Usage guide

Sampling of metabolic models is a two-step process.

Generation of warmup points

The generation of warmup points is done through VFWarmup software. After installing the dependencies of VFWarmup, you can build the binaries at the root of VFWarmup using make.

Then call VFWarmup as follows:

mpirun -np nCores --bind-to none -x OMP_NUM_THREADS=nThreads createWarmupPts model.mps SCAIND

Replace the following variables with your own parameters:

  • nCores: the number of non-shared memory cores you wish to use for teh analysis
  • nThreads: the number of shared memory threads within one core
  • model.mps: the metabolic model in .mps format. To convert a model in .mat format to .mps, you can use the provided converter convertProblem.m
  • SCAIND: (optional) corresponds to the scaling CPLEX parameter SCAIND and can take the values 0 (equilibration scaling: default), 1(aggressive scaling), -1 (no scaling). scaling is usually desactivated with tightly constrained metabolic model such as coupled models to avoid numerical instabilities and large solution times.

Example: mpirun -np 2 --bind-to none -x OMP_NUM_THREADS=4 createWarmupPts ecoli_core.mps

You will have to input the number of warmup points to be generated, this is usually a minimum of 2n, where n is the number of reactions in a metabolic model. VFWarmup will perform a minimization and a maximization in each dimension, which means that 2n is the minimum number of samples needed to delienate the solution space.

The ouput file is saved as modelnPtswarmup.csv, with model is the name of the metabolic model and nPts is the number of warmup points generated.

Sampling

The actual GPU sampling is done through ACHR.cu software. After installing the dependencies of ACHR.cu, you can build the binaries at the root of ACHR.cu using make.

Then call ACHR.cu as follows:

./ACHRCuda model.mps warmuppoints.csv nFiles nPoints nSteps

Replace the following varaibles with you own parameters:

  • model.mps: the metabolic model in .mps format.
  • warmuppoints.csv: the warmup points obtained using VFWarmup. You can also use warmup points generated using other software such as the MATLAB CobraToolbox and Cobrapy.
  • nFiles: Number of files to stores the sampled solution points.
  • nPoints: number of points per file.
  • nSteps: number of steps per point.

Example: ./ACHRCuda ecoli_core.mps ecoli_core1000warmup.csv 1 1000 1000