For example, I have
h = SparseArray@{{0, I}, {-I, 0}}
If I export h as matrix market format(.mtx) like
ExportString[ h, "MTX"]
I got
%%MatrixMarket matrix coordinate complex skew-symmetric
%Created with the Wolfram Language : www.wolfram.com
2 2 1
2 1 0.0000000000000000E+00 -1.0000000000000000E+00
It automatically recognize the symmetry property of h, that is fantastic!! However, I don't want this. I want a general coordinate format, like this
%%MatrixMarket matrix coordinate complex general
%Created with the Wolfram Language : www.wolfram.com
2 2 2
1 2 0.0000000000000000E+00 1.0000000000000000E+00
2 1 0.0000000000000000E+00 -1.0000000000000000E+00
On the page of mtx doc, there is very limited documentation, though it says
Export["file.mtx",expr,elem] creates a Matrix Market file by treating expr as specifying element elem.
I don't know what does it mean by "specifying element elem". And it also says
Export["file.mtx",expr,Subscript[opt, 1]->Subscript[val, 1],[Ellipsis]] exports expr with the specified option elements taken to have the specified values.
What kind of option is supported?
One the page of matrix market format, it says
Several instances of each of these basic formats are defined. These are obtained by specifying an arithmetic field for the matrix entries (i.e., real, complex, integer, pattern) and a symmetry structure which may reduce the size of the data file (i.e. general, symmetric, skew-symmetric, Hermitian) by storing nonzero entries only on or below the main diagonal.
So is it possible control symmetry property when exporting matrix as Matrix Market format .mtx in Mathematica? Or more specifically, just force .mtx output general coordinate format without any symmetry?