is-estimable {doBy} | R Documentation |
Determines if contrasts are estimable.
Description
Determines if contrasts are estimable, that is, if the contrasts can be written as a linear function of the data.
Usage
is_estimable(K, null.basis)
Arguments
K |
A matrix. |
null.basis |
A basis for a null space (can be found with
|
Details
Consider the setting . A linear function of
,
say
is estimable if and only if there exists an
such
that
or equivalently
. Hence
must be in
the column space of
, i.e. in the orthogonal complement of the
null space of
. Hence, with a basis
for the null space,
is_estimable()
checks if each row of the matrix
is
perpendicular to each column basis vector in
.
Value
A logical vector.
Author(s)
Søren Højsgaard, sorenh@math.aau.dk
References
http://web.mit.edu/18.06/www/Essays/newpaper_ver3.pdf
See Also
Examples
## TO BE WRITTEN
[Package doBy version 4.6.22 Index]