[GRASS-user] min and max coord values

[temiz]

Glynn Clements wrote:
> temiz wrote:
>
>   
>>>> I want to get min and max coord values from  of catagorized raster
>>>> map.
>>>>
>>>> something like:  r.stats -agn hey6 > gives minx maxx miny maxy
>>>> is it possible  ?
>>>>     
>>>>         
>>> do you mean you want the coordinates of the bounding boxes surrounding
>>> each category?
>>>
>>> loop over each CAT (`r.describe`), create a MASK or new map based on
>>> that cat, then 'g.region -p zoom='.
>>>       
>> thank you and other friends
>>
>> I wrote a script to calculate the coordinates of  bounding box of each 
>> category using "g.region -p zoom="
>>
>> I am wondering if  "r.stats -agn"  is second alternative ?
>>
>> My raster map is something like some islands.
>> if I get coord value of each category , I can calculate most north- 
>> south and, most west- east, and then determine the coords of  minimum 
>> bounding  box?
>>     
>
> This is more efficient, particularly for many categories, but it
> requires a bit more work. The attached script takes the output from
> "r.stats -gn" and computes the bounding boxes for each category, e.g.:
>
> 	r.stats -gn fields | ./bbox.awk | sort -n
>
>   
> ------------------------------------------------------------------------
>
> #!/usr/bin/awk -f
> {
> 	if ($3 in n)
> 	{
> 		if (n[$3] < $2) n[$3] = $2
> 		if (s[$3] > $2) s[$3] = $2
> 		if (e[$3] < $1) e[$3] = $1
> 		if (w[$3] > $1) w[$3] = $1
> 	}
> 	else
> 	{
> 		n[$3] = s[$3] = $2
> 		e[$3] = w[$3] = $1
> 	}
> }
>
> END {
> 	for (i in e)
> 		print i,n[i],s[i],e[i],w[i]
> }
>   
Thank you again

I preferred r.stats, because its output more is manageable than 
g.region's in terms of querying.
The awk script solved the issue practically.
I was thinking to port the data to postgresql to find min, max coord 
values for each category.

By the way just an idea:

can  "g.region zoom=" work with respect to cat value of a map in grass's 
future releases ?

regards


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.