- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation (water depth + temperature, water depth up to
machine accuracy)
- solver and accuracy for propagation set to default (GMRES + 1.E-8)
- accuracy for diffusion of tracers can be set to 1.E-15 without significant
increase of CPU time
- preconditioning for diffusion = 34 = 2*17 for tracers + velocities for
more efficiency (less iterations)
- solver and preconditioning for PPE = conjugate gradient (1) and 34
- non-hydrostatic version (new default since 8.0)

- default options to solve propagation (Krylov space dimensions, accuracy)
without significant increase of CPU time
- no diffusion along x and y with keyword
COEFFICIENT FOR HORIZONTAL DIFFUSION OF VELOCITIES = 0. rather than
SCHEME FOR DIFFUSION OF VELOCITIES = 0

This allows CPUs to operate at a higher clock rate, to speed up CPU-bound calculations

- SOLVER FOR PROPAGATION = 7 (GMRES = default) as quite more efficient than
old choice 2 (conjugate residual) or 1 (conjugate gradient)
This choice enables to set ACCURACY FOR PROPAGATION to its default value 1.E-8
rather than 1.E-6 with quite the same CPU times

- TIDAL FLATS = YES (default value) to improve mass conservation (water depth
+ tracer, water depth up to machine accuracy)
- SOLVER FOR PROPAGATION = 7 (GMRES = default) as the most efficient
- with theses choices of solvers, accuracies for propagation and PPE can be set
to default = 1.E-8
- ==> less differences between sequential and parallel runs

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation (water depth + temperature, water depth up to
machine accuracy)
- SCHEME FOR ADVECTION OF VELOCITIES = 5 (PSI) rather than 1 (characteristics)
for better mass conservation + reduced differences between seq/par runs
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example
- accuracies for diffusion of velocities/tracers/k-epsilon + PPE set to
1.E-15 as easily and efficiently reached with this set-up

- TIDAL FLATS = YES (default value) to improve mass conservation (water depth
+ tracer, water depth up to machine accuracy)
- use preconditioning 34 for the diffusion of velocities (a little bit more
efficient)

- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES or CGSTAB (previous choice) for this example

- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example
- switch from characteristics to defaul advection scheme for velocities (LIPS)
to decrease differences between sequential and parallel runs
- use preconditioning 34 for the diffusion of velocities (a little bit more
efficient)
- default accuracies for propagation and PPE with this setting of solvers
(1.E-8)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example
- accuracy for propagation decreased to 1.E-15 (improved differences between
sequential and parallel runs)
- switch to non-hydrostatic version

Vertical velocity W along z, rather than horizontal velocity V along x

- SOLVER FOR DIFFUSION OF VELOCITIES = 1 (conjugate gradient)
+ PRECONDITIONING FOR DIFFUSION OF VELOCITIES = 34 (= 2*17) rather than GMRES
- accuracy for propagation and diffusion of velocities = 1.E-15 easily reached
with previous choices
- ACCURACY FOR PPE set to 1.E-9

- SOLVER FOR PROPAGATION = 7 (GMRES) + SOLVER FOR PPE = 1 (conjugate gradient)
+ PRECONDITIONING FOR PPE = 34 (=2*17) rather than conjugate residual (= 2) for
propagation and GMRES for PPE
- accuracies for propagation and PPE set to default values (1.E-8)

 - TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example
- use of preconditioning 34 for diffusion of every variable (more efficient)
- accuracy for PPE and propagation decreased from 10^-10 to 10^-12

(including non-hydrostatic version: no differences except for W, light for W)
IMPLICITATION FOR VELOCITIES has no impact

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
in particular for prismatic elements (also chosen for tetrahedra)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example (very few iterations are needed)
- ACCURACY FOR PROPAGATION = 1.E-15 as easily solved (only 2 iterations needed)
- ACCURACY FOR PPE = 1.E-9 (less than 10 iterations needed)
- PRECONDITIONING FOR DIFFUSION OF K-EPSILON = 34 to improve efficiency
(turbulent variable)
- PRECONDITIONING FOR DIFFUSION OF VELOCITIES set to default
(not understood why 0 previously, no clear differences)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, more
efficient than GMRES for this example (very few iterations are needed)
- ACCURACY FOR DIFFUSION OF VELOCITIES = 1.E-15 as easily solved
+ PRECONDITIONING FOR DIFFUSION OF VELOCITIES = 34 to improve efficiency

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation of water + tracer
- use of gradient conjugate + preconditioning 34 = 2*17 to solve PPE, quite
more efficient than GMRES for this example
- switch to non-hydrostatic version (default) but no significant differences

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation of water
- use of gradient conjugate to solve PPE (a little bit more efficient)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation of water (already chosen for NH example)
- use of default advection scheme for velocities (LIPS): better parallelisation
than with method of characteristics
- use of gradient conjugate to solve PPE (little bit more efficient)

Add comparison of the advection of tracers with PC1/PC2/LIPS

Same time step for non-hydrostatic and hydrostatic versions (now = 0.4 s as NH
before)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0)
to improve mass conservation of water+tracer
- preconditionings = 34 when possible (diffusion of velocities/tracers + PPE
as using conjugate gradients) for great efficiency to converge to the chosen
accuracy (down to 1.E-15 for the diffusion of tracers as easily reached for
this example)

- TIDAL FLATS = YES (default value) to improve mass conservation of water
- SOLVER FOR PPE = 1: conjugate gradient is a little bit more efficient than
CGSTAB (= 6) or GMRES (= 7) for this example

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
for both examples gouttedo + thompson
- FREE SURFACE GRADIENT COMPATIBILITY : 0.8 for thompson example to decrease
spurious oscillations: 0.9 is not enough, 0.8 is OK, 0. is not so needed

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- FREE SURFACE GRADIENT COMPATIBILITY = 0.9 to decrease spurious oscillations
- SOLVER FOR PROPAGATION = 7 (better accuracy with quite same CPU time
rather than 2)
- switch to non-hydrostatic version (default)

- non-hydrostatic version (strange vertical velocity component W with
hydrostatic hypothesis)
- delete useless keywords with a direct solver (= 8)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- switch to non-hydrostatic version (default)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0) and
TIDAL FLATS = YES (default value) to improve mass conservation of water
- SOLVER FOR PPE = 1 (conjugate gradient) + PRECONDITIONING FOR PPE = 34
(= 2*17) which combo can be used with finer accuracy with similar CPU time
as default SOLVER FOR PPE = 7 (GMRES)

- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0),
- IMPLICITATION OF VELOCITIES, ACCURACY FOR PPE, TIDAL FLATS set to their
default value,
- SCHEME FOR DIFFUSION OF VELOCITIES = 1 (with diffusion coefficients = 0)
rather than 0 to have no diffusion.
CPU time is a little bit shorter.
Mass conservation is improved (to machine precision, rather than 5 times
more of magnitude).

by using TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0
rather than 1)

- decrease SOLVER ACCURACY from 1.E-4 to 1.E-6
- TREATMENT OF NEGATIVE DEPTHS = 2 (new default value since release 9.0, rather
than 1)

for drogues files

punctual sources+control sections (T2D+T3D), sources by regions+fluxlines (T2D)