fixed bug with formula evaluation

Author: dbarneche

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: bayesnec
 Title: A Bayesian No-Effect- Concentration (NEC) Algorithm
-Version: 2.0.2.2
+Version: 2.0.2.3
 Authors@R: c(person("Rebecca", "Fisher", email = "r.fisher@aims.gov.au", role = c("aut", "cre")), person("Diego","Barneche",role="aut"), person("Gerard","Ricardo",role="aut"), person("David","Fox",role="aut"))
 Description: Implementation of No-Effect-Concentration estimation that uses 'brms' (see Burkner (2017)<doi:10.18637/jss.v080.i01>; Burkner (2018)<doi:10.32614/RJ-2018-017>; Carpenter 'et al.' (2017)<doi:10.18637/jss.v076.i01> to fit concentration(dose)-response data using Bayesian methods for the purpose of estimating 'ECX' values, but more particularly 'NEC' (see Fox (2010)<doi:10.1016/j.ecoenv.2009.09.012>. This package expands and supersedes an original version implemented in R2jags, see Fisher, Ricardo and Fox (2020)<doi:10.5281/ZENODO.3966864>.
 Depends:

R/bayesnecformula.R

@@ -253,7 +253,7 @@ check_formula.default <- function(formula, data, run_par_checks = FALSE) {
     stop("You must specify which non-linear function to use with crf.",
          " See ?bayesnecformula")
   }
-  crf_vars <- all.vars(str2lang(x_str))
+  crf_vars <- all.vars(str2lang(eval(parse(text = x_str))))
   if (length(crf_vars) != 1) {
     stop("The `crf` term in your formula can only have one variable; you",
          " specified ", paste0(crf_vars, collapse = "; "), ".")