MatrixMarket is a format for the storage of dense or sparse numeric matrix data.

This open format was created and is used by the National Institute of Standards and Technology (NIST).

The commands Import, Export, ImportMatrix, and ExportMatrix can read and write to the MatrixMarket format.

$H≔\mathrm{Import}\left(''example/hilbert100.mtx''\,\mathrm{base}=\mathrm{datadir}\right)$

$H≔\begin{array}{c}\left[\begin{array}{ccccccccccc}1.& 0.500000000000000& 0.333333333300000& 0.250000000000000& 0.200000000000000& 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& \dots \\ 0.500000000000000& 0.333333333300000& 0.250000000000000& 0.200000000000000& 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& \dots \\ 0.333333333300000& 0.250000000000000& 0.200000000000000& 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& \dots \\ 0.250000000000000& 0.200000000000000& 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& \dots \\ 0.200000000000000& 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& \dots \\ 0.166666666700000& 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& 0.0666666666700000& \dots \\ 0.142857142900000& 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& 0.0666666666700000& 0.0625000000000000& \dots \\ 0.125000000000000& 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& 0.0666666666700000& 0.0625000000000000& 0.0588235294100000& \dots \\ 0.111111111100000& 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& 0.0666666666700000& 0.0625000000000000& 0.0588235294100000& 0.0555555555600000& \dots \\ 0.100000000000000& 0.0909090909100000& 0.0833333333300000& 0.0769230769200000& 0.0714285714300000& 0.0666666666700000& 0.0625000000000000& 0.0588235294100000& 0.0555555555600000& 0.0526315789500000& \dots \\ ⋮& ⋮& ⋮& ⋮& ⋮& ⋮& ⋮& ⋮& ⋮& ⋮& \end{array}\right]\\ \hfill \text{100 × 100 Matrix}\end{array}$

$M≔\mathrm{LinearAlgebra}:-\mathrm{RandomMatrix}\left(100\,\mathrm{datatype}=\mathrm{float}\left[8\right]\right)\:$

$\mathrm{Export}\left(''example.mtx''\,M\,\mathrm{base}=\mathrm{homedir}\right)$

$234927$