Siphon - A collection of Python utilities for retrieving data from Unidata data technologies.
but now I'm wondering where I'd get a username and password.
I see a "register" button on the unidata homepage.
Is that where I'd get one?
No, since you're using the RDA, you'd need to get it from them. There's a register now link here: https://rda.ucar.edu
I have a question that might be more of a NetCDF4 question, not sure
let's say I make a DataQuery object, call it query
and do a lonlat_point query
and my dataset is a grib2 file
does it look for values based on the nearest grid point?
@dopplershift yeah I really like using this service - siphon in combination with this THREDDs-based technology makes things easier
@dopplershift I got a bunch of grib2s that are filed away actually. And I'm looking at a scalable way of processing them
@dopplershift Maybe this question is better asked to THREDDs at large, but I'm wondering: how much setup is involved with making our own THREDDs instance?
so something that serves grib2 data, has all that XML metadata, etc
like would this tutorial be up to date - fairly straightforward? https://www.unidata.ucar.edu/software/tds/current/tutorial/GettingStarted.html
Greetings @mikebelanger - that tutorial is a bit out of date with respect to the Java and Tomcat instructions. I updated the first part of that page to point to our 5.0 documentation, which includes updated instructions. Same thing with the Security page of the tutorial (https://www.unidata.ucar.edu/software/tds/current/tutorial/Security.html). The rest should be good to go for the 4.6 release, though. If you are most interested in serving GRIB output, then you really should run the 5.0 beta version, as many fixes have been added there that are not available in 4.6. We hope to get TDS 5.0 stable this fall.
oh and thanks for revising that tutorial page too.
@lesserwhirls the 5.0 documentation looks pretty comprehensive! I guess once the grib-loading stuff for 5.0 is firmed up - sections like this will be filled in? https://docs.unidata.ucar.edu/tds/5.0/userguide/grib_files_cdm.html
Hi, is this one of your examples translated to Spanish? https://pybonacci.org/2018/11/27/creacion-de-videos-al-vuelo-en-el-notebook/
@mikebelanger - sorry for the dead link! That's actually a casualty of splitting netcdf-java and the THREDDS Data Server into seperate code bases. That URL will work if you replace /tds/5.0/ with /netcdf-java/5.2/, so https://docs.unidata.ucar.edu/tds/5.0/userguide/grib_files_cdm.html As you run across issues like this with the docs, would you mind opening a github issue over at https://github.com/unidata/tds? Thanks!
Is it possible to use/construct an ncss query to pull a subset of multiple variables at multiple vertical levels? Let's say for example, I want 200 hPa U/V, 500 hPa and 1000 hPa height, and MSLP. Can I get all of that in a single ncss call, or do I have to do multiple ncss calls for each variable/level combo?
I was thinking I could do one ncss call and grab all of the data subset that I need for all of my maps in one call, but I guess not
ideally, I'd like to be able to specify any datetime once, and get the nearest grib2 file to that time.
but so far, I've had to pass in the year, month and day into a catalog URL, in order to get the grib2
for example:
cat = TDSCatalog('https://rda.ucar.edu/thredds/catalog/files/g/ds084.1/2017/20171001/')
if I try something more general, like
cat = TDSCatalog('https://rda.ucar.edu/thredds/catalog/files/g/ds084.1/') I don't get any datasets
like adding the dataset query parameter - I still get no datasets
In that top-level catalog, there are not any datasets, but there are references to other catalogs, which are available from the
.catalog_refs attribute.
@mikebelanger Pretty much, unfortunately since the RDA does not have the data set up (as far as I can tell) using a TDS Grib Collection. Another option for you is to programmatically generate the url, like:
base_url = 'https://rda.ucar.edu/thredds/catalog/files/g/ds084.1/'
dt = datetime(2017, 10, 1)
url = base_url + f'{dt:%Y/%Y%m%d}'
Not completely sure I got the syntax completely correct, but hopefully the idea comes across
I just wanted to make sure I wasn't missing some other method, or some archive feature