unsupervised adaptation analysis

Generate standard errors for predictions of a mixed effects model, based on the variance-covariance matrices of the fixed effects. Returns the standard error, (square root of variance), of the predictions by default, but can return the full variance-covariance matrix

1 2	predict_se(fit, dat = NA, mm = mer_model_matrix(fit, dat), full_covar = FALSE)

`fit`	Fitted merMod object
`dat`	Data to generate fixed effects standard errors for
`full_covar`	(Default: FALSE) Whether to return the full covariance matrix (instead of just the square root of the diagonal elements)