libitsol1 binary package in Ubuntu Bionic i386

 ITSOL is a library of iterative solvers for general sparse linear
 systems of equations. ITSOL can be viewed as an extension of the itsol
 module in SPARSKIT. It is written in C and offers a selection of
 recently developed preconditioners. The preconditioner suite includes:
 .
   * ILUK (ILU preconditioner with level of fill)
   * ILUT (ILU preconditioner with threshold)
   * ILUC (Crout version of ILUT)
   * VBILUK (variable block preconditioner with level of fill - with
     automatic block detection)
   * VBILUT (variable block preconditioner with threshold - with
     automatic block detection)
   * ARMS (Algebraic Recursive Multilevel Solvers -- includes actually
     several methods - In particular the standard ARMS and the ddPQ
     version which uses nonsymmetric permutations)
 .
 Note that ITSOL is a scalar package. You may find parallel implementations
 of some of the preconditioners listed above in pARMS.

Source package