Jane Yang <jane.juen.y...@gmail.com> writes: > Hi all, > > Happy Monday! Hoping the collective genius of this listserv can help me. I > have vector contours data (source: > http://192.156.137.110/gis/search.asp?id=318) that I would like to convert > to a surface raster. Two questions: > > 1. What are peoples' opinions about the use of spgrass6's r.surf.contour > functionality vs raster's rasterize function? My basic understanding is > that GRASS has a more robust algorithm for interpolation, but please do > correct me if I'm mistaken. > > 2. I have been pursuing the r.surf.contour option because initial trials > with rasterize hasn't converted the majority of the data in the vector > contour file. However, when I try to load the vector file into a temporary > GRASS environment, I hit the following error in red, that results in no > data being transferred over to the raster. > > initGRASS("/Applications/GRASS-6.4.app/Contents/MacOS", home=tempdir(), > override = T) > system("g.region -d") > execGRASS("v.in.ogr", dsn = "path/to/file, > layer = "kenya_rainfall_distribution", output = "rf_raw2", > snap = 1e-14) > Warning message: > In execGRASS("v.in.ogr", dsn = paste(dd, "rainfall", "ilri", sep = "/"), : > The command: > v.in.ogr dsn=/VOLUMES/AUSTEN/OAF/KE-exp-extras/data/rainfall/ilri > layer=kenya_rainfall_distribution output=rf_raw2 snap=1e-14 > produced at least one warning during execution:
> ERROR 4: .shx file is unreadable, or corrupt.
The question is: is your .shx file readable or is it corrupt?
If I understand correctly, this file contains a spatial index, so I
think you can rename it and try again?
The rest should be follow-up errors.
Hope this helps,
Rainer
> ERROR 4: Failed to open file
> /VOLUMES/AUSTEN/OAF/KE-exp-extras/data/rainfall/ilri/._kenya_rainfall_distribution.shp.
> It may be corrupt or read-only file accessed in update mode.
>
> execGRASS("v.to.rast", input = "rf_raw2", output = "rf_rast", column =
> "COLOR",
> labelcolumn = "TYPE")
> rf.raster <- execGRASS("r.surf.contour", input = "rf_rast",
> output = "rfraster")
>
> rf.raster
> [1] 0
> attr(,"resOut")
> character(0)
> attr(,"resErr")
> [1] " 0%\b\b\b\b\b 100%\b\b\b\b\b"
>
>
> However, I have no problem plotting the map in base plot. Any suggestions
> on how to work around this would be much appreciated.
>
> Thank you,
> Jane
>
> [[alternative HTML version deleted]]
--
Rainer M. Krug
email: Rainer<at>krugs<dot>de
PGP: 0x0F52F982
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