RussianTiger {pomdp} | R Documentation |
Russian Tiger Problem POMDP Specification
Description
This is a variation of the Tiger Problem introduces in Cassandra et al (1994) with an absorbing state after a door is opened.
Format
An object of class POMDP.
Details
The original Tiger problem is available as Tiger. The original problem is
an infinite-horizon problem, where when the agent opens a door then the
problem starts over. The infinite-horizon problem can be solved if
a discount factor \gamma < 1
is used.
The Russian Tiger problem uses no discounting, but instead
adds an absorbing state done
which is reached
after the agent opens a door. It adds the action nothing
to indicate
that the agent does nothing. The nothing
action is only available in the
state done
indicated by a reward of -Inf
from all after states. A new
observation done
is only emitted by the state done
. Also, the Russian
tiger inflicts more pain with a negative reward of -1000.
See Also
Other POMDP_examples:
POMDP()
,
POMDP_example_files
,
Tiger
Examples
data("RussianTiger")
RussianTiger
# states, actions, and observations
RussianTiger$states
RussianTiger$actions
RussianTiger$observations
# reward (-Inf indicates unavailable actions)
RussianTiger$reward
sapply(RussianTiger$states, FUN = function(s) actions(RussianTiger, s))
plot_transition_graph(RussianTiger, vertex.size = 30, edge.arrow.size = .3, margin = .5)
# absorbing states
absorbing_states(RussianTiger)
# solve the problem.
sol <- solve_POMDP(RussianTiger)
policy(sol)
plot_policy_graph(sol)