fix

R/compute_variances.R

@@ -285,14 +285,17 @@
       attr(vc2, "correlation") <- stats::cov2cor(model$D[vc_zi, vc_zi, drop = FALSE])
     }
 
+    model_deviance <- get_deviance(model, verbose = FALSE)
+    residual_df <- get_df(model, type = "residual", verbose = FALSE)
+
     vc1 <- list(vc1)
     names(vc1) <- re_names[[1]]
-    attr(vc1, "sc") <- sqrt(get_deviance(model, verbose = FALSE) / get_df(model, type = "residual", verbose = FALSE))
+    attr(vc1, "sc") <- sqrt(abs(model_deviance) / residual_df)
 
     if (!is.null(vc2)) {
       vc2 <- list(vc2)
       names(vc2) <- re_names[[2]]
-      attr(vc2, "sc") <- sqrt(get_deviance(model, verbose = FALSE) / get_df(model, type = "residual", verbose = FALSE))
+      attr(vc2, "sc") <- sqrt(abs(model_deviance) / residual_df)
     }
 
     vcorr <- compact_list(list(vc1, vc2))

R/get_sigma.R

@@ -275,9 +275,11 @@ get_sigma <- function(x, ci = NULL, verbose = TRUE) {
   }
 
   if (is_empty_object(s)) {
-    s <- .safe(
-      sqrt(get_deviance(x, verbose = verbose) / get_df(x, type = "residual", verbose = verbose))
-    )
+    s <- .safe({
+      model_deviance <- get_deviance(x, verbose = verbose)
+      residual_df <- get_df(x, type = "residual", verbose = verbose)
+      sqrt(abs(model_deviance) / residual_df)
+    })
   }
 
   if (is_empty_object(s)) {

R/null_model.R

@@ -64,6 +64,8 @@ null_model <- function(model, verbose = TRUE, ...) {
   if (inherits(model, "MixMod")) {
     nullform <- stats::as.formula(paste(find_response(model), "~ 1"))
     null.model <- suppressWarnings(stats::update(model, fixed = nullform))
+    # fix fixed effects formula
+    null.model$call$fixed <- nullform
   } else if (inherits(model, "cpglmm")) {
     nullform <- find_formula(model, verbose = FALSE)[["random"]]
     null.model <- suppressWarnings(stats::update(model, nullform))