fcm creates a matrix with the correct number of columns to specify a constraint in the fixed effects using the Gtc argument of the vs function.
Usage
fcm(x)
Arguments
x
vector of 1's and 0's corresponding to the traits for which this fixed effect should be fitted. For example, for a trivariate model if the fixed effect "x" wants to be fitted only for trait 1 and 2 but not for the 3rd trait then you would use fcm(c(1,1,0)) in the Gtc argument of the vs() function.
Value
$res
a list with the provided vector and the variance covariance structure expected for the levels of the random effect.
References
Covarrubias-Pazaran G (2016) Genome assisted prediction of quantitative traits using the R package sommer. PLoS ONE 11(6): doi:10.1371/journal.pone.0156744
See Also
The function vs to know how to use fcm in the mmer solver.