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getfilevardimsizes

Returns the dimension sizes of variable on a supported file.

Prototype

	function getfilevardimsizes (
		thefile [1] : file,    
		varname [1] : string   
	)

	return_val [*] :  integer or long

Arguments

thefile

A reference to a file, created using addfile or addfiles. Thus, it must be a supported file format.

varname

The string name of the variable whose dimension sizes are desired.

Return value

Returns a one dimensional array of dimension sizes for a file variable. In versions 5.x or earlier, this function always returns an integer array. In versions 6.0.0 or later, this function may return a long array. See below.

Description

This function works just like dimsizes, but for file variables. This function should be used rather than dimsizes when the variable is in a file. The dimsizes function is very inefficient to use on file variables because it reads in the entire variable. The getfilevardimsizes function should be used exclusively when querying the dimensionality of variables in files.

As of version 6.0.0, this function will return type "long" if any of the individual dimension sizes or the product of the dimension sizes is greater than or equal to 2 GB.

Note: This function is exactly the same as filevardimsizes. It was created for consistency purposes.

Examples

Example 1 Consider a netCDF file where "ncdump -h Tstorm.nc" yields:

netcdf Tstorm {
dimensions:
        timestep = 64 ;
        lat = 33 ;
        lon = 36 ;
        timelen = 20 ;
variables:
        float t(timestep, lat, lon) ;
                t:_FillValue = -9999.f ;
        int timestep(timestep) ;
        float lat(lat) ;
        float lon(lon) ;
        char reftime(timelen) ;
                reftime:units = "text_time" ;
                reftime:long_name = "reference time" ;
}

  a    = addfile("$NCARG_ROOT/lib/ncarg/data/cdf/Tstorm.cdf","r")

  dimt = getfilevardimsizes(a,"t")  
  print(dimt)

This produces the following output: