comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: on reading NCDF files

Re: on reading NCDF files
type: item
description: In article <3ee6ff80.0401192300.534dc5b1@posting.google.com>, "Sangwoo" <leesw@astro.snu.ac.kr> wrote: > Hi everyone!<snip>... > I wonder if there's any way to figure out > all details of the included variables from an NCDF file directly. NetCDF wouldn't be terribly useful if you needed to know what was in there before using it :) result=ncdf_inquire(cdfid) ; result is a struct containing the number of variables, dimensions and attributes var=ncdf_varinq(cdfid, varid) ;where 0 <= varid < result.nvars ;var is a struct containing the variable name, datatype, dimensions, etc. ncdf_varget, cdfid, varid, data ;gets the data, as ever. There's also NCDF_DIMINQ which does similar things for the dimensions in the file. Chris.
creator: Chris Lee
date: 2004-01-20T09:35:11-00:00

Re: on reading NCDF files
type: item
description: Sangwoo wrote: > Hi everyone! > > I'm gonna read a NCDF file. It may contain several variables within > itself. When I extract a variable named "image", the procedure is as > follows: > > cid=ncdf_open('test.nc') > vid=ncdf_varid(cid,'image') > ncdf_varget,cid,vid,image > > But suppose I don't know the name of each variable unfortunately. Is > there any way to figure out the details of the included > variables(name, dimension, etc.)? The second command fails when I put > a wrong variable. And is there any way to read the included variables > all at once? (something like /all keyword) > > I wonder if there's any way to figure out all details of the included > variables from an NCDF file directly. Dear Sangwoo you could try our read_ncdf function. http://www.fz-juelich.de/icg/icg-i/idl_icglib/idl_source/idl _html/dbase/read_ncdf_dbase.pro.html This routine reads all international defined attributes and some more. The attributes has to be defined in a definition routine, e.g. def_icg. A different diffinition could be given with a keyword: def_struct you could call it this way x=read_ncdf(file) reads everything of parameters x=read_ncdf(file,[var1,var2]) var1 ... short_name of parameter, all coordination parameters are readed too x=read_ncdf(file, /raw,/as_pointer) result is a structure all values are pointer, no valid index vectors are creaeted no scale_factor no add_offset is used. x=read_ncdf(file,/status) additional info about definition of varibales is added There are more keywords available. And there are lots of routines for the ICG-DATA-STRUCTURE in our libray at http://www.fz-juelich.de/icg/icg-i/idl_icglib/idl_lib_intro. html regards Reimar
creator: R.Bauer
date: 2004-01-20T13:57:40-00:00