Parallel Computation of Short IPB Systems

Table of Contents

• Overview
• Installation Guide
  • Prerequisites
  • Environment Setup
  • Installation Steps
• Quick Start
  • Using Setup Script
  • Manual Setup
• Example Usage
• Troubleshooting
• Additional Resources

Overview

This package provides a framework for automating the reduction of Feynman integrals using Integration-by-Parts (IBP) identities and sector decomposition. It transforms sector structures into directed acyclic graphs (DAGs) and generates Petri net representations for parallel computation using GPI-Space.

Installation Guide

Prerequisites

Required System Packages:

sudo apt update
sudo apt install -y build-essential ca-certificates coreutils curl \
    environment-modules gfortran git gpg lsb-release python3 \
    python3-distutils python3-venv unzip zip

Environment Setup

1. Create and set up working directory:

mkdir -p ~/singular-gpispace
cd ~/singular-gpispace

2. Set environment variables (add to ~/.bashrc for persistence):

echo 'export software_ROOT=~/singular-gpispace' >> ~/.bashrc
echo 'export install_ROOT=~/singular-gpispace' >> ~/.bashrc
source ~/.bashrc

Installation Steps

1. Install Spack:

# Clone Spack
git clone https://github.com/spack/spack.git $software_ROOT/spack

# Switch to stable version
cd $software_ROOT/spack
git checkout releases/v0.23

# Initialize Spack
. $software_ROOT/spack/share/spack/setup-env.sh

# Bootstrap Spack
spack spec zlib

2. Install gspc-feynman:

# Add package repository
git clone https://github.com/singular-gpispace/spack-packages.git $software_ROOT/spack-packages
spack repo add $software_ROOT/spack-packages

# Install package
spack install gspc-feynman

3. Configure Environment:

# Set environment variables
export GSPC_FEYNMAN_INSTALL_DIR=$(spack location -i gspc-feynman)
export GPI_SPACE_HOME=$(spack location -i [email protected])
export GSPC_HOME=$GPI_SPACE_HOME
export SINGULAR_INSTALL_DIR=$(spack location -i [email protected])
export GSPC_FEYNMAN_EXAMPLES_DIR=$GSPC_FEYNMAN_INSTALL_DIR/share/examples
export SINGULARPATH=$GSPC_FEYNMAN_INSTALL_DIR
export LD_LIBRARY_PATH=$GSPC_HOME/lib:$GSPC_FEYNMAN_INSTALL_DIR/lib:$LD_LIBRARY_PATH

Quick Start

Using Setup Script

The recommended way to start is using the provided setup script:

$GSPC_FEYNMAN_INSTALL_DIR/libexec/setup.sh

After pressing Ctrl+C to stop watching the monitor:

# Change to working directory
cd $software_ROOT

# Load Singular
spack load [email protected]

# Start Singular
Singular

Manual Setup

If you prefer manual setup:

# Create logs directory
mkdir -p $software_ROOT/logs

# Get GPI-Space binary path
GPISPACE_BIN=$(spack location -i [email protected])/bin

# Start monitor with logging
[ -f $software_ROOT/logs/monitor.txt ] && rm $software_ROOT/logs/monitor.txt
cd $GPISPACE_BIN && ./gspc-logging-to-stdout.exe --port 9876 >> $software_ROOT/logs/monitor.txt 2>&1 &

# Monitor the output
tail -f $software_ROOT/logs/monitor.txt

Example Usage

LIB "templategspc.lib";

// Configure GPI-Space
configToken gc = configure_gspc();
gc.options.tmpdir = "tempdir";
gc.options.nodefile = "nodefile";
gc.options.procspernode = 4;
gc.options.loghostfile = "loghostfile";
gc.options.logport = 9876;

// Define graph structure
ring R = 0, x, dp;
list v = list(1, 2, 3, 4, 5, 6);  // vertices
list e = list(
    list(6, 1),    // edge 6->1
    list(4, 6),    // edge 4->6
    list(1, 2),    // edge 1->2
    list(3, 5),    // edge 3->5
    list(4, 3),    // edge 4->3
    list(2, 5),    // edge 2->5
    list(5, 6),    // edge 5->6
    list(1),       // external leg 1
    list(2),       // external leg 2
    list(3),       // external leg 3
    list(4)        // external leg 4
);

// Define target integrals
list targetInt = list(
    list(1, 1, 1, -1, -3, -1, -1, -1, -1),
    list(1, -1, 1, -1, -3, -1, -1, -4, -1)
);

// Compute sector decomposition
list L = v, e, targetInt;
def re = gspc_feynman(L, gc);

Troubleshooting

Common Issues

1. Monitor Not Starting

   • Check if port is in use:

     netstat -tuln | grep 9876

   • Check log file:

     cat $software_ROOT/logs/monitor.txt

   • If "Connection refused" errors in Singular:

     # Kill any existing monitor processes
     pkill -f gspc-logging-to-stdout.exe
     
     # Start monitor with proper environment
     export software_ROOT=~/singular-gpispace
     mkdir -p $software_ROOT/logs
     GPISPACE_BIN=$(spack location -i [email protected])/bin
     cd $GPISPACE_BIN && ./gspc-logging-to-stdout.exe --port 9876 >> $software_ROOT/logs/monitor.txt 2>&1 &

2. Module Loading Issues

   # Reload modules
   spack load [email protected]
   spack load [email protected]
   spack load gspc-feynman

3. SSH Connection Issues

   # Test SSH connection
   ssh localhost echo "SSH connection successful"
   
   # Regenerate SSH keys if needed
   ssh-keygen -t rsa -b 4096 -N '' -f ~/.ssh/id_rsa
   ssh-copy-id -f -i ~/.ssh/id_rsa localhost

4. [email protected] Not Found If you encounter an error indicating that [email protected] is not found:

   # Run checksum command
   spack checksum [email protected]
   
   # When prompted, select version and press 'c' to checksum
   
   # Edit the package file
   spack edit gpi-space
   
   # Ensure it contains:
   version("24.12", sha256="9cd97b8e41b4494c14a90afff6b801f9cf3b5811205e39c33a481ab09db59920")

   Then restart from Install gspc-feynman

Environment Verification

# Check environment variables
echo "SINGULAR_INSTALL_DIR: $SINGULAR_INSTALL_DIR"
echo "GSPC_FEYNMAN_INSTALL_DIR: $GSPC_FEYNMAN_INSTALL_DIR"
echo "GSPC_FEYNMAN_EXAMPLES_DIR: $GSPC_FEYNMAN_EXAMPLES_DIR"
echo "SINGULARPATH: $SINGULARPATH"

# Check file permissions
ls -l $software_ROOT/tempdir
ls -l $software_ROOT/nodefile
ls -l $software_ROOT/loghostfile

Additional Resources

• GPI-Space Documentation
• Singular Documentation
• Spack Documentation

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

Apache License 2.0 - see LICENSE file