diff --git a/DESCRIPTION b/DESCRIPTION
index a5902c3..9db9b55 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: DynACof
 Type: Package
 Title: Dynamic Crop Model to Simulate Coffee Crop Ecophysiology for Monospecific Stands or Agroforestry
-Version: 1.1.2
+Version: 1.2.0
 Date: 2019-03-14
 Authors@R: c(person("Remi", "Vezy",, "vezy.remi@gmail.com", c("aut", "cre", "cph"),comment = c(ORCID = "0000-0002-0808-1461")),
     person("Olivier", "Roupsard",, "olivier.roupsard@cirad.fr", c("aut", "cph")),
diff --git a/NEWS.md b/NEWS.md
index d7d5f7c..659d523 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,9 @@
+# DynACof 1.2.0
+
+* Reformat the code so the shade tree, coffee, soil and energy balance are made by separate functions sequentially  
+* Add dynacof_i to be able to change a simulation from one (or several) time step to another  
+* Add DynACof.jl compatibility: now the user can use the Julia version of DynACof directly from the R using the R version of the package. This functionnality require Julia (v > 1.1) to be installed on the computer and available in the path.  
+
 # DynACof 1.1.2
 
 * Externalize coffee metamodels to parameter file + remove Tcan_MAESPA_Coffee as it is computed by the model now
diff --git a/R/0-Functions.R b/R/0-Functions.R
index d863668..2fb4bf1 100644
--- a/R/0-Functions.R
+++ b/R/0-Functions.R
@@ -1016,7 +1016,8 @@ logistic= function(xi,u_log,s_log){1/(1+exp(-((xi-u_log)/s_log)))}
 #' @rdname logistic
 #' @export
 logistic_deriv= function(xi,u_log,s_log){
-  logistic(xi,u_log,s_log) * (1.0 - logistic(xi,u_log,s_log))
+  res= c(0,diff(xi))
+  (exp(-((xi-u_log)/s_log))/(s_log*(1+exp(-((xi-u_log)/s_log)))^2))*res
 }
 
 #' Fruit sucrose accumulation