diff --git a/.development/PSO.cpp b/.development/PSO.cpp
new file mode 100644
index 0000000..c0ac392
--- /dev/null
+++ b/.development/PSO.cpp
@@ -0,0 +1,190 @@
+// [[Rcpp::depends(ast2ast)]]
+// [[Rcpp::depends(RcppArmadillo)]]
+// [[Rcpp::plugins(cpp2a)]]
+#include "etr.hpp"
+
+using namespace Rcpp;
+using namespace arma;
+
+// Define the PSO function
+// [[Rcpp::export]]
+List pso(const vec &lb, const vec &ub, Function loss, int ngen, int npop,
+         double error_threshold) {
+  int npar = lb.n_elem;
+  mat swarm = randu<mat>(npop, npar);
+  mat v = zeros<mat>(npop, npar);
+  vec swarm_bests = zeros<vec>(npop);
+  vec swarm_errors = zeros<vec>(npop);
+
+  const double initial_cog = 2.5;
+  const double final_cog = 0.5;
+  const double initial_soc = 0.5;
+  const double final_soc = 2.5;
+  const double w_max = 0.9;
+  const double w_min = 0.4;
+
+  for (int i = 0; i < npop; ++i) {
+    swarm.row(i) = (randu<rowvec>(npar) % (ub.t() - lb.t())) + lb.t();
+    swarm_errors[i] = as<double>(loss(swarm.row(i).t()));
+    swarm_bests[i] = swarm_errors[i];
+  }
+
+  uword global_best = index_min(swarm_bests);
+  rowvec global_best_vec = swarm.row(global_best);
+  double global_best_error = swarm_bests[global_best];
+  mat swarm_best_params = swarm;
+
+  auto correctBounds = [](const rowvec &target, const vec &lb, const vec &ub) {
+    rowvec res(target.size());
+    for (size_t i = 0; i < lb.size(); i++) {
+      if (target(i) < lb(i)) {
+        res(i) = lb(i);
+      } else if (target(i) > ub(i)) {
+        res(i) = ub(i);
+      } else {
+        res(i) = target(i);
+      }
+    }
+    return res;
+  };
+
+  int iter = 0;
+  while (iter < ngen) {
+    double w = w_max - iter * (w_max - w_min) / ngen;
+    double cog = initial_cog - (initial_cog - final_cog) * (iter + 1) / ngen;
+    double soc = initial_soc - (initial_soc - final_soc) * (iter + 1) / ngen;
+
+    for (int i = 0; i < npop; ++i) {
+      rowvec local_best_vec = swarm.row(global_best);
+
+      v.row(i) =
+          w * v.row(i) +
+          cog * randu<double>() * (swarm_best_params.row(i) - swarm.row(i)) +
+          soc * randu<double>() * (local_best_vec - swarm.row(i));
+      swarm.row(i) += v.row(i);
+
+      swarm.row(i) = correctBounds(swarm.row(i), lb, ub);
+
+      double error = as<double>(loss(swarm.row(i).t()));
+
+      if (!std::isinf(error) && !std::isnan(error) && error < swarm_bests[i]) {
+        swarm_bests[i] = error;
+        swarm_best_params.row(i) = swarm.row(i);
+      }
+      if (!std::isinf(error) && !std::isnan(error) &&
+          error < global_best_error) {
+        global_best = i;
+        global_best_vec = swarm.row(i);
+        global_best_error = error;
+      }
+    }
+
+    iter++;
+
+    if (global_best_error < error_threshold) {
+      break;
+    }
+  }
+
+  double insilico = as<double>(loss(global_best_vec.t()));
+  return List::create(Named("insilico") = insilico,
+                      Named("global_best_vec") = global_best_vec);
+}
+
+typedef double (*FP)(etr::Vec<double> &a);
+
+// [[Rcpp::export]]
+List pso_xptr(const vec &lb, const vec &ub, Rcpp::XPtr<FP> loss_xptr, int ngen,
+              int npop, double error_threshold) {
+  FP loss = *loss_xptr;
+  int npar = lb.n_elem;
+  mat swarm = randu<mat>(npop, npar);
+  mat v = zeros<mat>(npop, npar);
+  vec swarm_bests = zeros<vec>(npop);
+  vec swarm_errors = zeros<vec>(npop);
+
+  const double initial_cog = 2.5;
+  const double final_cog = 0.5;
+  const double initial_soc = 0.5;
+  const double final_soc = 2.5;
+  const double w_max = 0.9;
+  const double w_min = 0.4;
+
+  etr::Vec<double> param(etr::SI{npar});
+
+  for (int i = 0; i < npop; ++i) {
+    swarm.row(i) = (randu<rowvec>(npar) % (ub.t() - lb.t())) + lb.t();
+    for (size_t j = 0; j < npar; j++) {
+      param[j] = swarm.row(i)(j);
+    }
+    swarm_errors[i] = loss(param);
+    swarm_bests[i] = swarm_errors[i];
+  }
+
+  uword global_best = index_min(swarm_bests);
+  rowvec global_best_vec = swarm.row(global_best);
+  double global_best_error = swarm_bests[global_best];
+  mat swarm_best_params = swarm;
+
+  auto correctBounds = [](const rowvec &target, const vec &lb, const vec &ub) {
+    rowvec res(target.size());
+    for (size_t i = 0; i < lb.size(); i++) {
+      if (target(i) < lb(i)) {
+        res(i) = lb(i);
+      } else if (target(i) > ub(i)) {
+        res(i) = ub(i);
+      } else {
+        res(i) = target(i);
+      }
+    }
+    return res;
+  };
+
+  int iter = 0;
+  while (iter < ngen) {
+    double w = w_max - iter * (w_max - w_min) / ngen;
+    double cog = initial_cog - (initial_cog - final_cog) * (iter + 1) / ngen;
+    double soc = initial_soc - (initial_soc - final_soc) * (iter + 1) / ngen;
+
+    for (int i = 0; i < npop; ++i) {
+      rowvec local_best_vec = swarm.row(global_best);
+
+      v.row(i) =
+          w * v.row(i) +
+          cog * randu<double>() * (swarm_best_params.row(i) - swarm.row(i)) +
+          soc * randu<double>() * (local_best_vec - swarm.row(i));
+      swarm.row(i) += v.row(i);
+
+      swarm.row(i) = correctBounds(swarm.row(i), lb, ub);
+      for (size_t j = 0; j < npar; j++) {
+        param[j] = swarm.row(i)(j);
+      }
+
+      double error = loss(param);
+
+      if (!std::isinf(error) && !std::isnan(error) && error < swarm_bests[i]) {
+        swarm_bests[i] = error;
+        swarm_best_params.row(i) = swarm.row(i);
+      }
+      if (!std::isinf(error) && !std::isnan(error) &&
+          error < global_best_error) {
+        global_best = i;
+        global_best_vec = swarm.row(i);
+        global_best_error = error;
+      }
+    }
+
+    iter++;
+
+    if (global_best_error < error_threshold) {
+      break;
+    }
+  }
+
+  for (size_t j = 0; j < npar; j++) {
+    param[j] = global_best_vec(j);
+  }
+  double insilico = loss(param);
+  return List::create(Named("insilico") = insilico,
+                      Named("global_best_vec") = global_best_vec);
+}
diff --git a/.development/Rplots.pdf b/.development/Rplots.pdf
new file mode 100644
index 0000000..b68921a
Binary files /dev/null and b/.development/Rplots.pdf differ
diff --git a/.development/benchmark.R b/.development/benchmark.R
new file mode 100644
index 0000000..1426d9f
--- /dev/null
+++ b/.development/benchmark.R
@@ -0,0 +1,51 @@
+setwd("/home/konrad/Documents/GitHub/RProjects/ast2ast_supplement/ast2ast/.development/")
+Rcpp::sourceCpp("PSO.cpp")
+
+
+rosenbrock <- function(parameter) {
+  value <- 0
+  for (i in 1:(length(parameter) - 1)) {
+    value <- value +
+      100 * (parameter[i + 1] - parameter[i]^2)^2 +
+      (1 - parameter[i])^2
+  }
+  return(value)
+}
+
+
+lb <- -10000
+ub <- 10000
+error_threshold <- 0.0000001
+npop <- 400
+
+pso(rep(lb, 3), rep(ub, 3), rosenbrock, 10000, npop, error_threshold)
+
+
+rosenbrock_cpp <- function(parameter) {
+  value::double <- 0
+  sz::int <- length(parameter)
+  for (i in 1:(sz - 1)) {
+    value <- value +
+      100 * (parameter[i + 1] - parameter[i]^2)^2 +
+      (1 - parameter[i])^2
+  }
+  return(value)
+}
+
+rosenbrock_cpp <- ast2ast::translate(rosenbrock_cpp,
+  output = "XPtr",
+  handle_inputs = "",
+  references = TRUE,
+  verbose = TRUE
+)
+
+pso_xptr(rep(lb, 3), rep(ub, 3), rosenbrock_cpp, 10000, npop, error_threshold)
+
+
+res <- microbenchmark::microbenchmark(
+  pso(rep(lb, 3), rep(ub, 3), rosenbrock, 10000, npop, error_threshold),
+  pso_xptr(rep(lb, 3), rep(ub, 3), rosenbrock_cpp, 10000, npop, error_threshold)
+)
+res
+
+boxplot(res)
diff --git a/.development/lorenz.c b/.development/lorenz.c
new file mode 100644
index 0000000..4612dad
--- /dev/null
+++ b/.development/lorenz.c
@@ -0,0 +1,20 @@
+/* file lorenz.c */
+#include <R.h>
+static double parms[3];
+#define a parms[0]
+#define b parms[1]
+#define c parms[2]
+
+/* initializer  */
+void initmod(void (*odeparms)(int *, double *)) {
+  int N = 3;
+  odeparms(&N, parms);
+}
+
+/* Derivatives */
+void derivs(int *neq, double *t, double *y, double *ydot, double *yout,
+            int *ip) {
+  ydot[0] = a * y[0] + y[1] * y[2];
+  ydot[1] = b * (y[1] - y[2]);
+  ydot[2] = -y[0] * y[1] + c * y[1] - y[2];
+}
diff --git a/.development/lorenz.cpp b/.development/lorenz.cpp
new file mode 100644
index 0000000..7ba6d57
--- /dev/null
+++ b/.development/lorenz.cpp
@@ -0,0 +1,39 @@
+// [[Rcpp::depends(ast2ast, RcppArmadillo)]]
+// [[Rcpp::plugins(cpp20)]]
+
+#include "etr.hpp"
+using namespace Rcpp;
+using namespace etr;
+
+static double parms[3];
+#define a parms[0]
+#define b parms[1]
+#define c parms[2]
+
+extern "C" {
+void initmod_a2a(void (*odeparms)(int *, double *));
+}
+
+extern "C" {
+void derivs_a2a(int *neq, double *t, double *y, double *ydot, double *yout,
+                int *ip);
+}
+
+void initmod_a2a(void (*odeparms)(int *, double *)) {
+  int N = 3;
+  odeparms(&N, parms);
+}
+
+void user_fct(double t, BorrowPtr &y, BorrowPtr &ydot) {
+  at(ydot, 1) = a * at(y, 1) + at(y, 2) * at(y, 3);
+  at(ydot, 2) = b * (at(y, 2) - at(y, 3));
+  at(ydot, 3) = -at(y, 1) * at(y, 2) + c * at(y, 2) - at(y, 3);
+}
+
+void derivs_a2a(int *neq, double *t, double *y, double *ydot, double *yout,
+                int *ip) {
+  BorrowPtr y_(y, *neq);
+  BorrowPtr ydot_(ydot, *neq);
+  double t_ = *t;
+  user_fct(t_, y_, ydot_);
+}
diff --git a/DESCRIPTION b/DESCRIPTION
index 85b289e..b62892b 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -12,6 +12,13 @@ License: GPL-2
 Imports: Rcpp (>= 1.0.4), R6, methods, pryr, rlang,  RcppArmadillo, purrr
 LinkingTo: Rcpp, RcppArmadillo
 VignetteBuilder: knitr
-Suggests: knitr, kableExtra, rmarkdown, tinytest, microbenchmark, ggplot2, RcppXPtrUtils
+Suggests: 
+  knitr,
+  kableExtra,
+  rmarkdown,
+  tinytest,
+  microbenchmark,
+  ggplot2,
+  RcppXPtrUtils
 Encoding: UTF-8
 RoxygenNote: 7.2.1
diff --git a/vignettes/InformationForPackageAuthors.Rmd b/vignettes/InformationForPackageAuthors.Rmd
index b3159c5..e76fc80 100644
--- a/vignettes/InformationForPackageAuthors.Rmd
+++ b/vignettes/InformationForPackageAuthors.Rmd
@@ -122,11 +122,13 @@ f <- function(a, b) {
   c <- a + b
   return(c)
 }
-fcpp <- ast2ast::translate(f, output = "XPtr", 
-                           types_of_args = c("double", "double"),
-                           data_structures = c("vector", "scalar"),
-                           handle_inputs = c("", ""),
-                           references = c(TRUE, TRUE))
+fcpp <- ast2ast::translate(f,
+  output = "XPtr",
+  types_of_args = c("double", "double"),
+  data_structures = c("vector", "scalar"),
+  handle_inputs = c("", ""),
+  references = c(TRUE, TRUE)
+)
 ```
 
 #### Afterwards the external pointer is used in an R package