1,954 reputation
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bio website staff.acecrc.org.au/~mdsumner
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visits member for 4 years, 1 month
seen 2 hours ago

R, Manifold, GDAL, also interested in Python, topojson/D3 and NetCDF/HDF


1d
comment Software for opening .img files
.img is not enough to identify a format, it is ambiguous at best. Note that some software ignore the extension,or only use it as part of the evidence, and some formats ship without an extension at all
Dec
21
comment Runnig of LSMA method in ENVI sotware
What is runnig, lsma, envi and ppi? Details please.
Dec
20
comment Is there an R equivalent of NEAR in ESRI ArcGIS?
What nearest neighbour packages? kdtree in nabor is likely to be the most efficient, but if you need ellipsoid distances you can roll your own with spDistsN1 in sp.
Dec
6
comment Raster to polygon using R
What has this got to do with R? I would focus on that, you give no details on the crash, your computer, or the code.
Dec
1
comment is esri-leaflet officially an esri project on github?
And title-case fixes that? :)
Dec
1
comment How to merge an excel file with a shapefile in r
Provide the code you are using and more detail about the files. This is pretty straightforward using tools in sp. Also, generally it's better to use rgdal::readOGR rather than maptools::readShapePoly since you'll also get projection metadata automatically (if it's there).
Nov
26
comment How to use shapefile in QGIS on Debian?
Does your ssh client allow X-forwarding? It's the -X argument to ssh, or some setting on the interface, or as it states the configuration of your client DISPLAY.
Nov
26
comment How to use shapefile in QGIS on Debian?
I install xorg-dev on Ubuntu, then ensure my ssh client enables X-forwarding, then qgis will start. I don't use Debian but it will have a similar way.
Nov
24
comment Assign CRS to shapefile in R
it is proj4string not projection (the latter is in raster)
Nov
22
comment gdalwarp with NETCDF files
Ultimately the GCPs are those long/lat arrays, but you may not need any "warping" to re-establish the original LCC projection. Can you point to an example file somewhere? If the creators have smashed/lost the original projection sometimes you can recover with a bit of detective work, or it may be as simple as re-assigning it with gdal_translate's arguments "-a_srs" and "-a_ullr". If you think the data is in LCC but it ships with longlat arrays, then there's a disconnect in there somewhere.
Nov
19
comment Do rasters other than “north up” exist in the wild?
North-up is different to variations in affine transform conventions, they are totally different concepts. Many projections are radial about a pole, besides many other counter examples to the OP
Nov
18
comment How to prevent cross-world lines in ggplot world map?
Why put the example elsewhere?
Nov
18
comment How to prevent cross-world lines in ggplot world map?
but try the argument "breakAtDateLine" for the gcIntermediate function (and please provide reproducible code - it's just not useable as is).
Nov
18
comment How to prevent cross-world lines in ggplot world map?
It's no easier in base though really. The fundamental problem is described well here bost.ocks.org/mike/example and here vimeo.com/106198518. Any fix in R depends heavily on the data you want to use the way you want to plot.
Nov
15
revised Export band names with NetCDF file in R
added 3601 characters in body
Nov
14
answered Export band names with NetCDF file in R
Nov
13
comment Mapping NetCDF CF Mercator parameters to GDAL
Check this out: remotesensing.org/geotiff/proj_list/mercator_1sp.html Notably "PROJ.4 does not support a latitude of natural origin other than the equator", otherwise I thinkyour presumptions are right. (Apart from ignoring false easting/northing - you cannot do that if not zero, but it's a trivial adjustment). Anyway, in my experience it's rare for NetCDF to explicitly store non-longlat explicitly, so keen to learn more if you can share more details from the header.
Nov
10
awarded  Yearling
Nov
6
comment Count values greater than 0 in SpatialPolygonsDataframe R
Quite. There's no room for more than one "layer" in a SpatialPolygonsDataFrame in my sp-dictionary. I think you mean nrow(spolydf) > 100. Yeah? Please clarify the rest I cannot make sense of it.
Nov
2
comment Prior art on rhumb line and great ellipse areas?
Ok thanks, we are on the same page at least. I don't see a problem with this, it's a limitation in most systems that the "curve" must be stored as an approximation rather than be generated on the fly from a rhumb or gc rule. I am interested to see if there will be any answers.