[GRASSLIST:3606] v.surf.idw

[Sabine Grabner]

hello,  
 
i try to interpolate my meteorological data with the following vector data: 
 
 
rsdb=> select * from temp20000130180000; 
    x    |    y    |  z   | parameter | data | refper |        name          
---------+---------+------+-----------+------+--------+--------------------- 
 10.7814 | 46.7581 | 2070 |         4 |   -7 |      0 | Kurzras 
 11.1667 | 46.6734 |  392 |         4 |   34 |      0 | Meran 
    10.5 |    46.9 | 1360 |         4 |   25 |      0 | Nauders 
  11.023 | 46.8672 | 1938 |         4 |   -2 |      0 | Obergurgl 
  10.875 | 46.9242 | 2850 |         4 |  -44 |      0 | Pitztaler Gletscher 
 10.8794 | 46.9269 | 2850 |         4 |  -46 |      0 | Pitztaler Gletscher 
  10.913 | 46.8594 | 1906 |         4 |   -1 |      0 | Vent 
(7 rows) 
 
rsdb=> \d temp20000130180000 
       Table "public.temp20000130180000" 
  Column   |         Type          | Modifiers  
-----------+-----------------------+----------- 
 x         | double precision      |  
 y         | double precision      |  
 z         | integer               |  
 parameter | integer               |  
 data      | double precision      |  
 refper    | integer               |  
 name      | character varying(20) |  
 
rsdb=>  
 
first question: 
=============== 
 
can anyone tell me how to set a mask as mentioned in the v.surf.idw as the 
command r.mask is neither documented nor does it work on my grass57 
 
second question: 
================ 
 
interpolationg with r.surf.idw all cells does have the same value !?  
i played around with the attribute field, to catch the required collumn 
'data'. it seems that i got it as every cell has '-2' which matches only to 
this collumn. 
by the way, i casted my int data to float as v.surf.idw matches field='which 
decimal attribute'. is this redundant? 
 
GRASS 5.7.-cvs:~/diss/grassdata > v.surf.idw in=temp20000130180000 
out=temp20000130180000 field=4 
v.surf.idw: 
WARNING: Vector used instead of sites. 
Reading sites map (temp20000130180000) ...         6 sites loaded 
Interpolating raster map <temp20000130180000> ... 2800 rows ... done  
GRASS 5.7.-cvs:~/diss/grassdata > d.rast temp20000130180000 
 100% 
GRASS 5.7.-cvs:~/diss/grassdata > d.what.rast 
 
Buttons 
 Left:  what's here 
 Right: quit 
 
196272.91666667(E) 5215609.58333333(N) 
temp20000130180000 in sabine57, quant   (-2) 
temp20000130180000 in sabine57, actual  (-2.000000) 
 
169731.25(E) 5184692.91666667(N) 
temp20000130180000 in sabine57, quant   (-2) 
temp20000130180000 in sabine57, actual  (-2.000000) 
GRASS 5.7.-cvs:~/diss/grassdata >  
 
 
any advice welcome! thanks a lot.  
 
yours, sabine