---
name: "mm2gv"
section: "1"
platform: "linux"
package: "graphviz"
version: "16.1.0-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/mm2gv"
---

# mm2gv(1)

Matrix Market-DOT converters

delim $$

## NAME

mm2gv - Matrix Market-DOT converters

## SYNOPSIS

**mm2gv** \[ **-cluv?** \] \[ **-U***i* \] \[ **-o***outfile* \] \[  *file* \]\

## DESCRIPTION

**mm2gv** converts a sparse matrix of the Matrix Market format to a graph in the GV (formerly DOT) format.  If the matrix *M* is not square, the graph is considered bipartite and the matrix is viewed as a bipartite graph adjacency matrix, with the rows and columns of the matrix specifying the two sets of vertices. Equivalently, the matrix is converted into a symmetric square matrix

| | |
| --- | --- |
| 0 | *M* |
| $*M* sup *T*$ | 0 |

a block matrix with square blocks of 0's in the upper left and lower right, the upper right block being *M* and the lower left block being the transpose of *M*. This matrix is then viewed as the adjacency matrix of the graph.

For a square matrix, **mm2gv** uses it directly as an adjacency matrix if its pattern of non-zero entries is symmetric; otherwise, it will treat it as a bipartite graph as with the case of non-square matrices. This behavior can be modified by the **-U** flag.

## OPTIONS

The following options are supported:

- **-c**

  This flag causes **mm2gv** to assign colors to the edges. The matrix element is scaled to the range \[0,1\] depending on where it lies between the minimum and maximum set matrix values. This scaled value is used as the *"wt"* attribute of the corresponding edge.  In addition, this scalar value is mapped to an RGB value, which is stored as the edge *"color"*.

- **-l**

  If set, **mm2gv** attaches a label to the graph indicating the base name of the input file, and the number of nodes and edges.

- **-u**

  If specified, the graph is assumed to be undirected. By default, the graph generated is directed.

- **-v**

  This flag causes **mm2gv** to store the matrix values as the *"len"* attribute of the corresponding edge.

- **-U***bflag*

  Specifies how square matrices are handled. If *bflag* is 0, a square matrix will always be treated as an adjacency matrix.   If *bflag* is 1 (the default), a square matrix with a symmetric pattern of non-zero entries will be used as an adjacency matrix; otherwise, it will be used a bipartite graph. If *bflag* is 2, a symmetric matrix will be used as an adjacency matrix; otherwise, it will be used a bipartite graph. If *bflag* is 3, any input matrix will be treated like a bipartite graph.

- **-o***outfile*

  Prints output to the file *outfile*. If not given, **mm2gv** uses stdout.

- The following operand is supported:

  ## OPERANDS

- *file*

  Name of the file in MatrixMarket format. If no *file* operand is specified, the standard input will be used.

## RETURN CODES

Return **0** if there were no problems during conversion; and non-zero if any error occurred.

## AUTHORS

Yifan Hu \<yifanhu@yahoo.com\>\
 Emden R. Gansner \<erg@graphviz.com\>

## ADDITIONAL INFO

See http://math.nist.gov/MatrixMarket/ for description of the format and http://www.cise.ufl.edu/research/sparse/matrices/ for a large collection of sparse matrices in this format.