Comparing Julia and R’s Vocabularies

While exploring the Julia manual recently, I realized that it might be helpful to put the basic vocabularies of Julia and R side-by-side for easy comparison. So I took Hadley Wickham’s R Vocabulary section from the book he’s putting together on the devtools wiki, put all of the functions Hadley listed into a CSV file, and proceeded to fill in entries where I knew of an obvious Julia equivalent to an R function. The results are on GitHub and, as they stand today, are shown below:

R	Julia	Category	Subcategory
https:// github.com/ hadley/devtools/ wiki/vocabulary	http:// julialang.org/ manual/ standard- library-reference/	Resources	Vocabulary
?	help	Basics	First Functions
str		Basics	First Functions
%in%		Basics	Operators
match		Basics	Operators
=	=	Basics	Operators
<-	=	Basics	Operators
<<-		Basics	Operators
assign		Basics	Operators
$	[]	Basics	Operators
[]	[]	Basics	Operators
[[]]	[]	Basics	Operators
replace		Basics	Operators
head		Basics	Operators
tail		Basics	Operators
subset		Basics	Operators
with		Basics	Operators
within		Basics	Operators
all.equal		Basics	Comparison
identical		Basics	Comparison
!=	!=	Basics	Comparison
==	==	Basics	Comparison
>	>	Basics	Comparison
>=	>=	Basics	Comparison
<	<	Basics	Comparison
<=	<=	Basics	Comparison
is.na		Basics	Comparison
is.nan		Basics	Comparison
is.finite		Basics	Comparison
complete.cases		Basics	Comparison
*	*	Basics	Basic Math
+	+	Basics	Basic Math
–	–	Basics	Basic Math
/	/	Basics	Basic Math
^	^	Basics	Basic Math
%%	mod (%%)	Basics	Basic Math
%/%	div	Basics	Basic Math
abs	abs	Basics	Basic Math
sign	sign	Basics	Basic Math
acos	acos	Basics	Basic Math
acosh	acosh	Basics	Basic Math
asin	asin	Basics	Basic Math
asinh	asinh	Basics	Basic Math
atan	atan	Basics	Basic Math
atan2	atan2	Basics	Basic Math
atanh	atanh	Basics	Basic Math
sin	sin	Basics	Basic Math
sinh	sinh	Basics	Basic Math
cos	cos	Basics	Basic Math
cosh	cosh	Basics	Basic Math
tan	tan	Basics	Basic Math
tanh	tanh	Basics	Basic Math
ceiling	ceil	Basics	Basic Math
floor	floor	Basics	Basic Math
round	round	Basics	Basic Math
trunc	trunc	Basics	Basic Math
signif		Basics	Basic Math
exp	exp	Basics	Basic Math
log	log	Basics	Basic Math
log10	log10	Basics	Basic Math
log1p	log1p	Basics	Basic Math
log2	log2	Basics	Basic Math
logb		Basics	Basic Math
sqrt	sqrt	Basics	Basic Math
cummax		Basics	Basic Math
cummin		Basics	Basic Math
cumprod	cumprod	Basics	Basic Math
cumsum	cumsum	Basics	Basic Math
diff	diff	Basics	Basic Math
max	max	Basics	Basic Math
min	min	Basics	Basic Math
prod	prod	Basics	Basic Math
sum	sum	Basics	Basic Math
range		Basics	Basic Math
mean	mean	Basics	Basic Math
median	median	Basics	Basic Math
cor	cor_pearson	Basics	Basic Math
cov	cov_pearson	Basics	Basic Math
sd	std	Basics	Basic Math
var	var	Basics	Basic Math
pmax		Basics	Basic Math
pmin		Basics	Basic Math
rle		Basics	Basic Math
function	function	Basics	Functions
missing		Basics	Functions
on.exit		Basics	Functions
return	return	Basics	Functions
invisible		Basics	Functions
&	&	Basics	Logical & Set Operations
|	|	Basics	Logical & Set Operations
!	!	Basics	Logical & Set Operations
xor		Basics	Logical & Set Operations
all	all	Basics	Logical & Set Operations
any	any	Basics	Logical & Set Operations
intersect	intersect	Basics	Logical & Set Operations
union	union	Basics	Logical & Set Operations
setdiff		Basics	Logical & Set Operations
setequal		Basics	Logical & Set Operations
which	find	Basics	Logical & Set Operations
c	[] ({})	Basics	Vectors and Matrices
matrix	[] ({})	Basics	Vectors and Matrices
length	size (length)	Basics	Vectors and Matrices
dim	size	Basics	Vectors and Matrices
ncol	size(x, 1)	Basics	Vectors and Matrices
nrow	size(x, 2)	Basics	Vectors and Matrices
cbind	hcat	Basics	Vectors and Matrices
rbind	vcat	Basics	Vectors and Matrices
names		Basics	Vectors and Matrices
colnames		Basics	Vectors and Matrices
rownames		Basics	Vectors and Matrices
t	‘	Basics	Vectors and Matrices
diag	eye	Basics	Vectors and Matrices
sweep		Basics	Vectors and Matrices
as.matrix		Basics	Vectors and Matrices
data.matrix		Basics	Vectors and Matrices
c	[] ({})	Basics	Making Vectors
rep		Basics	Making Vectors
seq	[from:by:to]	Basics	Making Vectors
seq_along		Basics	Making Vectors
seq_len	[1:len]	Basics	Making Vectors
rev	reverse	Basics	Making Vectors
sample		Basics	Making Vectors
choose	factorial	Basics	Making Vectors
factorial	factorial	Basics	Making Vectors
combn		Basics	Making Vectors
(is/as).(character/numeric/logical)		Basics	Making Vectors
list	HashTable ([])	Basics	Lists & Data Frames
unlist		Basics	Lists & Data Frames
data.frame		Basics	Lists & Data Frames
as.data.frame		Basics	Lists & Data Frames
split		Basics	Lists & Data Frames
expand.grid		Basics	Lists & Data Frames
if	if	Basics	Control Flow
&&	&&	Basics	Control Flow
||	||	Basics	Control Flow
for	for	Basics	Control Flow
while	while	Basics	Control Flow
next	continue	Basics	Control Flow
break	break	Basics	Control Flow
switch		Basics	Control Flow
ifelse		Basics	Control Flow
fitted		Statistics	Linear Models
predict		Statistics	Linear Models
resid		Statistics	Linear Models
rstandard		Statistics	Linear Models
lm		Statistics	Linear Models
glm		Statistics	Linear Models
hat		Statistics	Linear Models
influence.measures		Statistics	Linear Models
logLik		Statistics	Linear Models
df		Statistics	Linear Models
deviance		Statistics	Linear Models
formula		Statistics	Linear Models
~		Statistics	Linear Models
I		Statistics	Linear Models
anova		Statistics	Linear Models
coef		Statistics	Linear Models
confint		Statistics	Linear Models
vcov		Statistics	Linear Models
contrasts		Statistics	Linear Models
apropos(‘\\.test$’)		Statistics	Miscellaneous Statistical Tests
beta	beta	Statistics	Random Numbers
binom	binom	Statistics	Random Numbers
cauchy	cauchy	Statistics	Random Numbers
chisq	chisq	Statistics	Random Numbers
exp	exp	Statistics	Random Numbers
f	f	Statistics	Random Numbers
gamma	gamma	Statistics	Random Numbers
geom	geom	Statistics	Random Numbers
hyper	hyper	Statistics	Random Numbers
lnorm	lnorm	Statistics	Random Numbers
logis	logis	Statistics	Random Numbers
multinom	multinom	Statistics	Random Numbers
nbinom	nbinom	Statistics	Random Numbers
norm	norm	Statistics	Random Numbers
pois	pois	Statistics	Random Numbers
signrank	signrank	Statistics	Random Numbers
t	t	Statistics	Random Numbers
unif	unif (rand)	Statistics	Random Numbers
weibull	weibull	Statistics	Random Numbers
wilcox	wilcox	Statistics	Random Numbers
birthday	birthday	Statistics	Random Numbers
tukey	tukey	Statistics	Random Numbers
crossprod	*	Statistics	Matrix Algebra
tcrossprod	*	Statistics	Matrix Algebra
eigen	eig	Statistics	Matrix Algebra
qr	qr	Statistics	Matrix Algebra
svd	svd	Statistics	Matrix Algebra
%*%	*	Statistics	Matrix Algebra
%o%		Statistics	Matrix Algebra
outer		Statistics	Matrix Algebra
rcond		Statistics	Matrix Algebra
solve	\	Statistics	Matrix Algebra
duplicated		Statistics	Ordering and Tabulating
unique		Statistics	Ordering and Tabulating
merge		Statistics	Ordering and Tabulating
order		Statistics	Ordering and Tabulating
rank		Statistics	Ordering and Tabulating
quantile	quantile	Statistics	Ordering and Tabulating
sort	sort	Statistics	Ordering and Tabulating
table		Statistics	Ordering and Tabulating
ftable		Statistics	Ordering and Tabulating
ls	whos	Working with R	Workspace
exists		Working with R	Workspace
get		Working with R	Workspace
rm		Working with R	Workspace
getwd	getcwd	Working with R	Workspace
setwd	setcwd	Working with R	Workspace
q	Ctrl-D	Working with R	Workspace
source	load	Working with R	Workspace
install.packages		Working with R	Workspace
library		Working with R	Workspace
require		Working with R	Workspace
help	help	Working with R	Help
?	help	Working with R	Help
help.search		Working with R	Help
apropos		Working with R	Help
RSiteSearch		Working with R	Help
citation		Working with R	Help
demo		Working with R	Help
example		Working with R	Help
vignette		Working with R	Help
traceback		Working with R	Debugging
browser		Working with R	Debugging
recover		Working with R	Debugging
options(error =)		Working with R	Debugging
stop		Working with R	Debugging
warning		Working with R	Debugging
message		Working with R	Debugging
tryCatch	try/catch	Working with R	Debugging
try	try	Working with R	Debugging
print	print (println)	I/O	Output
cat		I/O	Output
message		I/O	Output
warning		I/O	Output
dput		I/O	Output
format		I/O	Output
sink		I/O	Output
data		I/O	Reading and Writing Data
count.fields		I/O	Reading and Writing Data
read.csv	csvread	I/O	Reading and Writing Data
read.delim	dlmread	I/O	Reading and Writing Data
read.fwf		I/O	Reading and Writing Data
read.table		I/O	Reading and Writing Data
library(foreign)		I/O	Reading and Writing Data
write.table	dlmwrite	I/O	Reading and Writing Data
readLines	readlines	I/O	Reading and Writing Data
writeLines		I/O	Reading and Writing Data
load		I/O	Reading and Writing Data
save		I/O	Reading and Writing Data
readRDS		I/O	Reading and Writing Data
saveRDS		I/O	Reading and Writing Data
dir		I/O	Files and Directories
basename		I/O	Files and Directories
dirname		I/O	Files and Directories
file.path		I/O	Files and Directories
path.expand		I/O	Files and Directories
file.choose		I/O	Files and Directories
file.copy		I/O	Files and Directories
file.create		I/O	Files and Directories
file.remove		I/O	Files and Directories
path.rename		I/O	Files and Directories
dir.create		I/O	Files and Directories
file.exists		I/O	Files and Directories
tempdir		I/O	Files and Directories
tempfile		I/O	Files and Directories
download.file		I/O	Files and Directories
ISOdate		Special Data	Date / Time
ISOdatetime		Special Data	Date / Time
strftime		Special Data	Date / Time
strptime		Special Data	Date / Time
date		Special Data	Date / Time
difftime		Special Data	Date / Time
julian		Special Data	Date / Time
months		Special Data	Date / Time
quarters		Special Data	Date / Time
weekdays		Special Data	Date / Time
library(lubridate)		Special Data	Date / Time
grep	match	Special Data	Character Manipulation
agrep		Special Data	Character Manipulation
gsub		Special Data	Character Manipulation
strsplit	split	Special Data	Character Manipulation
chartr		Special Data	Character Manipulation
nchar	strlen	Special Data	Character Manipulation
tolower		Special Data	Character Manipulation
toupper		Special Data	Character Manipulation
substr		Special Data	Character Manipulation
paste	join	Special Data	Character Manipulation
library(stringr)		Special Data	Character Manipulation
factor		Special Data	Factors
levels		Special Data	Factors
nlevels		Special Data	Factors
reorder		Special Data	Factors
relevel		Special Data	Factors
cut		Special Data	Factors
findInterval		Special Data	Factors
interaction		Special Data	Factors
options(stringsAsFactors = FALSE)		Special Data	Factors
array	[]	Special Data	Array Manipulation
dim	size	Special Data	Array Manipulation
dimnames		Special Data	Array Manipulation
aperm		Special Data	Array Manipulation
library(abind)		Special Data	Array Manipulation

I’d like to note that holes in the list of Julia functions can exist for several reasons:

1. The language does not yet have the relevant features. This is true of things like factor() or data.frame().
2. The language has draft implementations of the relevant features, but they are not yet ready to make their way into this list. This is true of Doug Bates’ GLM code, for example.
3. I simply don’t know what the Julia equivalent is for an R function, but it may well exist. If you know of one, please fork the GitHub repository I’m using and revise the CSV file appropriately. I’ll integrate relevant pull requests as soon as I can find time.

In addition to explaining the presence of the many holes you can see this in this list, I’d also like to note how quickly these holes are being filled in: Doug Bates already finished a wrapper for the Rmath library, which means that Julia now has tools for calculating the PDF’s, CDF’s, and inverse CDF’s of most statistical distributions as well as the ability to draw random samples from them. That means that almost any sort of MCMC you’d like to do is already possible in Julia. (I, for one, am really interested to see if someone will use Julia’s sparse matrix support and these new Rmath functions to build MCMC code that’s easy on the eyes while also running at an appropriately fast speed on complicated, big data problems like matrix factorizations.) On my end, I’ve been working on filling some of the missing entries in this list by adding in pieces that I think I understand well enough to implement from scratch, such as:

• Optimization algorithms (optim.jl):
• Simulated annealing
• Gradient descent
• Newton’s method
• Statistical hypothesis tests (stats.jl):
• t-Tests
• Utility functions (utils.jl):
• range
• keys
• cummax
• cummin