Meshtal file splitter (splitmesh)

Command line tool to separate tallies into individual files for large MCNP meshtal outputs that contain multiple tallies.

Usage: splitmesh <path> [options]

Arguments:
  <path>  Path to input meshtal file

Options:
  -v, --verbose...       Verbose logging (-v, -vv)
  -q, --quiet            Supress all log output (overrules --verbose)
  -h, --help             Print help (see more with '--help')

Split options:
  -t, --tallies <id>...  List of tallies to extract
  -o, --output <name>    Prefix for output files

Note: --help shows more information and examples

Help is printed with the -h flag, and --help will show examples, default values, examples, and any important behaviour.

Overview

Splits up all meshes found in a meshtal file into their individual files.

This is very useful for processing large meshtal files with multiple tallies, or for just reducing file sizes to a minimum for post-processing.

By default, every tally found in the file is splt into individual files.

Install

Download and unpack the latest binary executable release here for running in a terminal/powershell.

Linux/MacOS

Unpack the relevant executable from the latest release.

# Linux
tar -xjf splitmesh-x86_64-unknown-linux-gnu.tar.xz  # Generic linux
tar -xjf splitmesh-aarch64-unknown-linux-gnu.tar.xz # ARM64 Linux

# MacOS
tar -xjf splitmesh-x86_64-apple-darwin.tar.xz       # Intel macOS
tar -xjf splitmesh-aarch64-apple-darwin.tar.xz      # Apple Silicon macOS

And either run from there or add the executable to your $PATH.

./splitmesh -h

Windows

Extract splitmesh-x86_64-pc-windows-msvc.zip from the latest release.

Navigate to this folder and run from powershell.

.\splitmesh.exe -h

This may be set as an alias for convenience.

Set-Alias -Name splitmesh -Value C:\Path\To\Folder\splitmesh.exe

How to choose specific tallies

Use the --tallies option to specify one or more tallies to be separated out. Invalid entries are simply ignored.

# Extract only tallies with ID 104, 204, and 504 from the primary file
splitmesh /path/to/file.msht --tallies 104 204 504

How to change the file names

The name of the output files is appended with the tally number as <output>_<id>.msht. Output defaults to fmesh, but this may be changed.

# Change output file names to "mymesh_<id>.msht"
splitmesh /path/to/file.msht --output mymesh