For stack_solve_algo={2,3} and solve_algo={7,8}, rather use a “crout” ILU decomposition for the preconditioner

In 3025a14ed9, the call to the deprecated “luinc”
has been replaced by a call to “ilu”.

However, the type of “ilu” decomposition had not been specified. The default,
“nofill”, does not make use of the “droptol” option which was used with
“luinc”. Also, under Octave, it does not work when there is a zero on the
diagonal of the input matrix.

Rather use the “crout” type, which addresses these two issues.

matlab/solve_one_boundary.m

@@ -73,6 +73,7 @@ function [y, T, oo_, info] = solve_one_boundary(fname, y, x, params, steady_stat
 
 Blck_size=size(y_index_eq,2);
 correcting_factor=0.01;
+ilu_setup.type='crout';
 ilu_setup.droptol=1e-10;
 max_resa=1e100;
 reduced = 0;