[GRASSLIST:4174] getting the categories from rast/vect files?

[Jeff D. Hamann]

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