iousprafa / nctoolbox

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Retrieval of several parameters from one file with single server access ? #65

Closed mariuskist closed 8 years ago

mariuskist commented 8 years ago

Hello,

We currently use nctoolbox to read and store meteorological grib2 data remotely from the CFSR database using MATLAB.

The following filepath is an example OPeNDAP database accessed by nctoolbox

"filepath = http://nomads.ncdc.noaa.gov/thredds/dodsC/modeldata/cmd_pgbh/2006/200604/20060404/pgbh05.gdas.2006040418.grb2;"

The source grib2 file is stored in a ncgeodataset object.

"ds=ncgeodataset(filepath);"

The variable of choice is retrived using a in a geovariable .

"CFSR_variablename = 'Temperature_height_above_ground'; %air temperature in 2 m height variable = ds.geovariable(CFSR_variablename);"

Currently, nctoolbox, recursively, calls files which contains values of a lot of parameters. Amongst these parameters are ~10 required parameters for each file = point of time. This is done to download a time history of the required parameters.

Up to now, I have to access the same file containing 10 required parameters for the same time, 10 times. Once for each parameter. This is because I don't see a way to use "ds.geovariable" for more than one variable. E.g. [variable1,variable2] = ds.geovariable(Temperature_surface,Pressure_surface)

Is there a way to read 10 variables from one source file remotely from an OPeNDAP server with only one server access ? I did not find an example in the documentation but it seems it is also not also not negated.

Best regards Marius Kist