find.BIB {crossdes}R Documentation

Generation of Balanced Incomplete Block Designs Using the Package AlgDesign

Description

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.

Usage

find.BIB(trt, b, k, iter = 30, check = TRUE)

Arguments

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.

Details

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.

Value

A matrix that represents the experimental design.

Note

As indicated above, the returned design is not necessarily a BIBD design.

Author(s)

Oliver Sailer sailer@statistik.uni-dortmund.de

References

Wheeler, R.E. (2004). optBlock. AlgDesign. The R project for statistical computing http://www.r-project.org/

See Also

get.plan, optBlock

Examples

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   

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