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bio website staff.acecrc.org.au/~mdsumner
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visits member for 3 years, 8 months
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R, Manifold, GDAL, also interested in Python, topojson/D3 and NetCDF/HDF


Oct
31
comment Arctic EPSG:4326 map projection?
What is the ice data? Many products are delivered in a native polar stereographic projection (there's practically a standard for NSIDC/SSMI/AMSR-E, which is a rare happy bonus) that would be a better choice if that works for you. They tend not to be delivered with metadata included, but it's easy to find/apply. Are you just wanting to view the data or ultimately serve it up somehow? QGIS and R are good alternatives, but gdal ties it all together as usual.
Oct
24
comment How to create random point in according polygon for each dataset entry in a list (with R)
Right, I missed that part. You need to replace wrld_simpl[i, ] with wrld_simpl[s[i,"poly-id", ] or similar. Reproducible examples help, I'll try to make one for you if I get around to it.
Oct
23
comment Is there a software package that allows users to create map tiles?
gdal.org/gdal_retile.html
Oct
15
comment What is the best plain text format for georeferenced raster data?
"Best" here is kind of funny, it's not a good way to do it at all. xyz is inefficient and has no metadata, ESRI Ascii is more efficient and many software apps actually know it's a grid and how to use it, but still it has no projection metadata or extra efficiency. Use something good like GeoTIFF.
Oct
14
answered How to create random point in according polygon for each dataset entry in a list (with R)
Oct
3
answered How to convert 'RasterBrick' object to 'im' object in R?
Oct
3
comment How to convert 'RasterBrick' object to 'im' object in R?
Ah, my typo - sorry.
Oct
3
comment How to convert 'RasterBrick' object to 'im' object in R?
What is "geostatp"? I started on an answer but baulked at assuming I could find that on CRAN. Perhaps it's local? The behaviour you seek would be provided by spatstat and maptools in my imagination but perhaps not yet?
Oct
3
comment How to convert 'RasterBrick' object to 'im' object in R?
some_file is your problem, you can see it and we cannot
Sep
26
comment How can I fix a geoTiff with an incorrect CRS?
You'll need to check with the provider/creator, it's their fault. No one can guess though you can get away with that as a last resort.
Sep
25
comment How can I fix a geoTiff with an incorrect CRS?
gdalwarp is definitely not "assign". This is a serious problem, you need to figure out why this has been assigned incorrectly. There's no way (for us) to tell from the numbers that they are UTM, they could be VicGrid (or anything, but presumably you can confirm what they are). scruss' answer is the right one, as long as 28355 is actually correct.
Sep
25
comment How to cluster Raster data
Are you looking at NSIDC sea ice concentration? I think this question needs more concrete details.
Sep
21
comment QGIS 1.8 will not load world file
Try renaming it .wld, but otherwise can you post your .jpgw file and provide some details about the .jpg file, and more detail about what you do and the problem? "words to that effect" is not very useful.
Sep
19
comment gdallocationinfo is not recognized
FWTools is hopelessly out of date, and presumably predates this utility. Use OsGeo4W to replace your install with the gdal commandline tools.
Sep
18
comment In a ROMS model, how can a get the time series data for a parameter using a lat/lon point?
It's a bit rich to ask this without any supporting background in the question itself. Why don't you put in the preparation required and an example data set and the code to get to the point where the question is relevant?
Sep
16
comment Proximity in space and time
This is pretty easy in R, just loop over each point and use sp::spDistsN1 to get the distance to points within the date range, do the test. If you have some example or dummy data it would be quick enough to illustrate.
Sep
15
comment Is there a world projection that looks like a 3D globe?
Orthographic: en.wikipedia.org/wiki/Orthographic_projection_(cartography) In PROJ.4 it's called "ortho".
Sep
4
comment R - Plotting shapefile with geographical (raster) data
Try adding information to your question and removing noise, what are x.pixel,y.pixel etc., these are not helpful and nothing is added.
Sep
3
comment R - Plotting shapefile with geographical (raster) data
try r <- rasterFromXYZ(d) where d is a data.frame or matrix with columns lon,lat,precip
Sep
3
answered R - Plotting shapefile with geographical (raster) data