Description Objects from the Class Slots Extends Methods Author(s) References See Also Examples
This class contains all the data needed for characterizing the mutagenetic
trees mixture model (mixture parameters, mixture components, ...).
The tree components of the model are given as a list of directed graphNEL
objects.
Objects can be created by calls of the form new("RtreemixModel",
ParentData, Weights, WeightsCI, Resp, CompleteMat, Star, Trees)
.
The RtreemixModel
class extends the RtreemixData
class
and specifies the mutagenetic trees mixture model. If the model is not
randomly generated the parent class gives the RtreemixData
used for learning the mixture model. The directed trees that build up
the model are represented as a list of directed graphNEL
objects, and their weights (the mixture parameters) are given as a
numeric vector. This class can also contain other useful information
connected with the mixture model like confidence intervals for the
mixture parameters and the edge weights (resulting from a bootstrap
analysis), an indicator for the presence of the star component, etc.
They are all listed in the text below with brief descriptions.
The ParentData
is an RtreemixData
object that specifies the
data used for estimating the mutagenetic trees mixture model. It is
not specified for random mixture models, since they are not estimated
from a given dataset but generated randomly.
The Weights
is a numeric vector
that contains the mixture
parameters of the model. Its length equals the length of the
list
of tree components Trees
.
The WeightsCI
is a named list
with length equal to the
length of the Weights
. Each list element is a numeric
vector
of length two specifying the lower and upper bound of
the confidence interval for the corresponding mixture parametar. The
confidence intervals are derived using the bootstrap method.
The Resp
is a numeric matrix
that specifies the responsibility
of each tree component to generate each of the patterns in the
ParentData
. The number of rows in Resp
is equal
to the number of trees in the mixture (the length of the list
Trees
) and the number of columns equals the number of patients
in ParentData
. For random mixture models it is an empty matrix,
since they are not estimated from a given dataset.
The CompleteMat
is a binary matrix
that specifies the complete
data in case some measurements for some patients are missing in
the data used for learning the model (the ParentData
). It has
the same size as the matrix specifying the data in ParentData
.
The missing data are estimated in the EM-algorithm used for fitting
the mixture model. When there are no missing data in
ParentData
, or the model is randomly generated the CompleteMat
is an
empty matrix.
The Star
is an indicator of the presence of a noise (star) component
and is mostly relevant for models with a single tree component, since it is assumed that
mixture models with at least two components always have the noise
as a first component. It is of type logical
.
The Trees
is a list
of directed graphNEL
objects, each for every tree component in the mixture model. The
genetic events are represented as nodes in the graphs. The
edgeData
of each tree can have two attributes: "weight"
and "ci"
. Please see the help page on graph-class
and
graphNEL-class
in the package graph
. The "weight"
attribute is for edge weight,
i.e. the conditional probability that the child event of the edge occured given
that the parent event already occured. The "ci"
attribute is
for the bootstrap confidence intervals for the edge weight (a numeric vector
with length two).
Weights
:Object of class "numeric"
. The length
of the Weights
must be equal to the length of Trees
.
WeightsCI
:Object of class "list"
. The length
of the WeightsCI
must be equal to the length of Weights
.
Resp
:Object of class "matrix"
. The number of
rows of Resp
must be identical to the length of
Trees
, and its number of columns to the number of patients
in the dataset used for estimating the mixture model (ParentData
).
CompleteMat
:Object of class "matrix"
. When
specified (when there are missing data) the size of the
CompleteMat
must be equal to the size of the matrix used to
estimate the model.
Star
:Object of class "logical"
.
Trees
:Object of class "list"
. The length of
Trees
equals the length of Weights
.
Class "RtreemixData"
, directly.
signature(object = "RtreemixModel")
: A
method used for obtaining the complete dataset, in case there were
any missing measurements for some patients in the dataset used to
learn the mixture model.
signature(object = "RtreemixModel")
: A method for
obtaining the matrix of responsibilities for the trees to generate
each of the samples in the dataset used for learning the model (ParentData
).
signature(object = "RtreemixModel")
: A method for
checking the presence of a noise component in the mixture model
(informative only for models with one tree component).
signature(object = "RtreemixModel")
: A method
for obtaining the tree components of the mixture model as a list
of directed graphNEL
objects.
signature(object = "RtreemixModel")
: A method
for obtaining the mixture parameters (the weights of the trees in
the model).
signature(object = "RtreemixModel")
: A
method for replacing the value of the slot Weights
with a
specified numeric
vector. The components of this vector
have to sum up to one.
signature(object = "RtreemixModel")
: A method
for obtaining the weights of the mixture parameters.
signature(object = "RtreemixModel")
: A method
for obtaining the ParentData
of the mixture model, i.e. the
data used for learning the model.
signature(object = "RtreemixModel", k =
"numeric")
: A method for obtaining the k-th tree component of the
mixture model as a directed graphNEL
object.
signature(object = "RtreemixModel")
: A method
for obtaining the number of tree components building up the mixture model.
signature(x = "RtreemixModel", y = "missing")
: A method
for visualizing the tree components comprising a mutagenetic trees mixture
model. The user can also specify the fontSize
(the default value is 8)
used for the text labels of the nodes and the edges of the plotted trees.
Additionally, one can use the parameter k
to plot a certain tree
component from the mixture model.
Jasmina Bogojeska
Learning multiple evolutionary pathways from cross-sectional data, N. Beerenwinkel et al.
RtreemixGPS-class
, RtreemixStats-class
,
RtreemixData-class
, RtreemixSim-class
,
fit-methods
, bootstrap-methods
,
generate-methods
, comp.models
, comp.trees
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | ## Generate a random RtreemixModel object with 2 components.
rand.mod <- generate(K = 2, no.events = 9, noise.tree = TRUE, prob = c(0.2, 0.8))
show(rand.mod)
plot(rand.mod) ## plot the tree components of the model
plot(rand.mod, k = 2) ## plot the second component of the model
## Draw data from a specified mixture model.
draws <- sim(model = rand.mod, no.draws = 200)
show(draws)
## Create an RtreemixModel object by fitting model to the drawn data.
mod <- fit(data = draws, K = 2, equal.edgeweights = TRUE, noise = TRUE)
show(mod)
## See the values of the slots of the RtreemixModel object.
Weights(mod)
Resp(mod)
CompleteMat(mod)
Star(mod)
Trees(mod)
## See data used for learning the model.
getData(mod)
## See the number of tree components in the mixture model.
numTrees(mod)
## See a specific tree component k.
getTree(object = mod, k = 2)
## See the conditional probabilities assigned to edges of the second tree component.
edgeData(getTree(object = mod, k = 2), attr = "weight")
## See the probability distribution encoded by the model on the set of all possible patterns.
distr <- distribution(model = mod)
distr
## Get the probabilities.
distr$probability
## See the probability distribution encoded by the model on the set of all possible patterns
## calculated for given sampling mode, and input and output parameters.
distr1 <- distribution(model = mod, sampling.mode = "exponential", sampling.param = 1, output.param = 1)
distr1
## Create a RtreemixModel and analyze its variance with the bootstrap method.
mod.boot <- bootstrap(data = draws, K = 2, equal.edgeweights = TRUE, B = 100)
## See the confidence intervals for the mixture parameters (the weights).
WeightsCI(mod.boot)
## See the confidence intervals of the conditional probabilities assigned to the edges.
edgeData(getTree(mod.boot, 2), attr = "ci")
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