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| asia {bnlearn} | R Documentation |
Asia (synthetic) data set by Lauritzen and Spiegelhalter
Description
Synthetic data set on lung diseases and Asia travel from Lauritzen and Spiegelhalter (1988).
Usage
data(asia)
Format
The asia data set contains the following variables:
-
D(dyspnoea), a two-level factor with levelsyesandno. -
T(tuberculosis), a two-level factor with levelsyesandno. -
L(lung cancer), a two-level factor with levelsyesandno. -
B(bronchitis), a two-level factor with levelsyesandno. -
A(visit to Asia), a two-level factor with levelsyesandno. -
S(smoking), a two-level factor with levelsyesandno. -
X(chest X-ray), a two-level factor with levelsyesandno. -
E(tuberculosis versus lung cancer/bronchitis), a two-level factor with levelsyesandno.
Note
Lauritzen and Spiegelhalter (1988) motivate this example as follows:
“Shortness-of-breath (dyspnoea) may be due to tuberculosis, lung cancer or bronchitis, or none of them, or more than one of them. A recent visit to Asia increases the chances of tuberculosis, while smoking is known to be a risk factor for both lung cancer and bronchitis. The results of a single chest X-ray do not discriminate between lung cancer and tuberculosis, as neither does the presence or absence of dyspnoea.”
Standard learning algorithms are not able to recover the true structure of the network because of the
presence of a node (E) with conditional probabilities equal to both 0 and 1. Monte Carlo tests
seem to behave better than their parametric counterparts.
The complete BN can be downloaded from https://www.bnlearn.com/bnrepository/.
Source
Lauritzen S, Spiegelhalter D (1988). "Local Computation with Probabilities on Graphical Structures and their Application to Expert Systems (with discussion)." Journal of the Royal Statistical Society: Series B, 50(2):157–224.
Examples
# load the data.
data(asia)
# create and plot the network structure.
dag = model2network("[A][S][T|A][L|S][B|S][D|B:E][E|T:L][X|E]")
## Not run: graphviz.plot(dag)
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