Re: Efficiency of NetCDF reading and writing functions.

• To: Timothy Hume <tim.hume@xxxxxxxxxxxxxx>
• Subject: Re: Efficiency of NetCDF reading and writing functions.
• From: Russ Rew <russ@xxxxxxxxxxxxxxxx>
• Date: Wed, 18 Sep 2002 16:44:20 -0600

Tim Hume wrote:

> I was wondering about how efficient the NetCDF reading and writing
> functions are. In particular, it should be possible to use the NetCDF
> functions:
> 
> nc_get_varm_type and
> nc_put_varm_type
> 
> to read and write any arbitrary array of NetCDF data. My question is, is
> it less efficient to use the put/get_varm functions than using one of the
> more "specialised" functions (put_var1, put_var, put_vars, put_vara etc)?

In the C interface, the vars (strided) interfaces are implemented in
terms of the varm (mapped) interfaces, which are implemented using the
vara (array) interfaces.

The mapped interfaces don't offer any significant efficiency
advantages over the more specialized interfaces, but may offer
convenience if they do what you want.  They have not been widely used,
and were not implemented in the newer object-oriented interfaces, such
as for Java and C++.

--Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
russ@xxxxxxxxxxxxxxxx                     http://www.unidata.ucar.edu

• References:
  • Efficiency of NetCDF reading and writing functions.
    • From: Timothy Hume