[GRASS5] Re: more on color rules

[Michael Barton]

Helena,

What started this discussion was (1) a suggestion by me that there are 
probably quite a few nice color tables out there and wouldn't it be 
nice if there was a place on the GRASS site where people share them and 
(2) an observation that the color=rules option doesn't work in the 
autogenerated GUI for 5.7.

Since the subject's been raised however, it seems worthwhile to relook 
at how r.colors operates. As it stands now, colors=[options] only works 
for a limited set of predefined color tables, using other color tables 
can only be done via a command line redirection command (not available 
from the autogenerated GUI without scripting on top of the existing 
interface) and not through the colors=[options] format where it would 
seem to go, and interactive color table generation is accomplished 
through the color table loading argument--colors=rules--which doesn't 
work in the autogenerated GUI. The rast=[map] option is eminently 
sensible. However, the rest of it doesn't seem very consistent or 
'intuitive' (that is reasonably easy to figure out without looking it 
up all the time). Since GRASS is being redone at the 5/6 boundary, it 
wouldn't hurt to see if this important set of functions can be made 
more straightforward to use.

I realize that I'm one of those 'Mac people' who are constantly saying 
that we should be stressing our mousing fingers rather than trying to 
remember command-line syntax. But I must ashamedly admit that I 
sometimes prefer the command line. However, I really hate trying to 
remember and accurately type in a redirect the long and complex 
pathways where I might stash a color table I want to use ;-)

Saludos,
Michael

______________________________
Michael Barton, Professor & Curator
School of Human Origins, Cultures, & Societies
Arizona State University
Tempe, AZ  85287-2402
USA

voice: 480-965-6262; fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
On May 13, 2004, at 7:19 AM, Helena wrote:

> Michael,
>
> if I understand your suggestions correctly, there should already be 
> there
> (at least in the command line version)
>> Given this, it seems that there needs to be 2 options for reading in 
>> files: rules=[predefined rules, including the default GRASS set]
>
> that is already there, through option color=
> and you use either the predefined set of color tables or your own 
> rules,
> if you have the rules in a file you redirect that file to the command
> as explained by Glynn in his previous email
>
> and
>> map=[for reading rules from another map];
>
> that is there as an option rast=name
>
> and one flag for interactive
>> rule creation on the fly.
>
> that is there through option color=rules
>
> Helena
>
> The flag would override the options (more
>> convenient than having to make sure the options are blank in the 
>> GUI). I definitely like the idea of having the rules option somehow 
>> autogenerate a list in the GUI. For the CLI, the displayed options 
>> could be limited to the default GRASS set to keep it from getting too 
>> cluttered.
>> Michael Barton
>> ____________________
>> C. Michael Barton, Professor
>> School of Human Origins, Cultures, & Societies
>> PO Box 872402
>> Arizona State University
>> Tempe, AZ  85287-2402
>> USA
>> Phone: 480-965-6262
>> Fax: 480-965-7671
>> www: <www.public.asu.edu/~cmbarton>
>> On May 11, 2004, at 2:01 AM, grass5-request at grass.itc.it wrote:
>>>
>>>>>>> Also, it won't even get this far from the autogenerated GUI
>>>>>>> because it conflicts with the type=[option] argument. There
>>>>>>> needs to be a 'none' selection for the type option in the GUI
>>>>>>> header.
>>>>>>
>>>>>>
>>>>>> It needs to be a separate menu entry; exactly the same issue also
>>>>>> applies to the rast= option.
>>>>>
>>>>>
>>>>> What about a function which reports the names of the currently
>>>>> existing files in $GISBASE/etc/colors/ ? A function which
>>>>> returns the file names as comma separated list?
>>>>
>>>>
>>>> The problem here is that the list could grow rather quickly now that
>>>> it can be extended without having to write any code.
>>>
>>>
>>>
>>> I don't see this as a big problem if the default install is limited 
>>> to
>>> a dozen or so default color scales (we shouldn't be drowning the 
>>> users
>>> with many like options IMO).
>>>
>>> If someone wants to install 200 custom rules files, they get to deal
>>> with the consequences... same as if they installed 200 TT fonts on 
>>> their
>>> computer.
>>>
>>>
>>> Perhaps we should add a -l flag to list available rules? Then the
>>> default help page/parser stays clean.
>>>
>>>
>>> see 'g.mapsets -l'
>>>
>>>
>>> Hamish
>>>
>>>
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>
>