1 files changed, 3 insertions, 0 deletions
diff --git a/R/drfit.R b/R/drfit.R
index ad7d16c..7fa53bf 100644
--- a/R/drfit.R
+++ b/R/drfit.R
@@ -41,6 +41,9 @@ drfit <- function(data, startlogED50 = NA, chooseone=TRUE,
             unit <- ""
             message("\n",i,": No data\n")
         }
+        if (length(unit) == 0) {
+            unit <- NA
+        }
         if (length(unit) > 1) {
             message("More than one unit for substance ",i,", halting\n\n")
             break