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)
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 |
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 \frac{bk}{trt}
and
\frac{bk(k-1)}{trt(trt-1)}
positive integers.
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 should be checked by the user applying isGYD
.
A matrix that represents the experimental design.
As indicated above, the returned design is not necessarily a BIBD design.
Oliver Sailer
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
# isGYD(find.BIB(5,5,3, 100))