The
Filter to Select Markers for PCA
field is an optional parameter that
enables you to specify
marker variables
to use for the calculation of
principal components
for individuals. By default, all marker
variables
are used in the PCA.
You can type one or more statements to select markers to use for the PCA based on variables in the
annotation data set
. Only markers that meet the condition(s) specified are used to compute principal components for individuals. All Marker Variables are still included in the Q-K mixed model.
Important
: You still must specify all variables that correspond to the markers in the entire annotation data set as
Marker Variables
.
For example, to filter only diseased individuals from a data set containing a mixed
population
of diseased (sick) and healthy (healthy) individuals (as indicated in a column named
DiseaseStatus
), you could use the following simple WHERE expression:
Note:
The word
where
has already been entered for you.
