– new option “endval_steady” to pf_setup command to recompute terminal
steady state in the homotopy loop
– new options “homotopy_linearization_fallback” and
“homotopy_marginal_linearization_fallback” to pf_solver and pfwee_solver
commands, to get an approximate solution when homotopy fails to go to 100%
– new options “homotopy_initial_step_size”, “homotopy_min_step_size”,
“homotopy_step_size_increase_success_count” and “homotopy_max_completion_share”
to pf_solver and pfwee_solver commands to fine tune the homotopy behaviour
– removed option “homotopy_alt_starting_point” to pf_solver command, not really
useful
– new options “steady_solve_algo”, “steady_tolf”, “steady_tolx”,
“steady_maxit”, “steady_markowitz” to pf_solver and pfwee_solver commands, to
control the computation of the terminal steady state (and remove the
equivalent options which previously had different names in pfwee_solver command)
– Remove the terminal_steady_state_as_guess_value option to pfwee_solver
– pfwee_setup now sets the same guess values as pf_setup (i.e. terminal steady
state at all periods)
– With constant_simulation_length option, pfwee_solver uses terminal steady
state as guess values for periods that are added to the simulation
Explain that the solver is a direct sparse LU, to differentiate it from
stack_solve_algo={2,3,4} which use the same Newton algorithm but with different
solvers.
Use the new time-recursive block decomposition computed by the preprocessor
for:
- the simulation of backward models with “simul_backward”
- the perfect foresight simulation of purely backward/forward/static models
Also note that in this case, the preprocessor now defaults to “mfs=3” (i.e. it
minimizes the set of feedback variables and tries to renormalize equations).
This replaces the previous algorithm based on Dulmage-Mendelsohn (dmperm), plus
an ad hoc identification of some equations that can be evaluated (those with a
LHS equal to a variable, the log of a variable, or the diff-log of a variable).
By the way, the block_trust_region MEX has been modified so that it accepts a
boolean argument to decide whether it performs a Dulmage-Mendelsohn
decomposition (if not, then it performs a simple trust region on the whole
nonlinear system).
This provides a significant performance improvement (of almost an order of
magnitude for solve_algo=14 on a 700 equations model).
Previously, LBJ was available:
– under stack_solve_algo=6 when neither block nor bytecode were present
– under stack_solve_algo=1 with either block or bytecode (but the documentation
was not making it clear that it was LBJ)
This commit merges the two values for the option, and makes them
interchangeable. LBJ should now be invoked with stack_solve_algo=1 (but
stack_solve_algo=6 is kept for compatibility, and is a synonymous).
These options were implemented and described in the reference manual, but their
interface was missing.
By the way, make various minor improvements to the description of “model_info”
in the reference manual. In particular, remove the single quotes around the two
aforementioned options (which are a remnant from an older interface).
Also adjust the periods in Simulated_time_series (output of the perfect
foresight solver in the workspace). Note that this dseries object contains the
observations for the initial condition (M_.orig_maximum_lag observations) and
for the terminal condition (M_.orig_maximum_lead observations).
See #1838.
Fix testsuite (wrong file name)
The change implemented in 21a8a5794a broke the
testsuite and was incomplete.
– new option “overwrite” to provide the old behaviour (used to fix the testsuite);
– when concatenating several “estimated_params” block, the preprocessor now
checks that paramateres are not declared twice across blocks.
– multiple “model” and “estimated_params” block are supported
– new “model_options” statement to set model options in a global fashion
– new “model_remove” command to remove equations
– new “model_replace” block to replace equations
– new “var_remove” command to remove variables (or parameters)
– new “estimated_params_remove” block to remove estimated parameters