make.bisse {diversitree} | R Documentation |
Binary State Speciation and Extinction Model
Description
Prepare to run BiSSE (Binary State Speciation and Extinction) on a phylogenetic tree and character distribution. This function creates a likelihood function that can be used in maximum likelihood or Bayesian inference.
Usage
make.bisse(tree, states, unresolved=NULL, sampling.f=NULL, nt.extra=10,
strict=TRUE, control=list())
starting.point.bisse(tree, q.div=5, yule=FALSE)
Arguments
tree |
An ultrametric bifurcating phylogenetic tree, in
|
states |
A vector of character states, each of which must be 0 or
1, or |
unresolved |
Unresolved clade information: see section below for structure. |
sampling.f |
Vector of length 2 with the estimated proportion of
extant species in state 0 and 1 that are included in the phylogeny.
A value of |
nt.extra |
The number of species modelled in unresolved clades (this is in addition to the largest observed clade). |
control |
List of control parameters for the ODE solver. See details below. |
strict |
The |
q.div |
Ratio of diversification rate to character change rate. Eventually this will be changed to allow for Mk2 to be used for estimating q parameters. |
yule |
Logical: should starting parameters be Yule estimates rather than birth-death estimates? |
Details
make.bisse
returns a function of class bisse
. This
function has argument list (and default values)
f(pars, condition.surv=TRUE, root=ROOT.OBS, root.p=NULL, intermediates=FALSE)
The arguments are interpreted as
-
pars
A vector of six parameters, in the orderlambda0
,lambda1
,mu0
,mu1
,q01
,q10
. -
condition.surv
(logical): should the likelihood calculation condition on survival of two lineages and the speciation event subtending them? This is done by default, following Nee et al. 1994. -
root
: Behaviour at the root (see Maddison et al. 2007, FitzJohn et al. 2009). The possible options are-
ROOT.FLAT
: A flat prior, weightingand
equally.
-
ROOT.EQUI
: Use the equilibrium distribution of the model, as described in Maddison et al. (2007). -
ROOT.OBS
: Weightand
by their relative probability of observing the data, following FitzJohn et al. 2009:
-
ROOT.GIVEN
: Root will be in state 0 with probabilityroot.p[1]
, and in state 1 with probabilityroot.p[2]
. -
ROOT.BOTH
: Don't do anything at the root, and return both values. (Note that this will not give you a likelihood!).
-
-
root.p
: Root weightings for use whenroot=ROOT.GIVEN
.sum(root.p)
should equal 1. -
intermediates
: Add intermediates to the returned value as attributes:-
cache
: Cached tree traversal information. -
intermediates
: Mostly branch end information. -
vals
: Rootvalues.
At this point, you will have to poke about in the source for more information on these.
-
starting.point.bisse
produces a heuristic starting point to
start from, based on the character-independent birth-death model. You
can probably do better than this; see the vignette, for example.
bisse.starting.point
is the same code, but deprecated in favour
of starting.point.bisse
- it will be removed in a future
version.
Unresolved clade information
Since 0.10.10 this is no longer supported. See the package README for more information.
This must be a data.frame
with at least the four columns
-
tip.label
, giving the name of the tip to which the data applies -
Nc
, giving the number of species in the clade -
n0
,n1
, giving the number of species known to be in state 0 and 1, respectively.
These columns may be in any order, and additional columns will be ignored. (Note that column names are case sensitive).
An alternative way of specifying unresolved clade information is to
use the function make.clade.tree
to construct a tree
where tips that represent clades contain information about which
species are contained within the clades. With a clade.tree
,
the unresolved
object will be automatically constructed from
the state information in states
. (In this case, states
must contain state information for the species contained within the
unresolved clades.)
ODE solver control
The differential equations that define the
BiSSE model are solved numerically using ODE solvers from the GSL
library or deSolve's LSODA. The control
argument to
make.bisse
controls the behaviour of the integrator. This is a
list that may contain elements:
tol
: Numerical tolerance used for the calculations. The default value of1e-8
should be a reasonable trade-off between speed and accuracy. Do not expect too much more than this from the abilities of most machines!eps
: A value that when the sum of the D values drops below, the integration results will be discarded and the integration will be attempted again (the second-chance integration will divide a branch in two and try again, recursively until the desired accuracy is reached). The default value of0
will only discard integration results when the parameters go negative. However, for some problems more restrictive values (on the order ofcontrol$tol
) will give better stability.backend
: Select the solver. The three options here aregslode
: (the default). Use the GSL solvers, by default a Runge Kutta Kash Carp stepper.deSolve
: Use the LSODA solver from thedeSolve
package. This is quite a bit slower at the moment.
deSolve
is the only supported backend on Windows.
Author(s)
Richard G. FitzJohn
References
FitzJohn R.G., Maddison W.P., and Otto S.P. 2009. Estimating trait-dependent speciation and extinction rates from incompletely resolved phylogenies. Syst. Biol. 58:595-611.
Maddison W.P., Midford P.E., and Otto S.P. 2007. Estimating a binary character's effect on speciation and extinction. Syst. Biol. 56:701-710.
Nee S., May R.M., and Harvey P.H. 1994. The reconstructed evolutionary process. Philos. Trans. R. Soc. Lond. B Biol. Sci. 344:305-311.
See Also
constrain
for making submodels, find.mle
for ML parameter estimation, mcmc
for MCMC integration,
and make.bd
for state-independent birth-death models.
The help pages for find.mle
has further examples of ML
searches on full and constrained BiSSE models.
Examples
## Due to a change in sample() behaviour in newer R it is necessary to
## use an older algorithm to replicate the previous examples
if (getRversion() >= "3.6.0") {
RNGkind(sample.kind = "Rounding")
}
pars <- c(0.1, 0.2, 0.03, 0.03, 0.01, 0.01)
set.seed(4)
phy <- tree.bisse(pars, max.t=30, x0=0)
## Here is the 52 species tree with the true character history coded.
## Red is state '1', which has twice the speciation rate of black (state
## '0').
h <- history.from.sim.discrete(phy, 0:1)
plot(h, phy)
lik <- make.bisse(phy, phy$tip.state)
lik(pars) # -159.71