Reading a NetCDF file with Matlab and R



file_name = '/matlab/R2012a/toolbox/matlab/demos/';
var_name = 'temperature';
group_name = '/grid2/';
tmp = var_name;  % or tmp = group_name
% Display global information about a netcdf file
% About a variable or a group
ncdisp(file_name, tmp);
% In the specified format 'full' or 'min'
ncdisp(file_name, tmp, 'min');    

% Get information about a netcdf file info = ncinfo(file_name) % About a variable var_info = ncinfo(file_name, var_name) % About a group gr_info = ncinfo(file_name, group_name)     % Read data from a vraiable of a netcdf file data = ncread(file_name, var_name); % Or % data = ncread(file_name, var_name, start, count, stride)     % Read attribute attr = ncreadatt(file_name, '/', 'creation_date') var_attr = ncreadatt(file_name, var_name, 'add_offset') gr_attr = ncreadatt(file_name, group_name, 'description')


#Intall the NetCDF libraries: sudo apt-get install libnetcdf-dev 
#Install the ncdf package in R: install.packages("ncdf")
filename = "/home/ndiaye/Projets/R/"
var_name = "temperature"
attr_name = "units"
# Open a netcdf file
fid <- open.ncdf(filename, write=FALSE)
# Get a netcdf file info
# Get the variable identifier
var_id <- varid.inq.ncdf(fid, var_name)
# Get the name of a variable id 
my_var_name <- varname.inq.ncdf(fid, var_id)
# Get a file attribute
attr <- att.get.ncdf(fid, 0,"creation_date")
# Get a variable attribute attr_value <- att.get.ncdf(fid, var_name, attr_name) print(attr_value)   # Get the size of a variable size <- varsize.ncdf(fid, var_id) print (size)   # Get dimensions of a variable ndims <- varndims.ncdf(fid, var_id) print (ndims)   # Read data from a netcdf file data <- get.var.ncdf(fid, var_name) print(data)   # Get the variable objet var_object <- var.inq.ncdf(fid,var_id ) print(var_object)   # Get the name from the variable object name <- var_object$name print (name)   # Get variable object units n_attr <- var_object[["units"]] print(n_attr)   # Close a netcdf file close.ncdf(fid)

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