[GRASSLIST:7950] Re: r.proj takes a very long time / does not complete

[Jason Horn]

Ian, Morten,

Thanks so much for pointing out the problem.  I have seceded in  
projecting the raster layer, with the help of the v.in.region box  
trick.  I have set the resolution to an approximation of what I think  
is right.  However, how can I really match the resolution in the new  
state plane location to the resolution from the old lat-lon location?

- Jason


On Aug 15, 2005, at 5:25 PM, Ian MacMillan wrote:

> A simple way to do this is to make a vector box of your region in  
> the first location using v.in.region.  Go to your new location,  
> v.proj that vector in, and set your region to the new vector.  Then  
> use r.proj on the raster you want to project.  You will still have  
> to set the resolution on your own though.  Hope this makes sense.
>
> -Ian
>
> On Aug 15, 2005, at 2:14 PM, Morten Hulden wrote:
>
>
>>
>>
>> No wonder it takes forever. Your output location has 527482690275  
>> cells (847325 x 622527) to project.
>>
>> You should adjust the boundaries or resolution of your NAD83  
>> location to something more reasonable. Before running r.proj try  
>> to set a resolution value that roughly matches the resolution of  
>> your input map (g.region res= ), e.g. something like 1000 m.
>>
>> Don't know about boundaries for your location (TX unknown area to  
>> me) but you may want to check those as well. No need to cover more  
>> than what is necessary.
>>
>> rgds
>> Morten
>>
>>
>> Jason Horn wrote:
>>
>>> Morten,
>>> Thanks for looking at this for me.  Below are the files you asked  
>>> for.
>>> PROJ_INFO for the source lat-lon location:
>>> name: Latitude-Longitude
>>> datum: wgs84
>>> towgs84: 0.000,0.000,0.000
>>> proj: ll
>>> ellps: wgs84
>>> cellhd file for  KEWX20040710_025420:
>>> proj:       3
>>> zone:       0
>>> north:      34:00:17.832478N
>>> south:      25:11:59.799175N
>>> east:       92:43:25.599215W
>>> west:       103:19:56.000785W
>>> cols:       1000
>>> rows:       830
>>> e-w resol:  0:00:38.190402
>>> n-s resol:  0:00:38.190402
>>> format:     -1
>>> compressed: 1
>>> PROJ_INFO file for the destination NAD83 location:
>>> name: Lambert Conformal Conic
>>> datum: nad83
>>> towgs84: 0.000,0.000,0.000
>>> proj: lcc
>>> ellps: grs80
>>> a: 6378137.0000000000
>>> es: 0.0066943800
>>> f: 298.2572221010
>>> lat_0: 31.1666670000
>>> lat_1: 27.4166670000
>>> lat_2: 34.9166670000
>>> lon_0: -100.0000000000
>>> x_0: 1000000.0000000000
>>> y_0: 1000000.0000000000
>>> WIND file for the destination NAD83 location:
>>> proj:       99
>>> zone:       0
>>> north:      1196061
>>> south:      573534
>>> east:       1563147
>>> west:       715822
>>> cols:       847325
>>> rows:       622527
>>> e-w resol:  1
>>> n-s resol:  1
>>> top:        1
>>> bottom:     0
>>> cols3:      847325
>>> rows3:      622527
>>> depths:     1
>>> e-w resol3: 1
>>> n-s resol3: 1
>>> t-b resol:  1
>>> Thanks again!
>>> - Jason
>>> On Aug 13, 2005, at 12:14 PM, Morten Hulden wrote:
>>>
>>>> Jason Horn wrote:
>>>>
>>>>
>>>>> I have a long-standing problem with r.proj.  I have never been   
>>>>> able to complete a successful re-projection of a raster file.   
>>>>> For  example, I am trying to pull in a raster file from a  
>>>>> location that  is lat-lon, WGS84 into a location that is state- 
>>>>> plane meters,  NAD83.  The raster grid is relatively small,  
>>>>> 1000 cols by 830  rows.  I start r.proj like this:
>>>>> r.proj input=KEWX20040710_025420 location=TX_ll_WGS84   
>>>>> mapset=PERMANENT output=proj1 method=nearest Although my CPU  
>>>>> stays  pegged at close to 100% usage, the progress bar never  
>>>>> moves  forward and nothing happens, even if I leave it for many  
>>>>> hours.   Can anyone tell me what's going on here?
>>>>>
>>>>>
>>>>
>>>> In order to help you I would like to see:
>>>>
>>>> 1) The PROJ_INFO file for your latlon location
>>>> 2) The cellhd file of the KEWX20040710_025420 map in the latlon   
>>>> location
>>>> 3) The PROJ_INFO file for your NAD83 location
>>>> 4) The WIND file for your NAD83 location
>>>>
>>>>
>>>>
>>>>
>>
>>
>
>
>