diff --git a/R/symengine.R b/R/symengine.R
index 42347a807..b2a56f15c 100644
--- a/R/symengine.R
+++ b/R/symengine.R
@@ -264,7 +264,10 @@ regIfOrElse <- rex::rex(or(regIf, regElse))
   "rt" = 1
 )
 
-#' @inherit rxode2parse::rxFunParse
+#' Add/Create C functions for use in rxode2
+#'
+#' @inheritParams rxode2parse::rxFunParse
+#'
 #' @param name This can either give the name of the user function or
 #'   be a simple R function that you wish to convert to C.  If you
 #'   have rxode2 convert the R function to C, the name of the function
@@ -272,6 +275,7 @@ regIfOrElse <- rex::rex(or(regIf, regElse))
 #'   will match the R function provided.  Hence, if you are providing
 #'   an R function for conversion to C, the rest of the arguments are
 #'   implied.
+#' @export
 #' @examples
 #' \donttest{
 #' ## Right now rxode2 is not aware of the function fun
@@ -361,7 +365,6 @@ regIfOrElse <- rex::rex(or(regIf, regElse))
 #' rm(gg)
 #' rm(f)
 #' }
-#' @export
 rxFun <- function(name, args, cCode) {
   if (missing(args) && missing(cCode)) {
     .funName <- as.character(substitute(name))
@@ -3489,6 +3492,19 @@ rxSupportedFuns <- function() {
   }
 }
 
+#' Calculate derivatives/C code from a R function
+#'
+#' @param fun Function to convert to C
+#'
+#' @param name function name to convert to C, implied if needed
+#'
+#' @param onlyF Only calculate the C for the function, don't calculate the derivatives
+#'
+#' @return A list with C code and derivative information
+#'
+#' @keywords internal
+#'
+#' @noRd
 rxFun2c <- function(fun, name, onlyF=FALSE) {
   .env <- new.env(parent=emptyenv())
   .env$vars <- character(0)
@@ -3577,10 +3593,6 @@ rxFun2c <- function(fun, name, onlyF=FALSE) {
       .v <- eval(str2lang(.v))
       .dName <-  paste0("rx_", .funName, "_d_", v)
       .v <- rxFun2c(.v, .dName, onlyF=TRUE)
-      #' function(a, b, c) {
-      #'     paste0("2*", a, "+", b)
-      #'   },
-      #'
       .v2 <- paste0("function(", paste(.env$args, collapse=", "), "){\n",
                   "paste0(\"", .dName, "(\", ",
                   paste(.env$args, collapse=", \", \", "), ", \")\")",
diff --git a/inst/include/rxode2_control.h b/inst/include/rxode2_control.h
index fec561cf8..e54cb3dc8 100644
--- a/inst/include/rxode2_control.h
+++ b/inst/include/rxode2_control.h
@@ -2,5 +2,100 @@
 #ifndef __rxode2_control_H__
 #define __rxode2_control_H__
 #include <rxode2parse_control.h>
-
+#define Rxc_scale 0
+#define Rxc_method 1
+#define Rxc_atol 2
+#define Rxc_rtol 3
+#define Rxc_maxsteps 4
+#define Rxc_hmin 5
+#define Rxc_hmax 6
+#define Rxc_hini 7
+#define Rxc_maxordn 8
+#define Rxc_maxords 9
+#define Rxc_covsInterpolation 10
+#define Rxc_addCov 11
+#define Rxc_returnType 12
+#define Rxc_sigma 13
+#define Rxc_sigmaDf 14
+#define Rxc_nCoresRV 15
+#define Rxc_sigmaIsChol 16
+#define Rxc_sigmaSeparation 17
+#define Rxc_sigmaXform 18
+#define Rxc_nDisplayProgress 19
+#define Rxc_amountUnits 20
+#define Rxc_timeUnits 21
+#define Rxc_addDosing 22
+#define Rxc_stateTrim 23
+#define Rxc_updateObject 24
+#define Rxc_omega 25
+#define Rxc_omegaDf 26
+#define Rxc_omegaIsChol 27
+#define Rxc_omegaSeparation 28
+#define Rxc_omegaXform 29
+#define Rxc_nSub 30
+#define Rxc_thetaMat 31
+#define Rxc_thetaDf 32
+#define Rxc_thetaIsChol 33
+#define Rxc_nStud 34
+#define Rxc_dfSub 35
+#define Rxc_dfObs 36
+#define Rxc_seed 37
+#define Rxc_nsim 38
+#define Rxc_minSS 39
+#define Rxc_maxSS 40
+#define Rxc_strictSS 41
+#define Rxc_infSSstep 42
+#define Rxc_istateReset 43
+#define Rxc_subsetNonmem 44
+#define Rxc_hmaxSd 45
+#define Rxc_maxAtolRtolFactor 46
+#define Rxc_from 47
+#define Rxc_to 48
+#define Rxc_by 49
+#define Rxc_length_out 50
+#define Rxc_iCov 51
+#define Rxc_keep 52
+#define Rxc_keepF 53
+#define Rxc_drop 54
+#define Rxc_warnDrop 55
+#define Rxc_omegaLower 56
+#define Rxc_omegaUpper 57
+#define Rxc_sigmaLower 58
+#define Rxc_sigmaUpper 59
+#define Rxc_thetaLower 60
+#define Rxc_thetaUpper 61
+#define Rxc_indLinPhiM 62
+#define Rxc_indLinPhiTol 63
+#define Rxc_indLinMatExpType 64
+#define Rxc_indLinMatExpOrder 65
+#define Rxc_idFactor 66
+#define Rxc_mxhnil 67
+#define Rxc_hmxi 68
+#define Rxc_warnIdSort 69
+#define Rxc_ssAtol 70
+#define Rxc_ssRtol 71
+#define Rxc_safeZero 72
+#define Rxc_sumType 73
+#define Rxc_prodType 74
+#define Rxc_sensType 75
+#define Rxc_linDiff 76
+#define Rxc_linDiffCentral 77
+#define Rxc_resample 78
+#define Rxc_resampleID 79
+#define Rxc_maxwhile 80
+#define Rxc_cores 81
+#define Rxc_atolSens 82
+#define Rxc_rtolSens 83
+#define Rxc_ssAtolSens 84
+#define Rxc_ssRtolSens 85
+#define Rxc_simVariability 86
+#define Rxc_nLlikAlloc 87
+#define Rxc_useStdPow 88
+#define Rxc_naTimeHandle 89
+#define Rxc_addlKeepsCov 90
+#define Rxc_addlDropSs 91
+#define Rxc_ssAtDoseTime 92
+#define Rxc_ss2cancelAllPending 93
+#define Rxc_envir 94
+#define Rxc__zeros 95
 #endif // __rxode2_control_H__
diff --git a/man/as.rxUi.Rd b/man/as.rxUi.Rd
index f54aeb03f..3256eec73 100644
--- a/man/as.rxUi.Rd
+++ b/man/as.rxUi.Rd
@@ -10,25 +10,22 @@
 \alias{as.rxUi.default}
 \title{As rxode2 ui}
 \usage{
-as.rxUi(x, envir = parent.frame())
+as.rxUi(x)
 
-\method{as.rxUi}{rxode2}(x, envir = parent.frame())
+\method{as.rxUi}{rxode2}(x)
 
-\method{as.rxUi}{rxode2tos}(x, envir = parent.frame())
+\method{as.rxUi}{rxode2tos}(x)
 
-\method{as.rxUi}{rxModelVars}(x, envir = parent.frame())
+\method{as.rxUi}{rxModelVars}(x)
 
-\method{as.rxUi}{`function`}(x, envir = parent.frame())
+\method{as.rxUi}{`function`}(x)
 
-\method{as.rxUi}{rxUi}(x, envir = parent.frame())
+\method{as.rxUi}{rxUi}(x)
 
-\method{as.rxUi}{default}(x, envir = parent.frame())
+\method{as.rxUi}{default}(x)
 }
 \arguments{
 \item{x}{Object to convert to \code{rxUi} object}
-
-\item{envir}{is the environment to look for R user functions
-(defaults to parent environment)}
 }
 \value{
 rxUi object (or error if it cannot be converted)
@@ -40,7 +37,7 @@ As rxode2 ui
 
 mod1 <- function() {
  ini({
-   # central
+   # central 
    KA=2.94E-01
    CL=1.86E+01
    V2=4.02E+01
@@ -50,7 +47,7 @@ mod1 <- function() {
    # effects
    Kin=1
    Kout=1
-   EC50=200
+   EC50=200 
  })
  model({
    C2 <- centr/V2
diff --git a/man/reexports.Rd b/man/reexports.Rd
index 365c14ab7..f1310e9e9 100644
--- a/man/reexports.Rd
+++ b/man/reexports.Rd
@@ -82,4 +82,3 @@ below to see their documentation.
   \item{rxode2random}{\code{\link[rxode2random:dot-cbindOme]{.cbindOme}}, \code{\link[rxode2random:dot-expandPars]{.expandPars}}, \code{\link[rxode2random:dot-vecDf]{.vecDf}}, \code{\link[rxode2random]{cvPost}}, \code{\link[rxode2random]{invWR1d}}, \code{\link[rxode2random]{phi}}, \code{\link[rxode2random]{rinvchisq}}, \code{\link[rxode2random]{rLKJ1}}, \code{\link[rxode2random]{rxGetSeed}}, \code{\link[rxode2random]{rxGetSeed}}, \code{\link[rxode2random]{rxRmvn}}, \code{\link[rxode2random]{rxSeedEng}}, \code{\link[rxode2random]{rxSetSeed}}, \code{\link[rxode2random]{rxSetSeed}}, \code{\link[rxode2random]{rxSetSeed}}, \code{\link[rxode2random:rxWithSeed]{rxWithPreserveSeed}}, \code{\link[rxode2random]{rxWithSeed}}, \code{\link[rxode2random]{rxWithSeed}}}
 }}
 
-\value{ Inherited from parent routine }
diff --git a/man/rxFun.Rd b/man/rxFun.Rd
index 836a7fc2a..77c8e3c6f 100644
--- a/man/rxFun.Rd
+++ b/man/rxFun.Rd
@@ -3,7 +3,7 @@
 \name{rxFun}
 \alias{rxFun}
 \alias{rxRmFun}
-\title{Add user function to rxode2}
+\title{Add/Create C functions for use in rxode2}
 \usage{
 rxFun(name, args, cCode)
 
@@ -22,14 +22,8 @@ implied.}
 
 \item{cCode}{This is the C-code for the new function}
 }
-\value{
-nothing
-}
 \description{
-This adds a user function to rxode2 that can be called.  If needed,
-these functions can be differentiated by numerical differences or
-by adding the derivatives to rxode2's internal derivative table
-with rxode2's \code{rxD} function
+Add/Create C functions for use in rxode2
 }
 \examples{
 \donttest{
@@ -121,6 +115,3 @@ rm(gg)
 rm(f)
 }
 }
-\author{
-Matthew L. Fidler
-}
diff --git a/man/rxS.Rd b/man/rxS.Rd
index 898eca1ff..b55404472 100644
--- a/man/rxS.Rd
+++ b/man/rxS.Rd
@@ -4,7 +4,7 @@
 \alias{rxS}
 \title{Load a model into a symengine environment}
 \usage{
-rxS(x, doConst = TRUE, promoteLinSens = FALSE)
+rxS(x, doConst = TRUE, promoteLinSens = FALSE, envir = parent.frame())
 }
 \arguments{
 \item{x}{rxode2 object}
@@ -13,6 +13,9 @@ rxS(x, doConst = TRUE, promoteLinSens = FALSE)
 
 \item{promoteLinSens}{Promote solved linear compartment systems to
 sensitivity-based solutions.}
+
+\item{envir}{default is \code{NULL}; Environment to put symengine
+variables in.}
 }
 \value{
 rxode2/symengine environment
diff --git a/man/rxSolve.Rd b/man/rxSolve.Rd
index 54f0a6d80..f90f627a3 100644
--- a/man/rxSolve.Rd
+++ b/man/rxSolve.Rd
@@ -144,7 +144,8 @@ rxSolve(
   inits = NULL,
   ...,
   theta = NULL,
-  eta = NULL
+  eta = NULL,
+  envir = parent.frame()
 )
 
 \method{rxSolve}{rxUi}(
@@ -194,7 +195,8 @@ rxSolve(
   inits = NULL,
   ...,
   theta = NULL,
-  eta = NULL
+  eta = NULL,
+  envir = parent.frame()
 )
 
 \method{update}{rxSolve}(object, ...)
diff --git a/man/rxode2.Rd b/man/rxode2.Rd
index 0fa54404b..1a7a3c176 100644
--- a/man/rxode2.Rd
+++ b/man/rxode2.Rd
@@ -180,7 +180,7 @@ consisting of the following list of strings and functions:
 
       `atol`: a numeric absolute tolerance (1e-08 by default);
 
-      `rtol`: a numeric relative tolerance (1e-06 by default).e
+      `rtol`: a numeric relative tolerance (1e-06 by default).
 
       The output of \\dQuote\{solve\} is a matrix with as many rows as there
       are sampled time points and as many columns as system variables
@@ -232,9 +232,6 @@ mod <- rxode2(\{
   d/dt(centr) <- F*KA*depot - CL*C2 - Q*C2 + Q*C3;
 \})
 }\if{html}{\out{</div>}}
-
-\if{html}{\out{<div class="sourceCode">}}\preformatted{## using C compiler: ‘gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0’
-}\if{html}{\out{</div>}}
 \itemize{
 \item Inside a \code{rxode2("")} string statement:
 }\if{html}{\out{
@@ -250,9 +247,6 @@ mod <- rxode2(\{
   d/dt(centr) <- F*KA*depot - CL*C2 - Q*C2 + Q*C3;
 ")
 }\if{html}{\out{</div>}}
-
-\if{html}{\out{<div class="sourceCode">}}\preformatted{## using C compiler: ‘gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0’
-}\if{html}{\out{</div>}}
 \itemize{
 \item In a file name to be loaded by rxode2:
 }\if{html}{\out{
@@ -331,9 +325,7 @@ compilation model.
 \if{html}{\out{<div class="sourceCode r">}}\preformatted{mod$simulationModel
 }\if{html}{\out{</div>}}
 
-\if{html}{\out{<div class="sourceCode">}}\preformatted{## using C compiler: ‘gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0’
-
-## rxode2 2.0.14.9000 model named rx_78dcb8ef8275ff5e33a47163f4239e19 model (ready). 
+\if{html}{\out{<div class="sourceCode">}}\preformatted{## rxode2 2.0.14.9000 model named rx_8223e497c83db9e334c52254bd575c98 model (ready). 
 ## x$state: depot, center
 ## x$stateExtra: cp
 ## x$params: tka, tcl, tv, add.sd, eta.ka, eta.cl, eta.v, rxerr.cp
@@ -344,9 +336,7 @@ compilation model.
 mod$simulationIniModel
 }\if{html}{\out{</div>}}
 
-\if{html}{\out{<div class="sourceCode">}}\preformatted{## using C compiler: ‘gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0’
-
-## rxode2 2.0.14.9000 model named rx_baef7cfc602529d2843782858fc2f522 model (ready). 
+\if{html}{\out{<div class="sourceCode">}}\preformatted{## rxode2 2.0.14.9000 model named rx_182c47efea379394bbab84d957305170 model (ready). 
 ## x$state: depot, center
 ## x$stateExtra: cp
 ## x$params: tka, tcl, tv, add.sd, eta.ka, eta.cl, eta.v, rxerr.cp