Hi Alex: 1) The first time will be slow because it needs to write an index. Subsequent opens should be fast. Version 4.3 will be significantly faster on subsequent opens. 2) Still, 2 secs for 35K is way too slow. Are you sure of that timing? 3) The process is I/O bound, not CPU. So if those timings are real, you should look there. John > Good afternoon Sean, > > Thanks again for the source and the advise. It is much appreciated and got > me up and running. > > Just want to ask you, based on your experiencem My grib files are about > 35K, only have lat/long/time/temp, I am running on the 3.7GHz quad core > 64bit box with plenty on memory, but it still takes about 2 seconds to open > the file and get a data set per file. > > Any advise on how to expedite the process? Is there an option to utilize > the processor more? > > Thank in advance, > > Alex. > > address@hidden> wrote: > > > Greetings Alex, > > > > I've attached a sample java program that goes to our publicly accessible > > data server and grabs temperature value from the CONUS GFS 80KM grid, and > > then prints that value to the screen. To extend this simple program to data > > into an array, which is what you would want to do, check out the following > > site: > > > > https://www.unidata.ucar.edu/software/netcdf-java/tutorial/NetcdfFile.html(particularly > > the section on "Manipulating data in Arrays") > > > > and > > > > > > https://www.unidata.ucar.edu/software/netcdf-java/tutorial/NetcdfDataset.html(NetcdfDataset.openFile > > is what the example java file uses) > > > > as well as the general info in the tutorial here: > > > > https://www.unidata.ucar.edu/software/netcdf-java/tutorial/index.html > > > > Cheers! > > > > Sean > > > > > Hey, > > > > > > Thanks for the links will check it out. > > > > > > I am downloading files from the website. Raw data is in grib/grib2 > > format. > > > Now that we on the topic, can you point me to the java api for random > > > access directly on the server, so I can only reap out the fields I need, > > if > > > that is possible at all. > > > > > > Thanks in advance, Alex. > > > > > > > > > address@hidden> wrote: > > > > > > > Greetings Alex, > > > > > > > > > Hi Sean, > > > > > > > > > > Thank you very much for the reply. To answer your questions. > > > > > > > > > > Yes, I am reading gfs data. > > > > > > > > Where do you get the data? From a website, your own model run? Is the > > raw > > > > data format in netCDF, grib? > > > > > > > > > I am planning to compare the runs, once the data extracted. > > > > > > > > > > I would like to keep the program 100% java if possible, which is > > reading > > > > > the files, processing and saving. > > > > > > > > > > > > > Keeping things 100% java should not be a problem. It may help to read > > > > through some example programs ( > > > > http://www.unidata.ucar.edu/software/netcdf/examples/programs/) using > > > > netCDF-Java to read files and access data, especially the following > > example > > > > ( > > > > > > http://www.unidata.ucar.edu/software/netcdf/examples/programs/Sfc_pres_temp_rd.java > > ). > > > > If you are able to open your files and read data from the variables, it > > > > should be relatively straightforward to dump the data you need to a > > format > > > > of your choice. > > > > > > > > Cheers, > > > > > > > > Sean > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > Alex Friedman > > > > > > > > > > address@hidden> wrote: > > > > > > > > > > > Greetings Alex, > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > I am very new to the api. > > > > > > > > > > > > Welcome to netCDF-Java! > > > > > > > > > > > > > My ultimate goal is to translate raw gfs data > > > > > > > into a table in memory with 3 columns long, lat and temp. > > > > > > > Is this doable using java api? Could you point me to the right > > > > > > direction? > > > > > > > > > > > > > > I am parsing the file fine and creating the dataset, I am having > > > > problems > > > > > > > understanding how I can output the table and what classes should > > I > > > > use. > > > > > > > > > > > > If I understand correctly, you wish to extract long, lat, and > > temp, and > > > > > > save the data in something like a comma delimited ASCII file? This > > is > > > > > > indeed possible; however, for clarification purposes, what is your > > > > planned > > > > > > use for the data once you have extracted long, lat, and temp? Also, > > > > where > > > > > > are you obtaining the GFS data? I ask because their may be a very > > easy > > > > way > > > > > > to get what you desire. > > > > > > > > > > > > Cheers! > > > > > > > > > > > > Sean > > > > > > > > > > > > > > > > > > > > Thank you in advance, > > > > > > > > > > > > > > Alex. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > > > > =================== > > > > > > Ticket ID: MIY-264031 > > > > > > Department: Support netCDF Java > > > > > > Priority: High > > > > > > Status: Open > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > > =================== > > > > Ticket ID: MIY-264031 > > > > Department: Support netCDF Java > > > > Priority: High > > > > Status: Open > > > > > > > > > > > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: MIY-264031 > > Department: Support netCDF Java > > Priority: High > > Status: Open > > > > > > Ticket Details =================== Ticket ID: MIY-264031 Department: Support netCDF Java Priority: High Status: Closed
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