Description Usage Arguments Details Value Author(s) References See Also Examples
Generates correrlated binary cluster data given value of Intracluster Correlation, proportion of event and it's variance, number of clusters, cluster size and it's variance, and minimum cluster size
1 2 | rcbin1(prop = 0.5, prvar = 0, noc, csize, csvar = 0, mincsize = 2,
rho)
|
prop |
A numeric value between 0 and 1 denoting assumed proportion of event in interest, default value is 0.5. See Detail |
prvar |
A numeric value between 0 and 1 denoting varince in assumed proportion of event ( |
noc |
A positive numeric value telling the number of clusters to be generated |
csize |
A numeric value (≥ 2) denoting cluster size desired |
csvar |
A positive numeric value denoting Variance of cluster size, default value is 0, see Detail |
mincsize |
A numeric value (≥ 2) denoting the minimum cluster size desired, default value is 2, see Detail |
rho |
A numeric value between 0 and 1 denoting desired level of Intracluster Correlation |
If supplied value of prvar
is 0, the event proportion for all clusters is considered constant as supplied by prop
.
If supplied prvar
is > 0, cluster specific event proportions are generated from Beta distribution with
shape1
and shape2
parameters a and b respectively, see rbeta
The shape parameters are obtained using supplied values of prop
and prvar
by solving the equations
prop
= a/(a + b) and prvar
= ab/[(a + b)^2(1 + a + b)]
If supplied value of csvar
is 0, cluster of equal size (csize
) will be generated. For csvar
> 0, will be generated from
Normal or Negative Binomial dsitributions depending on relationship between csize
and csvar
.
If csvar
< csize
, the varying cluster sizes will be generated
from a Normal distribution with mean = csize
and variacne = csvar
(see rnorm
).
If csvar
≥ csize
i.e. in the case of overdispersion,
cluster sizes will be generated from Negative Bionomial distribution using mu
= csize
and
size
= csize
/(csize
*(cscv
^2 - 1))
(see rnbinom
), where cscv
is the coefficient of variation of cluster sizes defined as
sqrt(csvar)
/csize
. If the size of any cluster
is generated as less than 2, it will be replaced by the supplied value of minimum cluster size (mincsize
) which has a default value
of 2
A dataframe with two columns presenting cluster id (cid
) and a binary response (y
) variables
Akhtar Hossain mhossain@email.sc.edu
Lunn, A.D. and Davies, S.J., 1998. A note on generating correlated binary variables. Biometrika, 85(2), pp.487-490.
1 | rcbin1(prop = .6, prvar = .1, noc = 100, csize = 10, csvar = 12, rho = 0.2, mincsize = 2)
|
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