[GRASSLIST:4187] Re: getting the categories from rast/vect files?

[Markus Neteler]

Jeff,

sorry for the delay - I have two deadlines these days and
will answer asap (I want to try below).

For the first question: Did you use SPEARFISH here?
I wonder about the "States Plane" (SPEARFISH is UTM).

If you use other data, is there a way to try those?

More soon,

 Markus

On Mon, Jul 29, 2002 at 10:34:09AM -0700, Jeff D. Hamann wrote:
> I've been importing a bunch of e00 files that contain many fields (I read in
> Neter and Mitasova, 2002 - a great book!) that grass5 only handles one
> attribute per feature (I hope I'm saying that correctly). My questions are
> these:
> 
> 0) When trying to perform the operatons in Section 9.4.2 of Neter and
> Mitasova (2002), I get a seemingly different result for my map as the final
> image is very peaked about zero and very long tails in both directions.
> 
> The original map contains the ranges...
> 
> | Type of Map: raster Number of Categories: 255 |
> | Data Type: CELL |
> | Rows: 2751 |
> | Columns: 3528 |
> | Total Cells: 9705528 |
> | Projection: State Plane (zone 0) |
> | N: 120498.70412715 S: 37936.60595648 Res: 30.01166782 |
> | E: 1367616.71679898 W: 1261735.55273279 Res: 30.01166782 |
> | Range of data: min = 0 max = 255 |
> 
> my cos_i map has a range of -0.282548 to 0.999974
> 
> | Type of Map: cell Number of Categories: 255 |
> | Data Type: FCELL |
> | Rows: 714 |
> | Columns: 912 |
> | Total Cells: 651168 |
> | Projection: State Plane (zone 0) |
> | N: 68357.7369186 S: 46937.21802326 Res: 30.00072674 |
> | E: 1291769.12014735 W: 1264406.2774157 Res: 30.00311703 |
> | Range of data: min = -0.282548 max = 0.999974 |
> | Data Source: |
> | Data Description: |
> | generated by r.mapcalc |
> | Comments: |
> | cos(90.0-60.183533)*cos(temp_slp)+sin(90.0-60.183533)*sin(temp_slp) |
> | *cos(172.455505-temp_asp_n) |
> 
> 
> and my final map (the spot.pcorr equivalent) has values that range from
> 
> | Type of Map: cell Number of Categories: 255 |
> | Data Type: FCELL |
> | Rows: 714 |
> | Columns: 912 |
> | Total Cells: 651168 |
> | Projection: State Plane (zone 0) |
> | N: 68357.7369186 S: 46937.21802326 Res: 30.00072674 |
> | E: 1291769.12014735 W: 1264406.2774157 Res: 30.00311703 |
> | Range of data: min = -44827896.000000 max = 5103264.000000 |
> | Data Source: |
> | Data Description: |
> | generated by r.mapcalc |
> | Comments: |
> | b10*(cos(90.0-60.183533)/temp_cos_i) |
> 
> How did the ranges get to be so large? I've got more diagnostics to perform,
> but where are the most common problems in this procedure for newbies?
> 
> 
> 1) I'd like to produce thematic maps from a vector file using a field that
> was imported from the e00 file. I having a little trouble trying to do that
> since I'm not sure what fields were imported.
> 
> 2) I'd *really* like to make use of the database features using ODBC since I
> use MySQL and MS Access for my work and need to be able to export dbf files,
> etc for other. Is there a tutorial for setting up ODBC under cygwin? I've
> tried doing the spearfish example using postgresql and I wasn't successful.
> 
> 3) I need to perform something like a "FREQUENCY" function in arc/info to
> obtain the number of pixels in a polygon. I can convert the polygons into
> rasters, but then what?
> 
> I know I've asked lots of newbie questions here and you've been very
> helpfull.
> 
> Thanks,
> Jeff.
> 
> Jeff D. Hamann
> Hamann, Donald & Associates, Inc.
> PO Box 1421
> Corvallis, Oregon USA 97339-1421
> Bus. 541-753-7333
> Cell. 541-740-5988
> jeff_hamann at hamanndonald.com
> www.hamanndonald.com

-- 
Markus Neteler

ITC-irst, Istituto per la Ricerca Scientifica e Tecnologica
     Project on Predictive Models for the Environment    
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