Add documentation for linear_solver module

doc/userdoc.org

@@ -4037,6 +4037,73 @@ The following operators are defined
   \end{equation*}
 #+end_src
 
+*** The ~linear_solver~ module
+
+This module provides the following functions
+#+NAME: get-module-info-linear-solver
+#+BEGIN_SRC pugs :exports both :results output
+  cout << getModuleInfo("linear_solver") << "\n";
+#+END_SRC
+#+RESULTS: get-module-info-linear-solver
+
+**** ~linear_solver~ provided functions
+
+The set of provided functions is used to define the global behavior of
+~pugs~ linear system solver.
+
+***** Utility functions
+
+An important function is
+
+****** ~getLSAvailable: void -> string~
+
+This shows the available options or libraries that are available. It
+depends on the compilation options of the code.
+
+#+NAME: get-ls-available-example
+#+BEGIN_SRC pugs :exports both :results output
+  import linear_solver;
+  cout << getLSAvailable() << "\n";
+#+END_SRC
+#+results: get-ls-available-example
+
+
+****** ~getLSOptions: void -> string~
+
+This function show the current tuning of the global linear solver
+#+NAME: get-ls-options-example
+#+BEGIN_SRC pugs :exports both :results output
+  import linear_solver;
+  cout << getLSOptions() << "\n";
+#+END_SRC
+#+results: get-ls-options-example
+
+***** Tuning functions
+
+****** ~setLSEpsilon: R -> void~
+
+Sets the relative epsilon criterion for iterative methods.
+
+****** ~setLSLibrary: string -> void~
+
+Selects the library to use.
+
+****** ~setLSMaxIter: N -> void~
+
+Sets the maximum number of iterations.
+
+****** ~setLSMethod: string -> void~
+
+Sets the method to solve linear systems.
+
+****** ~setLSPrecond: string -> void~
+
+Sets the preconditioner type.
+
+****** ~setLSVerbosity: B -> void~
+
+Sets verbosity mode to ~true~ or ~false~ for linear solvers.
+
 [fn:pugs-def] ~pugs~: Parallel Unstructured Grid Solvers
 [fn:MPI-def] ~MPI~: Message Passing Interface
 [fn:DSL-def] ~DSL~: Domain Specific Language~