GPMETIS(1)

✨ GPMETIS ✨

okay bestie, gather round, because this one is literally the graph-partitioning queen 👑 and she's about to slice your graph into however many parts you want. no cap. (also she lives in the User Commands section of the manual, iykyk 💅)

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🌸 SYNOPSIS 🌸

gpmetis [options] graphfile nparts

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💖 DESCRIPTION 💖

🫶 the required parameters (you literally cannot skip these)

• graphfile — this is where your graph is at. it stores the graph that's about to get partitioned. your main character file, fr.
• nparts — the number of partitions you wanna split that graph into. that's it. that's the number.

✨ the optional parameters ✨ (the fun part, the accessories to your fit)

• -ptype=string — tells it which scheme to use for computing the k-way partitioning. possible values:
  • rb — Recursive bisectioning
  • kway — Direct k-way partitioning [default]
• -ctype=string — picks the scheme used to match the vertices of the graph during the coarsening. possible values:
  • rm — Random matching
  • shem — Sorted heavy-edge matching [default]
• -iptype=string [applies only when -ptype=rb] — picks the scheme used to compute the initial partitioning of the graph. possible values:
  • grow — Grow a bisection using a greedy scheme [default for ncon=1]
  • random — Compute a bisection at random [default for ncon>1]
• -objtype=string [applies only when -ptype=kway] — says what objective the partitioning routines will optimize. possible values:
  • cut — Minimize the edgecut [default]
  • vol — Minimize the total communication volume
• -no2hop — says the coarsening will not perform any 2-hop matchings when the standard matching fails to sufficiently contract the graph. lowkey a "no shortcuts today" flag.
• -contig [applies only when -ptype=kway] — says the partitioning routines should try to produce partitions that are contiguous. ⚠️ heads up bestie: if the input graph is not connected, this option is ignored. so it's giving "only if it can".
• -minconn [applies only when -ptype=kway] — says the partitioning routines should try to minimize the maximum degree of the subdomain graph, i.e. the graph in which each partition is a node, and edges connect subdomains with a shared interface. she's networking, literally.
• -tpwgts=filename — names the file that stores the target weights for each partition. by default, all partitions are assumed to be of the same size. (equal parts, no favoritism 🎀)
• -ufactor=int — sets the max allowed load imbalance among the partitions. a value of x means the allowed load imbalance is 1+x/1000. For ptype=rb, the load imbalance is measured as the ratio of 2*max(left,right)/(left+right), where left and right are the sizes of the respective partitions at each bisection. For ptype=kway, the load imbalance is measured as the ratio of max_i(pwgts[i])/avgpwgt, where pwgts[i] is the weight of the *i*th partition and avgpwgt is the sum of the total vertex weights divided by the number of partitions requested. For ptype=rb, the default value is 1 (i.e., load imbalance of 1.001). For ptype=kway, the default value is 30 (i.e., load imbalance of 1.03). math queen 🧮✨
• -ubvec=string — applies only for multi-constraint partitioning, and specifies the per-constraint allowed load imbalance among partitions. the required parameter corresponds to a space separated set of floating point numbers, one for each of the constraints. for example, for three constraints, the string can be "1.02 1.2 1.35" indicating a desired maximum load imbalance of 2%, 20%, and 35%, respectively. the load imbalance is defined in a way similar to ufactor. if supplied, this parameter takes priority over ufactor. 👑 she overrides.
• -niter=int — sets the number of iterations for the refinement algorithms at each stage of the uncoarsening process. default is 10.
• -ncuts=int — sets the number of different partitionings it will compute. the final partitioning is the one that achieves the best edgecut or communication volume. default is 1.
• -nooutput — says no partitioning file should be generated. stealth mode 🥷
• -seed=int — selects the seed of the random number generator.
• -dbglvl=int — selects the dbglvl.
• -help — prints this message. (hey, that's us! 🫶)

ngl, some of these flags only do anything when paired with the right -ptype. read the little brackets, bestie, they're there for a reason. 💀

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and that's the whole vibe check, fr fr. 🌈✨

this page is gpmetis version 5.1.0.3, dated July 2025. slay, go partition something. 💅🎀🦋