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bio website staff.acecrc.org.au/~mdsumner
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visits member for 3 years, 5 months
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R, Manifold, GDAL, also interested in Python, topojson/D3 and NetCDF/HDF


Mar
8
comment Making a georeferenced PDF or GeoTIFF from jpg+jgw using GDAL for Avenza PDF Maps
You at least need to add the coordinate system with -a_srs maybe that will help Avensa? Can you include the output of gdalinfo for each stage?
Mar
8
comment Per-pixel calculations on a raster stack using GDAL
I will when you add sufficient detail about what you are doing and how. :)
Mar
8
comment Raster: mosaic first, or project first?
I don't the second option makes any sense, there will be edges broken everywhere. Option 3 is just a way of achieving 1. Do a test with 3 and then commit that VRT to a tiled and compressed GeoTIFF if the performance is too slow.
Mar
8
comment Per-pixel calculations on a raster stack using GDAL
It might be worth looking closer to find a faster way in R/raster, there are a few ways to do it and the details matter. Happy to do that perhaps outside this q if you want
Mar
6
comment How can I correct a .pgw file for a PNG image?
There's obviously no coordinate system metadata so I would check that the right one is assigned or in-use when you load it. It is probably being displayed with an assumed projection that is wrong. (Best to use a spatial format like GeoTIFF that can store all this stuff but hardly anyone does unfortunately)
Mar
6
comment gdal2tiles generates small picture inside 256x256 tile
This works if I do this, with no -z argument: python gdal2tiles.py -p raster ibcso_background_hq. tif ibcsoraster I can maybe have a closer look later, but it might be something to do with how the levels interact, but otherwise def a bug in the script.
Mar
3
comment gdal2tiles generates small picture inside 256x256 tile
Can you make a simple example, or at least give more details on the kind/s of source image and the actual commands used? Are you transforming somehow from the source because afaik that is not going to work in a single step
Mar
3
comment What is the easternmost point in the US?
What about the Amundsen-Scott base on the South Pole?
Feb
25
comment What format to store/use four band Raster data
I still think GeoTIFF is the best, it is hard in software design to cover all possibilities in read/view software and provide a sensible default, but anything worth using will allow you to change a default interpretation. Perhaps this q should be about the specifics of that for your targets?
Feb
25
comment How to convert a .tif with .tfw to a GeoTiff?
You also need to ensure that a coordinate system is set with -a_srs otherwise it is kind of a malformed GeoTIFF.
Feb
17
comment What is the latest version of R that supported gpclib?
3.0.2 plus 10 chars for so
Feb
15
comment Dates are off when opening netcdf file in R
ISOdatetime(1950,1,1,0,0 ,0,tz="GMT")+508008 * 3600 # [1] "2007-12-15 GMT"
Feb
13
comment How to load Georeferenced Scanned Maps in R
Best to project the vector to the raster rather than the other way around. Plus we need details, see ?projectRaster for options (assuming you used that)
Feb
12
revised How to load Georeferenced Scanned Maps in R
overplot
Feb
12
answered How to load Georeferenced Scanned Maps in R
Feb
10
comment how to create CF-compliant NetCDF from ESRI Grid?
Not sure I was born when that version came out
Feb
8
comment Driver Error : DTM to Raster using GDAL_GRID
I would use ogrinfo on the mdb alone to check that you can access that correctly
Feb
8
comment how to create CF-compliant NetCDF from ESRI Grid?
Please include the GDAL version.
Feb
7
comment how to create CF-compliant NetCDF from ESRI Grid?
I think you should demonstrate your evidence for this and what version of GDAL you are using and how you use it, " I know the netcdf output option is definitely not CF compliant" - it's not something I've looked at in detail but a lot of work has been done to improve NetCDF in GDAL in the last few years.
Feb
7
comment how to create CF-compliant NetCDF from ESRI Grid?
GMT is a really weird variant that drops the array dims and requires the client to reinstate it, I doubt that it's what you want