diff --git a/R/greedyMix.R b/R/greedyMix.R
index 2300494..344f966 100644
--- a/R/greedyMix.R
+++ b/R/greedyMix.R
@@ -398,69 +398,3 @@ greedyMix <- function(
 # 	i2 = rand_disc(y);   % uusi kori
 # 	suurin = muutokset(i2);
 
-
-# 	%--------------------------------------------------------------------------------------
-
-
-# 	function svar=rand_disc(CDF)
-# 	%returns an index of a value from a discrete distribution using inversion method
-# 	slump=rand;
-# 	har=find(CDF>slump);
-# 	svar=har(1);
-
-# %----------------------------------------------------------------------------------
-
-# 	function T = clusternum(X, T, k, c)
-# 	m = size(X,1)+1;
-# 	while(~isempty(k))
-# 	   % Get the children of nodes at this level
-# 	   children = X(k,1:2);
-# 	   children = children(:);
-
-# 	   % Assign this node number to leaf children
-# 	   t = (children<=m);
-# 	   T(children(t)) = c;
-
-# 	   % Move to next level
-# 	   k = children(~t) - m;
-# 	end
-
-# 	%----------------------------------------------------------------------------------------
-
-
-# 	function [Z, distances]=getDistances(data_matrix,nclusters)
-
-# 	%finds initial admixture clustering solution with nclusters clusters, uses simple mean Hamming distance
-# 	%gives partition in 8-bit format
-# 	%allocates all alleles of a single individual into the same basket
-# 	%data_matrix contains #Loci+1 columns, last column indicate whose alleles are placed in each row,
-# 	%i.e. ranges from 1 to #individuals. For diploids there are 2 rows per individual, for haploids only a single row
-# 	%missing values are indicated by zeros in the partition and by negative integers in the data_matrix.
-
-# 	size_data=size(data_matrix);
-# 	nloci=size_data(2)-1;
-# 	n=max(data_matrix(:,end));
-# 	distances=zeros(nchoosek(n,2),1);
-# 	pointer=1;
-# 	for i=1:n-1
-# 		i_data=data_matrix(find(data_matrix(:,end)==i),1:nloci);
-# 		for j=i+1:n
-# 			d_ij=0;
-# 			j_data=data_matrix(find(data_matrix(:,end)==j),1:nloci);
-# 			vertailuja = 0;
-# 			for k=1:size(i_data,1)
-# 				for l=1:size(j_data,1)
-# 					here_i=find(i_data(k,:)>=0);
-# 					here_j=find(j_data(l,:)>=0);
-# 					here_joint=intersect(here_i,here_j);
-# 					vertailuja = vertailuja + length(here_joint);
-# 					d_ij = d_ij + length(find(i_data(k,here_joint)~=j_data(l,here_joint)));
-# 				end
-# 			end
-# 			d_ij = d_ij / vertailuja;
-# 			distances(pointer)=d_ij;
-# 			pointer=pointer+1;
-# 		end
-# 	end
-
-# 	Z=linkage(distances');
\ No newline at end of file
diff --git a/R/matlab2r.R b/R/matlab2r.R
index aeda6b9..8583aff 100644
--- a/R/matlab2r.R
+++ b/R/matlab2r.R
@@ -1,16 +1,30 @@
 #' @title Convert Matlab function to R
 #' @description Performs basic syntax conversion from Matlab to R
 #' @param filename name of the file
-#' @param output can be "asis", "clean" (default) or "save"
+#' @param output can be "asis", "clean" (default), "save" or "append"
 #' @param improve_formatting if `TRUE` (default), makes minor changes
 #' to conform to best-practice formatting conventions
+#' @param change_assignment if `TRUE` (default), uses `<-` as the assignment operator
+#' @param append if `FALSE` (default), overwrites file; otherwise, append
+#' output to input
 #' @return text converted to R, printed to screen or replacing input file
 #' @author Waldir Leoncio
 #' @importFrom utils write.table
 #' @export
+#' @note This function is intended to expedite the process of converting a
+#' Matlab function to R by making common replacements. It does not have the
+#' immediate goal of outputting a ready-to-use function. In other words,
+#' after using this function you should go back to it and make minor changes.
+#'
+#' It is also advised to do a dry-run with `output = "clean"` and only switching
+#' to `output = "save"` when you are confident that no important code will be
+#' lost (for shorter functions, a careful visual inspection should suffice).
 matlab2r <- function(
-	filename, output = "clean", improve_formatting=TRUE
+	filename, output = "clean", improve_formatting=TRUE, change_assignment=TRUE,
+	append=FALSE
 ) {
+	# TODO: this function is too long! Split into subfunctions
+	# (say, by rule and/or section)
 	# ======================================================== #
 	# Verification                                             #
 	# ======================================================== #
@@ -30,10 +44,10 @@ matlab2r <- function(
 
 	# Function header ---------------------------------------- #
 	out <- gsub(
-		pattern     = "\\t*function (.+)\\s*=\\s*(.+)\\((.+)\\)",
+		pattern     = "\\t*function (\\S+)\\s*=\\s*(.+)\\((.+)\\)",
 		replacement = "\treturn(\\1)",
 		x           = txt[1]
-	)
+	) # TODO: improve by detecting listed outputs
 	txt <- gsub(
 		pattern     = "\\t*function (.+)\\s*=\\s*(.+)\\((.+)\\)",
 		replacement = "\\2 <- function(\\3) {",
@@ -59,9 +73,19 @@ matlab2r <- function(
 
 	# MATLAB-equivalent functions in R
 	txt <- gsub("gamma_ln", "log_gamma", txt)
+	txt <- gsub("nchoosek", "choose", txt)
+	txt <- gsub("isempty", "is.null", txt)
+	# txt <- gsub("(.+)\\'", "t(\\1)", txt)
 
 	# Subsets ------------------------------------------------ #
-	txt <- gsub("([^\\(]+)\\((.+)\\)\\s?=(.+)", "\\1[\\2] <- \\3", txt)
+	ass_op <- ifelse(change_assignment, "<-", "=")
+	txt <- gsub(
+		pattern = "([^\\(]+)\\(([^\\(]+)\\)=(.+)",
+		replacement = paste0("\\1[\\2] ", ass_op, "\\3"),
+		x = txt
+	)
+	txt <- gsub("\\(:\\)", "[, ]", txt)
+	txt <- gsub("(.+)(\\[|\\():,end(\\]|\\()", "\\1[, ncol()]", txt)
 
 	# Formatting --------------------------------------------- #
 	if (improve_formatting) {
@@ -71,9 +95,21 @@ matlab2r <- function(
 		txt <- gsub("(\\S)\\-(\\S)", "\\1 - \\2", txt)
 		txt <- gsub("(\\S)\\*(\\S)", "\\1 * \\2", txt)
 		# Logic operators
-		txt <- gsub("\\(~", "(!", txt)
+		txt <- gsub("~", "!", txt)
+		txt <- gsub("(\\S)>=(\\S)", "\\1 >= \\2", txt)
+		txt <- gsub("(\\S)<=(\\S)", "\\1 <= \\2", txt)
+		txt <- gsub("(\\S)==(\\S)", "\\1 == \\2", txt)
 		# Assignment
-		txt <- gsub("(.+)\\s?=\\s?(.+)", "\\1 <- \\2", txt)
+		txt <- gsub(
+			pattern = "(\\w)(\\s?)=(\\s?)(\\w)",
+			replacement = paste0("\\1 ", ass_op, " \\4"),
+			x = txt
+		)
+		# txt <- gsub(
+		# 	pattern = "(\\s+(.|\\_|\\[|\\])+)(\\s?)=(\\s?)(.+)",
+		# 	replacement = paste0("\\1 ", ass_op, "\\5"),
+		# 	x = txt
+		# )
 	}
 
 	# Adding output and end-of-file brace -------------------- #
@@ -84,15 +120,18 @@ matlab2r <- function(
 		return(txt)
 	} else if (output == "clean") {
 		return(cat(txt, sep="\n"))
-	} else {
+	} else if (output == "save") {
 		return(
 			write.table(
 				x         = txt,
 				file      = filename,
 				quote     = FALSE,
 				row.names = FALSE,
-				col.names = FALSE
+				col.names = FALSE,
+				append    = append
 			)
 		)
+	} else {
+		stop ("Invalid output argument")
 	}
 }
diff --git a/R/rand_disc.R b/R/rand_disc.R
new file mode 100644
index 0000000..e75f1c4
--- /dev/null
+++ b/R/rand_disc.R
@@ -0,0 +1,7 @@
+rand_disc <- function(CDF) {
+	# %returns an index of a value from a discrete distribution using inversion method
+	slump <- rand
+	har <- find(CDF > slump)
+	svar <- har(1)
+	return(svar)
+}
diff --git a/man/matlab2r.Rd b/man/matlab2r.Rd
index 6088487..2ae7c67 100644
--- a/man/matlab2r.Rd
+++ b/man/matlab2r.Rd
@@ -4,15 +4,26 @@
 \alias{matlab2r}
 \title{Convert Matlab function to R}
 \usage{
-matlab2r(filename, output = "clean", improve_formatting = TRUE)
+matlab2r(
+  filename,
+  output = "clean",
+  improve_formatting = TRUE,
+  change_assignment = TRUE,
+  append = FALSE
+)
 }
 \arguments{
 \item{filename}{name of the file}
 
-\item{output}{can be "asis", "clean" (default) or "save"}
+\item{output}{can be "asis", "clean" (default), "save" or "append"}
 
 \item{improve_formatting}{if `TRUE` (default), makes minor changes
 to conform to best-practice formatting conventions}
+
+\item{change_assignment}{if `TRUE` (default), uses `<-` as the assignment operator}
+
+\item{append}{if `FALSE` (default), overwrites file; otherwise, append
+output to input}
 }
 \value{
 text converted to R, printed to screen or replacing input file
@@ -20,6 +31,16 @@ text converted to R, printed to screen or replacing input file
 \description{
 Performs basic syntax conversion from Matlab to R
 }
+\note{
+This function is intended to expedite the process of converting a
+Matlab function to R by making common replacements. It does not have the
+immediate goal of outputting a ready-to-use function. In other words,
+after using this function you should go back to it and make minor changes.
+
+It is also advised to do a dry-run with `output = "clean"` and only switching
+to `output = "save"` when you are confident that no important code will be
+lost (for shorter functions, a careful visual inspection should suffice).
+}
 \author{
 Waldir Leoncio
 }