This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
>To: address@hidden >From: Mathis Rosenhauer <address@hidden> >Subject: NetCDF F90 Interface >Organization: German Climate Computing Center >Keywords: 200409211415.i8LEFLnJ002151 netCDF Fortran90 Hi Mathis, Wow, I'm surprised no one else noticed that problem, I think it will make a big difference to anyone using the Fortran 90 interface. It looks like the original code never called any of the nc_{put,get}_vara_ functions, but instead just used the nc_{put,get}_varm_ functions with a default map to emulate them, greatly increasing the function call overhead. On behalf of the users of the netCDF f90 interface, thank you! I will put this fix into the 3.6.0 release immediately. --Russ On 21 Sep 2004 09:11:23 -0600, Mathis Rosenhauer wrote: Hi Russ, I am working with some code here which uses the fortran 90 interface of NetCDF. The performance of writing NetCDF files was very poor compared to raw output. The code calls nf90_put_var() with simple arrays, no stride or map. However, it ends up in nc_put_varm_double() which calls nc_put_vara_double() very often. On our NEC SX6 this caused a huge overhead. Attached is a patch which may help other platforms as well - unless I broke something. I stripped out all SX specific stuff. The patch is against 3_6_0-beta3 but should also work with older versions. Cheers, Mathis -- Mathis Rosenhauer http://www.dkrz.de/whois?rosenhauer Application Software Phone: +49 40 41173 395 German Climate Computing Center Pavillon 107 ---559023410-341603450-1095776107=:27017 Content-Type: APPLICATION/x-gunzip; name="patchf90.gz" Content-Transfer-Encoding: BASE64 Content-ID: <address@hidden> Content-Description: Content-Disposition: attachment; filename="patchf90.gz" H4sICDMjUEEAA3BhdGNoZjkwAN1VXW/aMBR9Hr/CD1NJlITGSehKpEmwbp2q tXQa7V6DC04bKTEocSq2X79r8kGwoSXVpKEFCOZe3+ODz4nvPApDZOWfUtTr nTLKZ/PQcoOzwLYeKCduwGnGT7N0dhoObPEh+aqXeEiJdCzLagXxzrFtbNl9 y/GQ4/pe33fsnl1dyLAh3zEMQ11KVHqWPbAcjLDnO32/f6ZUDofI8rB5hgy4 f0DDYQfNaRgxqk3HlwM7wJf34645ZYAadL/f393++Prlbho8kzTofrsaf/45 ur7/ojeLgpuqRCpIgu74QtRsT5/smZ5tphuN6aM908ludLxnOt4xPfGClDKS UCiIQohq0/cYxpt8N1hHIMDWOV3PWZUVP8Wrg2ocbRpBegWxeRv7FPmArjhN GYmzHgTRS8lDTbWrVrjEtoRR+sjBvuu+5q99IA2ruef7rOa6wmpwx3jttUMu 0O6R8sISEePYlCOOEjHRycHYy7ysSymJTWm9KrZ9vQF8vsgfYrpNtIihjoEQ cKaPNJWWqvYY+X4DjICoK96EqiLqdSLA2zAlmy1uRhwlYrbArmnK8hFFvtbY NSdVPrJXvtbgqnyklg+1ky9R5EtekO8QolvgsnyJIl/S9gmpacryJYp8NXa7 A++ZEgDwzpstsxk8+IBr1MiN0/H7/ZcPNqn4oN7peOYAGXDHTvNAixczEt+Q JQw1P4t+Uy0hS10XqY8Ihpqv13PXfVa0NUhtiVL20mlXY7NobiLYX/G1xp5w kvJyfLHIGa/jMIeaNQFTdDeSx/yK8VGakl96xyrMGWe0fA7EEEWhtkxpRhnX sjUGsOVPlB1Ec/JWmgo5QyYnL2xsLTxqsfAziXOaVftO2Rz+c/mjSGkXt9e3 44kO68BOPJEl1SR+IJuJikyJVsAJsDBnMx4t2IZv+4dA9n9L65fGtS0Mbyza uWf7rveq61sZ3jXPwfByBz8iw1c6H5PPK07/wt5/y5zQPtQTugq2sWlVs+OE Vj0ne7VZ/J8YFlrm5jg5JtduETsi6/4BdoaqD40PAAA= ---559023410-341603450-1095776107=:27017-- -- NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.