, while Tk may use the pthread library. Both of those
libraries may have certain "quirks" that don't occur with other
libraries.

Unfortunately, there's also a difference between compiling source code
on MacOSX and compiling it on "normal" Unices. MacOSX is similar
enough that Unix code can be made to compile and run on it, but
different enough to cause problems. Here, the main issues are:

1. The OSX linker is significantly different from that on other
Unices, e.g. GNU ld.

2. OSX has "native" versions of both OpenGL and Tcl/Tk, in addition to
the traditional Unix/X11 versions. The native versions won't work with
Unix code (e.g. NVIZ), so if they end up getting used, the program
won't work. Unfortunately, getting "configure" to detect the presence
or absence of a header file or library is a lot easier than getting it
to determine whether the file which it detected is actually suitable
for the intended purpose.

--
Glynn Clements <glynn.clements@virgin.net>

6

On Mar 1, 2004, at 11:50 AM, Glynn Clements wrote:

James Plante wrote:

Really I was just saying that questions about NVIZ not working are not
usually 'beginner's questions' and there is no need for a separate list
for them.

Well, as a beginner myself, I can say that questions about NVIZ may
truly be beginners' questions. Being principally a Mac user, I'm not
fluent with compilation of source code, so I obtained a binary
installation of GRASS 5.0.3 from OpenOSX.

Yeah, but unfortunately there's a big difference between compiling
source code and compiling the NVIZ source code. The latter regularly
causes problems for people who otherwise have no problems compiling
source code.

</lurk>

Excuse me for jumping into this conversation. As an unix and Grass newbie (Mac, print background), I find this list an invaluable tool for getting up to speed. I only discovered Grass in mid-January and not having a lot of spare time, I couldn't, for the life of me, get Grass to compile. Blame it on the lack of experience. Then I noticed Lorenzo's binaries were available. Within a day, I had the program running. Thanks Lorenzo. Not being a professional, I still have a steep learning curve ahead.

Now for the reason that I jumped into the conversation. Since I have Grass 5.3 running on my main partition, I would like to offer the services of my second partition to Lorenzo and the developer team as a test bed for OS X distributions. I just use it for testing Apple's OS patches before I apply them to my working partition. Perhaps, I could document all the steps and put them on the wiki page for my fellow OS Xers as a guide. Other thoughts?

Thanks for your time.

Jeff Stubbs

<lurk>

----------
"Notice this rent in my garment; I am at a loss to explain its presence!
  I am even more puzzled by the existence of the universe."
            -- Jack Vance