[GRASSLIST:9065] Re: GRASS 6 in a nutshell tutorial

[Luigi Ponti]

Thanks Amish,

looking at v.info and r.info, it seems the two maps have the same 
projection (see below). However, when looking at the output "d.where -w" 
for a sample map point (the San Francisco Bay), the longitude is very 
different in the two maps:

                                                   WGS84 Co-ordinates
             EAST:             NORTH:               LON:
           
   -191114.6346037    -24240.66895625  143:03:58.588289W   29:24:27.1
(San Francisco Bay on the California State vector layer - WRONG)

  1839139.30311877    663981.00484798  122:19:50.783112W   37:57:48.1
(San Francisco Bay on the Elevation Model raster layer - CORRECT)

Do you think this could be due to an error in the import process or 
should I just look for another vector map?

Thanks again,

Luigi



v.info map=state layer=1
 +----------------------------------------------------------------------------+
 | Layer:    state                          
Organization:                     |
 | Mapset:   luigi                          Source 
Date:                      |
 | Location: Cal_nad83-zone3                Name of 
creator:                  |
 | Database: 
/home/andy                                                       |
 | 
Title:                                                                     |
 | Map Scale:  
1:1                                                            |
 | Map format: 
native                                                         |
 |----------------------------------------------------------------------------|
 |   Type of Map:  Vector (level: 
2)                                          |
 |                                                                            
|
 |   Number of points:       0               Number of areas:      
51         |
 |   Number of lines:        0               Number of islands:    
48         |
 |   Number of boundaries:   59              Number of faces:      
0          |
 |   Number of centroids:    51              Number of kernels:    
0          |
 |                                                                            
|
 |   Map is 3D:              
0                                                |
 |   Number of dblinks:      
1                                                |
 |                                                                            
|
 |   Projection: Lambert Conformal Conic (zone 
0)                             |
 |            N: 922206.900    S: 
-701781.905                                 |
 |            E: 1043412.917     W: 
-374425.808                               |
 |            B: 0.000         T: 
0.000                                       |
 |                                                                            
|
 |   Digitize threshold: 
0.00000                                              |
 |   
Comments:                                                                |
 |                                                                            
|
 +----------------------------------------------------------------------------+


r.info map=e10g at PERMANENT
 +----------------------------------------------------------------------------+
 | Layer:    e10g                           Date: Tue Nov  8 17:25:24 
2005    |
 | Mapset:   PERMANENT                      Login of Creator: 
andy            |
 | Location: 
Cal_nad83-zone3                                                  |
 | DataBase: 
/home/andy                                                       |
 | Title:     ( e10g 
)                                                        |
 |----------------------------------------------------------------------------|
 |                                                                            
|
 |   Type of Map:  raster              Number of Categories: 
5443             |
 |   Data Type:    
CELL                                                       |
 |   Rows:         
7192                                                       |
 |   Columns:      
11628                                                      |
 |   Total Cells:  
83628576                                                   |
 |        Projection: Lambert Conformal Conic (zone 
0)                        |
 |            N:    3353466    S:   -3838238   Res: 
999.95884316              |
 |            E:    6073284    W:   -5555183   Res: 
1000.04016168             |
 |   Range of data:    min =  -84 max = 
5443                                  |
 |                                                                            
|
 |   Data 
Source:                                                             |
 |                                                                            
|
 |                                                                            
|
 |                                                                            
|
 |   Data 
Description:                                                        |
 |    generated by 
r.proj                                                     |
 |                                                                            
|
 |                                                                            
|
 +----------------------------------------------------------------------------+

Hamish wrote:

>>I have imported both the vector and the raster with minimum trouble, 
>>since the first has a .prj file which GRASS recognized, and the second
>>
>>had a detailed import tutorial in the cygwin-GRASS install page. 
>>However, despite the fact the the two layers supposedly have the same 
>>NAD83 projection info (I did not enter anything manually), when I try
>>to  display them together on a GRASS monitor, the state layout is in
>>the  middle of the ocean compared to the elevation raster.
>>
>>Is there a way to overlap the two layers or to chek for a coordinate
>>error?
>>
>
>
>r.info and v.info will give you the map extents, you should then be able
>to figure out which is correct.
>
>Also try "d.where -w" to give you a lat/lon value for different parts of 
>your map which you can compare to the map on the wall.
>
>
>Hamish
>
>
>