Reputation
475
Top tag
Next privilege 500 Rep.
Access review queues
Badges
3 10
Newest
 Yearling
Impact
~30k people reached

Feb
10
comment How can a make a netcdf with subgroups smaller?
Ah, the the lon /dimension/ is 4500 long in index space, so try a -d lon,0,4500,10 (or -d lon,0,4499,10 ?) to get the full 0-360 degree range in the lon /variable/ space. The 29.2 value is near 360degrees*360index/4500index= 28.8degrees. What I meant by the georeferencing being right is that the lon coordinates are subsampled by the same procedure as the rest of the varaibles. The lon,lat coordinates will still match the data, whether you are looking at 1 out of 10 of the first 8% of the dataset or 1 out of 100 of the entire set of longitiudes.
Jan
19
comment How does Resampling raster work at corner cells?
My understanding comes from the Alvy Ray Smith 1995 "A Pixel is not a little square" alvyray.com/Memos/CG/Microsoft/6_pixel.pdf and the bilinear interpolation algorithm, (following en.wikipedia.org/wiki/Bilinear_interpolation ). For bilinear interp outside of the bounds of square defined by the corner's centers, either 2 or 3 of the inputs the the bilinear interp are undefined, so one either modifies the formula to deal with missing data, (or equivalently, fills in the missing data with the nearest data point)
Jan
15
comment Write EXIF coordinates to images based on common field
If you are interested in points, you can post your solution as an answer and accept it.
Jan
15
answered Over writing one large DEM over another in QGIS or GDAL
Jan
14
answered How does Resampling raster work at corner cells?
Jan
13
comment How can I add 3 axis orientation information to my photos?
Since the OP mentions an easy ExifTool script, Exiftool has an example of a couple more user-defined GPSPitch and GPSroll tags in the sno.phy.queensu.ca/~phil/exiftool/config.html page. If you can write an app on a phone to log these while snapping pictures, you'd be done.
Jan
13
comment How to parse EXIF GPS information to lat,lng decimal numbers
According to the exif standard, there are three "rational" fields for each, containing degrees, minutes, and seconds. exiftool normalizes imporoper decimal degrees into D,M,S while assigning these values, (exiftool -GPSLongitude="0.5 90 63.12345" junk.jpg" -> GPS Longitude: 2 deg 1' 3.12" W") So if you need decimal degrees, you do dd=x0+x1/60.+x2/3600. and could ignore the non-normalization.
Jan
13
comment Write EXIF coordinates to images based on common field
in what format are the new coordinates? I'd consider looping over the image names, looking up the coordinates for the matching name, and then modifying the files with exiftool.
Dec
7
awarded  Yearling
Dec
7
answered How to change time zone for netcdf file
Nov
21
comment How can a make a netcdf with subgroups smaller?
How so? It should sample the lon variable/dimension with the same hyperslabbing, leaving the corresponding coordinates for each point.
Nov
19
comment How can a make a netcdf with subgroups smaller?
Oh -- you might make sure your whether your sampling is in variable space or in index space. I think it is in index space, but I'm not sure.
Nov
19
comment How can a make a netcdf with subgroups smaller?
Yep. You could sample the latitudes as well.
Nov
19
revised Reading netcdf sub variables and convert to raster grid in r
highlight some features of the dataset
Nov
19
comment Reading netcdf sub variables and convert to raster grid in r
No thanks. From browsing the output of 'nc', it looks like these are individual point observations, each with a corresponding latitude, longitude, and time. Subsetting and interpolating random point data to a regular grid is a problem with many solutions.
Nov
19
comment How can a make a netcdf with subgroups smaller?
Please do a 'ncdump -h hycom_glb_911_2015110200_t000_uv3z.nc' so we can tell what the variables and dimensions are.
Nov
19
answered How can a make a netcdf with subgroups smaller?
Nov
19
comment Reading netcdf sub variables and convert to raster grid in r
'file' and 'var' are both pre-existing functions. You might consider using other names.
Nov
19
comment Reading netcdf sub variables and convert to raster grid in r
I used library(ncdf4). I edit my code a bit and added the md5sum of the file I opened, and some summary() info on the result.
Nov
19
revised Reading netcdf sub variables and convert to raster grid in r
edited body