Title LAMA/FF synergy does not return h=0 for goals even without r-orders
Priority bug Status resolved
Superseder Nosy List erez, gabi, malte, salome, silvia
Assigned To salome Keywords
Optional summary

Created on 2011-03-30.09:36:35 by silvia, last changed by gabi.

msg2534 (view) Author: gabi Date: 2013-07-01.12:06:12
I added a comment to issue207 (revise search code) that the output for lazy
search should be clearer. Since LAMA/FF synergy behaves correct in this respect,
I close this issue.
msg2524 (view) Author: gabi Date: 2013-06-27.11:17:13
Just to make this clear: This is really only an output problem, the heuristic
estimate of the goal state is 0.
msg2523 (view) Author: gabi Date: 2013-06-27.11:08:27
This does not really look like a bug. The behaviour is triggered by the
following code lines in the lazy search:

            if (check_goal_and_set_plan(current_state))
                return SOLVED;
            if (search_progress.check_h_progress(current_g)) {

The output of the "Best heuristic value" is a side effect of
search_progress.check_h_progress, which is not called for goal nodes. Should we
change this? I am not sure whether it is worth to make the code more complicated
for this, especially since we are also planning a major revision of the search
implementation anyway.
msg2508 (view) Author: gabi Date: 2013-06-25.14:56:52
It would be interesting to see whether the problem still exists with the recent
changes to the landmark code. Salomé, could you please try this?
msg1290 (view) Author: silvia Date: 2011-03-30.09:36:35
When running the task from Issue127 with the LAMA/FF synergy, the best heuristic
value does not drop down to 0 before finding a goal state, even when we are not
using reasonable orderings. Use e.g. the following call:

 ./downward --heuristic
--search "lazy_greedy(hlm, hff, preferred=(hlm, hff))" < output
Date User Action Args
2013-07-01 12:06:56gabisetstatus: chatting -> resolved
2013-07-01 12:06:12gabisetmessages: + msg2534
2013-06-27 11:17:13gabisetmessages: + msg2524
2013-06-27 11:08:27gabisetmessages: + msg2523
2013-06-25 14:56:52gabisetassignedto: salome
messages: + msg2508
nosy: + gabi, salome
2011-03-30 09:36:35silviacreate