[GRASSLIST:7912] Re: r.proj takes a very long time / does not complete

Morten Hulden morten at untamo.net
Mon Aug 15 17:14:55 EDT 2005


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
>>
>>
>>




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