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Loading Many Polygon files

Austen Blair, modified 3 Years ago.

Loading Many Polygon files

Youngling Posts: 1 Join Date: 4/26/17 Recent Posts
Hello everyone,

I'm trying to run a coastal model with many levees/defenses (more than 10000) of varying heights. The levees are initialized using a single Fixed Weir pli file.Levees are separated with -999 values.

In different scenarios, I want to 'fail' or lower some of these levees. I'm currently doing that using a separate pli and tim file for each failed levee in the external forcing file as a dam level forcing.
This has been working fine so far, but I recently ran a scenario in which over 1000 levees need to fail. I receive an error code that there are no available file unit identifiers, and the run stops.

I’ve traced the apparent source of the error to the script ec_support.f90, specifically the function ecSupportOpenExistingFile. The ‘maxFileUnits’ parameter here is defined elsewhere as 1000, limiting the number of files one can open.

Is there a reason for this limitation? Could this be set higher to allow for more files to be loaded?

Alternatively, is there a way I can define multiple failed levees in a single pli file, and have them lower to different levels controlled by a single timing file?

Erik de Goede, modified 3 Years ago.

RE: Loading Many Polygon files (Answer)

Youngling Posts: 15 Join Date: 1/7/11 Recent Posts
Dear Austen,

The specified maximum number of open files (1000) is a safe estimate of what most operating systems are capable of handling. The maximum number of open files depends on the operating system. You might try to increase this number at your own risk. Probably there is an upper limit of 2048 files. The alternative that you propose will lead to programming difficulties, because time series need to be read simultaneously during a simulation, keeping track of the last read position in the file for that specific time series.

Erik de Goede (on behalf of a colleague)