find.BIB {crossdes} | R Documentation |
The function optBlock
of the library AlgDesign
is used to search for balanced incomplete block designs
(BIBDs). The design is assigned to a matrix where rows represent blocks (subjects) and
columns represent periods.
find.BIB(trt, b, k, iter = 30, check = TRUE)
trt |
An integer > 1 giving the number of treatments of the design. |
b |
An integer > 1 giving the number of rows (subjects) of the design. |
k |
An integer > 1 giving the number of columns (periods) of the design. |
iter |
The number of iterations of the function optBlock |
check |
Logical flag. Set to FALSE only if no checks for BIBD are desired. |
The function optBlock
tries to find a D-optimal block design for the specified parameters.
The resulting design need not be a BIBD.
The necessary conditions for the existence are that bk/trt and
bk(k-1)/(trt(trt-1)) positive intergers.
They are NOT checked automatically.
Even if they are fulfilled, there need not be a BIBD.
If no BIBD is found, the function is iterated.
If no BIBD is found after iter
iterations, the search is terminated.
The resulting design may be checked by the function isGYD
and the result
displayed on the screen. The resulting design matrix is returned.
A matrix that represents the experimental design.
As indicated above, the returned design is not necessarily a BIBD design.
Oliver Sailer sailer@statistik.uni-dortmund.de
Wheeler, R.E. (2004). optBlock. AlgDesign. The R project for statistical computing http://www.r-project.org/
find.BIB(10,30,4) # BIBD find.BIB(3,3,3) # BIBD find.BIB(5,5,3, 100) # There is no BIBD for these parameters