1,944 reputation
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bio website staff.acecrc.org.au/~mdsumner
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visits member for 4 years
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R, Manifold, GDAL, also interested in Python, topojson/D3 and NetCDF/HDF


Jun
8
comment libgdal1 and libgdal1h conflict
scigeo.org/articles/…
Jun
6
comment How should “consumer oriented” geographical applications be called?
It's just software for basic data. We've been held back by crazy legacies for so long we think it's normal not to have access to basic tools. I think you're struggling to name this because it just should be part of the normal everyday habits of people to use "map stuff". Things are changing.
Jun
2
comment How can I take a large netcdf and convert it to interpolated values in a different set of coordinates?
Use extract with your lonlat points as SpatialPoints, extract will transform automatically. But there is a lot here to unpack if you are not usedto it
Jun
2
comment How can I take a large netcdf and convert it to interpolated values in a different set of coordinates?
Use the raster package, you can reproject/resample the whole thing in one step using raster's cunning tricks. But, I would question why you really need to reinterpolate the thing, do you really need to do that?
Jun
2
comment Is there a way to write single bands raster from multi-band layer faster in r?
I don't think there's any need to unstack, just use s <- stack("multiLayerRaster.tif"). Don't call your object "stack". Loop on seq_len(nlayers(s)) and you'll have to add .tif to the file name otherwise it will be "native raster" format. There are also options to tile and compress tifs.
Jun
2
comment Plotting two shapefiles using R?
Read the files in with rgdal::readOGR and figure out their projection with proj4string(). Plot them together using plot(...,xlim=,ylim=) with appropriate ranges and add=TRUE. The map() data defaults to longlat so you need to transform one to the other.
May
31
comment Creating TopoJson from shapefile with the Shape Escape (shpescape)
Presumably your problem is due to the files being archived. Try unzipping and what if you use topojson instead?github.com/mbostock/topojson/wiki/Command-Line-Reference
May
31
comment Creating TopoJson from shapefile with the Shape Escape (shpescape)
"shpescape", genius
May
30
comment How to create GeoTiff file from .h5 file?
It depends whether the coords are regular, rectilinear or curvilinear. Yes, easy if regular, ootions available for the other. Try gdal_translate file.h5 out.tif as a hopeful startbut note the structure possible in h5 is more general than gtiff. It depends on the file and the intention
May
29
comment How to batch generate thumbnails of raster layers with R?
The difference is the defaults for asp.
May
22
comment Changing tracks to vectors in a grid
We can look at doing this with R easily enough if you can switch teams. But, what does sum mean for a direction, please expand on *why" you would do this? What is the goal?
May
21
comment Creating custom projections with Proj4
grokbase.com/t/gg/d3-js/1342xtbkqt/…
May
14
comment How can I access the subdatasets of a grib file with gdalwarp?
Tell us what gdalinfo reports for the file. Subdatasets need the "PREFIX:filename:etc" incantation, bands are specified with -b.
May
12
comment Is it possible to use polygons to create heatmaps?
Can you provide a definition for heatmap?
May
7
comment Opening netcdf in arcmap as a raster with uneven coordinate spacing?
According to tests here EASE grid is actually Cylindrical Equal Area but obviously it ships with lon lat arrays. stackoverflow.com/questions/22785860/… This is painful albeit very common. I would ask the data providers how to do what you want, though in my experience reconstructing the native projection is the way to go. I don't know how to use Arcmap, but if it can make it ignore the irregular coords and then assign the cea georeferencing. Not much help sorry
Apr
29
comment Convert SpatialGridDataFrame in to polygon shapefile in R
Use raster in raster package to create a RasterLayer, this can deal with 'raster attribute tables' see ?ratify. Also ?RasterToPolygons.
Apr
23
comment converting coordinates from unusual DMS format to decimal
This is FAQ 7.31 format(abs(-8.01 - trunc(-8.01))*100, digits = 16)
Apr
23
comment converting coordinates from unusual DMS format to decimal
Well it depends on the need, my function can be changed to be more flexible, but if you have numeric input there are many more cases to catch. It should not be numeric ever if the format is taken seriously, perhaps Excel is the main problem.
Apr
23
comment converting coordinates from unusual DMS format to decimal
Well if you are coercing numeric to character you'll need to get the formatting right, as it stands with your edit the question is kind of open-ended now.
Apr
23
revised converting coordinates from unusual DMS format to decimal
sp comparison for round trip