Peter's Data Crunching Cheat Sheet

The design of advanced quantitative models and the implementation of complex data mining systems might be at the centre of my daily work. But even though, quite a considerable part of my time is actually spend crunching data: shuffling, sorting and scanning through data (which sometimes is not more than just eye-balling) in order to be able to understand and use it. Greg Wilson from the University of Toronto wrote a great book on Data Crunching, where most of the basic stuff is thoroughly explained and presented in a concise manner. But most of his code examples are in either Java or Python. I really enjoy working with those two languages but every now and then I do need to use some of the other languages and tools common to our trade. Therefore I've put together, as a reference for myself and others, a small collection of some basic data crunching routines in some common languages and tools:

Task	Java	Scala	C#	Python	Perl	Matlab	R	Julia	SPSS	SAS
writing to a file	writeFile.java	writeFile.scala	writeFile.cs	writeFile.py	writeFile.pm	writeCSV.M	writeCSV.R	writeFile.jl	writeCSV.sps	writeCSV.sas
reading from a file	readFile.java	readFile.scala	readFile.cs	readFile.py	readFile.pm	readCSV.M	readCSV.R	readFile.jl	readCSV.sps	readCSV.sas
containers	containers.java	containers.scala	containers.cs	containers.py	containers.pm	containers.M	containers.R	containers.jl	containers.sps	containers.sas
for loop	forLoop.java	forLoop.scala	forLoop.cs	forLoop.py	forLoop.pm	forLoop.M	forLoop.R	forLoop.jl	forLoop.sps	forLoop.sas
oo - concepts	ooConcepts.java	ooConcepts.scala	ooConcepts.cs	ooConcepts.py	ooConcepts.pm	ooConcepts.M	ooConcepts.R	ooConcepts.jl	ooConcepts.sps	ooConcepts.sas
database connection	database.java	database.scala	database.cs	database.py	database.pm	.	database.R	database.jl	database.sps	database.sas
random numbers	random.java	random.scala	random.cs	random.py	random.pm	random.M	random.R	random.jl	random.sps	random.sas
linear algebra	matrix.java	matrix.scala	matrix.cs	matrix.py	matrix.pm	matrix.M	matrix.R	matrix.jl	matrix.sps	matrix.sas
scatter plot	scatterPlot.java	scatterPlot.scala	scatterPlot.cs	scatterPlot.py	.	scatterPlot.M	scatterPlot.R	scatterPlot.jl	scatterPlot.sps	scatterPlot.sas
line chart	lineChart.java	lineChart.scala	lineChart.cs	lineChart.py	.	lineChart.M	lineChart.R	lineChart.jl	lineChart.sps	lineChart.sas
bar chart	barChart.java	barChart.scala	barChart.cs	barChart.py	.	barChart.M	barChart.R	barChart.jl	barChart.sps	barChart.sas
pie chart	pieChart.java	pieChart.scala	pieChart.cs	pieChart.py	.	pieChart.M	pieChart.R	.	pieChart.sps	pieChart.sas

Writing to a file

Java

//writeFile.java

try {

java.io.FileWriter writer = new java.io.FileWriter("C:/data/newFile.txt");
writer.write("line_1 \r\n");
writer.write("line_2 \r\n");
writer.flush();
writer.close();

} catch (java.io.IOException e) {

e.printStackTrace();

}

Scala

//writeFile.scala
//just using the java way of doing things

val file = new File("C:/data/newFile.txt")
val bw = new BufferedWriter(new FileWriter(file))
bw.write("line 1 \n")
bw.write("line 2 \n")
bw.close()

C#

//writeFile.cs
System.IO.TextWriter writer = new System.IO.StreamWriter("C:/data/newFile.txt");
writer.WriteLine("line_1");
writer.WriteLine("line_2");
writer.Flush();
writer.Close();

Python

#writeFile.py

writer = open("C:/data/newFile.txt", "w")
writer.write("line_1 \n");
writer.write("line_2 \n");
writer.write("line_3 \n");
writer.close();

Perl

#writeFile.pm

open newFile, ">C:/data/newFile.txt";
print newFile "line 1 \n";
print newFile "line 2 \n";
print newFile "line 3 \n";
close newFile;

Ruby

#writeFile.rb
writer = File.new("C:/data/newFile.txt", "w")
writer.print("line_1 \n");
writer.print("line_2 \n");
writer.print("line_3 \n");
writer.close();

Matlab

%writeCSV.M
mat = [1.0 1.1 1.2; 1.3 1.4 1.5]
dlmwrite('./data/test.csv', mat)

R

#writeCSV.R
v1=c(1.0, 1.1, 1.2)
v2=c(1.3, 1.4, 1.5)
df = data.frame(col1=v1, col2=v2)
write.csv(df, "C:/data/newFile.csv")

Julia

#writeFile.jl
a = Int64[]
push!(a,1)
append!(a,[2,3])
b = ["a", "b", "c"]
c = Array[]
push!(c,a)
push!(c,b)

file = open("C:/data/test.csv", "w")
for zeile in c

for element in zeile

write(file, "$element")
if element!=zeile[end]

write(file,",")

end

end
write(file, "\r\n")

end

close(file)

SPSS

*writeCSV.sps;

DATA LIST
/one 1-5 (A) two 6-10.

BEGIN DATA
line1 0.01
line2 0.02
line3 0.03
END DATA.


SAVE TRANSLATE OUTFILE='C:\data\test.csv'
/TYPE=CSV
/CELLS=VALUES.

SAS

*writeCSV.sas;

data test;

input one $ two;
cards;
line1 0.01
line2 0.02
line3 0.03
line4 0.04

run;

proc export data=test outfile="C:\data\newFile.csv" dbms=csv replace;
run;

Java

//readFile.java

try {

java.io.BufferedReader reader = new java.io.BufferedReader(new java.io.FileReader("C:/data/newFile.txt"));
String line = reader.readLine();

while(line != null) {

System.out.println(line);
line = reader.readLine();

}
reader.close();

} catch(java.io.IOException e) {

e.printStackTrace();

}

Scala

//readFile.scala

val textfile = Source.fromFile("C:/data/newFile.txt")
for(line <- textfile.getLines) {

println(line.toUpperCase)

} textfile.close

C#

//readFile.cs
using System.IO;

System.IO.TextReader reader = new System.IO.StreamReader("C:/data/newFile.txt");
String line = reader.ReadLine();
while(line != null) {

Console.WriteLine(line);
line = reader.ReadLine();

}
reader.Close();

Python

#readFile.py

reader = open("C:/data/newFile.txt", "r")
for line in reader:

print line.strip()

reader.close()

Perl

#readFile.pm

open newFile, "< C:/data/newFile.txt";
while () {

print $_;

}
close newFile;

Ruby

#readFile.rb
reader = File.new("C:/data/newFile.txt", "r")
reader.each_line {|line| print line}
reader.close()

Matlab

%readCSV.M
mat = dlmread('./data/test.csv')

R

#readCSV.R
df<-read.csv("C:/data/newFile.csv")

Julia

file = open(readall, "C:/data/test.csv")

lines = split(file, "\n")
for line in lines

elements = split(line, ",")
for element in elements

print(element)

end

end

SPSS

*readCSV.sps;

GET DATA
/TYPE = TXT
/DELIMITERS = ","
/FILE = 'C:\data\test.csv'
/VARIABLES = one A5 two F5.2 .

DATASET NAME DataSet1 WINDOW=FRONT.

SAS

*readCSV.sas;
proc import datafile="C:\data\newFile.csv" out=test dbms=csv replace;
getnames=yes;
run;

Java

//containers.java

int[] array = new int[2];
array[0] = 1;

double[][] matrix = new double[2][2];
matrix[0][0] = 1.0;

java.util.ArrayList< String > arrayList = new java.util.ArrayList< String >();
arrayList.add("element_1");
String element = arrayList.get(0);

java.util.TreeMap< Integer, String > treeMap = new java.util.TreeMap< Integer, String >();
treeMap.put(0,"element_0");
Integer firstKey = treeMap.firstKey();
String value = treeMap.get(firstKey);

Scala

//containers.scala

val liste01 = List("red", "green", "blue", "yellow")
println(liste01)
println(liste01(0))
val liste02 = liste01 :+ "black"
println(liste02)
val liste03 = liste02.sorted
println(liste03)
val liste04 = liste03 map (_.toUpperCase)
println(liste04)

val mappe = Map("blau" -> "blue", "rot" -> "red", "green" -> "grün")
for( (k, v) <- mappe) {

println("ger: "+k+" eng: "+v)

}

C#

//containers.cs
int[] array = new int[2];
array[0] = 1;

double[,] matrix = new double[2,2];
matrix[0,0] = 1.0;

List list = new List< String >();
list.Add("element_1");
String element = list[0];

Dictionary< int, String > dictionary = new Dictionary< int, String >();
dictionary[0] = "element_0";
Integer firstKey = dictionary.Keys.First();
String value = dictionary[firstKey];

Python

Perl

#containers.pm
@array = ("a", "b", 3, 4);

foreach (@array) {

print "$_\n";

}

print "$array[2]\n";



%hash = ("key1" => "element1", "key2" => 2);

foreach $key (sort keys %hash) {

$value = $hash{$key};
print "$key => $value\n";

}

Ruby

#containers.rb
array = ["a", "b", 3, 4];
array.each { | value | puts "value: #{value} \n" };

hash = {"key1" => "element1", "key2" => 2};
hash.each_pair {|key, value| puts "key: #{key} value: #{value} \n"};

Matlab

%containers.M
str = 'hello world'
value = 3.1416
matrix = [1.0 1.1 1.2; 1.3 1.4 1.5]
struc.key1 = str
struc.key2 = value
struc.key3 = matrix

R

#containers.R
numericVector <- c(1.0, 2.0, 3, 4)

alphaNumericVector <- c("one", "two", "three", "two")

multiDimArray <- array(numericVector, c(2,2,3,3))

aMatrix <- matrix(numericVector, c(2,2))

aFactor <- factor(alphaNumericVector)

aList <- list(first=numericVector, second=alphaNumericVector, third=aMatrix, fourth="fourth", fifth=5)

aDataFrame <- data.frame(a=numericVector[0:2], b=alphaNumericVector, c=aFactor)

Julia

#containers.jl
a = String[]
push!(a, "a")

b = Float64[]
push!(b, 2.5)

c = Dict{Int64, String}()
c[1] = "a"

SPSS

*containers.sps;

NEW FILE.

INPUT PROGRAM.

VECTOR vec(3).
COMPUTE vec(1) = 1.
COMPUTE vec(2) = 2.
COMPUTE vec(3) = 3.

END FILE.

END INPUT PROGRAM.

EXECUTE.

LIST.

SAS

*containers.sas;

data test;

input one $ two;
cards;
line1 0.01
line2 0.02
line3 0.03
line4 0.04

run;

data test1;

set test;
array a two;
do count = 1 to dim(a);

three = 3 * a{count};

end;
drop count;

run;

Java

//forLoop.java
for(int i=0; i<10; i++) {

System.out.println("line_"+i);

}


java.util.ArrayList< String > arrayList = new java.util.ArrayList< String >();
arrayList.add("element_1");
arrayList.add("element_2");

for(String element : arrayList) {

System.out.println(element);

}

Scala

//forLoop.scala
for(i <- 1 to 10) {

i match {

case 1 | 3 | 5 | 7 | 9 => println(i + " is an odd number")
case 2 | 4 | 6 | 8 | 10 => println(i + " is an even number")

}

}

C#

//forLoop.cs for (int i = 0; i < 10; i++)
{

Console.WriteLine("line_" + i);

}

List< String > list = new List< String >();
list.Add("element_1");
list.Add("element_2");

foreach (String element in list)
{

Console.WriteLine(element);

}

Python

#forLoop.py

list = []
list.append("element_1")
list.append("element_2")

for i in range(len(list)):

print "position "+str(i)+": "+list[i]

for element in list:

print element

Perl

#forLoop.pm

foreach (0...4) {

print "numer is: $_\n";

}

Ruby

#forLoop.rb
array = ["a", "b", 3, 4];
array.each {|element| puts element}

Matlab

%forLoop.M
for i = 0:10

i*2

end

R

#forLoop.R
for(i in seq(10)) {

print(i)

}

Juli

#forLoop.jl
a = [1,2,3,4,8]
for element in a

print("$element \n")

end

SPSS

*forLoop.sps;

NEW FILE.

INPUT PROGRAM.

LOOP i = 1 to 10.
COMPUTE x = x + RV.NORMAL(0,1).
LEAVE i.
LEAVE x.
END CASE.
END LOOP.

END FILE.

END INPUT PROGRAM.

EXECUTE.

DATASET NAME werte.

SORT CASES x.

SAVE OUTFILE = "C:\data\test.sav".

SAS

*forLoop.sas;

data test;

do i=0 to 10;

output;

end;

run;

data test1;

set test;
array a i;
do count = 1 to dim(a);

b = 3*a{count};

end;
drop count;

run;

Java

//ooConcepts.java
public class ClassOne {

public void methodOne() {

System.out.println("I am method one from class one");

}

}

public interface InterfaceOne {

public void methodTwo();

}

public class ClassTwo extends ClassOne implements InterfaceOne {

public void methodOne() {

System.out.println("I am method one from class two");

}

public void methodTwo() {

System.out.println("I am method two from class two");

}

}

ClassOne one = new ClassOne();
one.methodOne();

ClassTwo two = new ClassTwo();
two.methodOne();
two.methodTwo();

Scala

//ooConcepts.scala
// Scala being a functional language takes
// Types and Traits much more serious than classes
object scalaClass {

def scalaMethod() {

println("I am a method")

}

def main(args: Array[String]) = {

scalaMethod()

}

}

C#

//ooConcepts.cs
public class ClassOne
{

public void methodOne()
{

Console.WriteLine("I am method one from class one");

}

}

interface InterfaceOne {

void methodTwo();

}

public class ClassTwo : ClassOne, InterfaceOne {

public void methodOne() {

Console.WriteLine("I am method one from class two");

}

public void methodTwo()
{

Console.WriteLine("I am method two from class two");

}

}


ClassOne one = new ClassOne();
one.methodOne();

ClassTwo two = new ClassTwo();
two.methodOne();
two.methodTwo();

Python

#ooConcepts.py

class classOne:

def methodOne(self):

print "I am method one from class one"

class classTwo (one):

def methodTwo(self, comment):

print "I am method two from class two"
print comment

c2 = classTwo()
c2.methodOne()
c2.methodTwo("I am a comment")

Perl

#ooConcepts.pm

sub mult {

my $a = @_[0];
my $b = @_[1];
my $c = $a * $b;

}

$one = 4;
$two = 5;
$three = &mult($one, $two);
print "value: $three";

Ruby

#ooConcepts.rb

class ClassOne

def methodOne

puts "I am method one from class one";

end

end;


class ClassTwo < ClassOne

def methodTwo(comment)

@localComment = comment;
puts "I am method two from class two";
puts @localComment

end

end;


c1 = ClassOne.new;
c1.methodOne;

c2 = ClassTwo.new;
c2.methodOne;
c2.methodTwo("I am a comment");

Matlab

%ooConcepts.M
function r = ooConcepts(a, b)

r = a + 2*b

result = ooConcepts(4,5)

R

#ooConcepts.R
#run a script: source("scriptName")
#clear workspace: rm(list=ls())

sum <- function(vector) {

s <- 0
for(i in seq(along = vector)) {

s <- s + vector[i]

}

return(s)
}
a<-sum(c(1,2,3,4))
print(a)

Juli

#ooConcepts.jl
#to run a script:
#julia> include("C:/script.jl")

#simple function

function f1(a, b)

c = 0
for i in 1:a

c += b

end
c

end

print(f1(10,3))
print("\n")


#first class function

function createPower(x)

power = function (y)

return y^x

end
return power

end

square = createPower(2)
print(string("4^2: ", square(4), "\n"))
cube = createPower(3)
print(string("4^3: ", cube(4)), "\n")


#type

abstract Bicycle

type Roadbike <: Bicycle

number_of_gears::Int64

end

myBike = Roadbike(24)

SPSS

*ooConcepts.sps;

DEFINE !macro1(a=!CHAREND(',') /b=!CMDEND).
COMPUTE var1 = !a + !b.
END CASE.
!ENDDEFINE.

DEFINE !macro2(a=!TOKENS(1)).

!DO !i = 1 !TO !a.
COMPUTE var2 = !i+5.
END CASE.
!DOEND.


!ENDDEFINE.


NEW FILE.
INPUT PROGRAM.


!macro1 a=4,b=5.
!macro2 a=4.

END FILE.
END INPUT PROGRAM.
EXECUTE.

SAS

*ooConcepts.sas;

%macro mult(a, b);

data results;

c = &a * &b;

run;

%mend;


%macro loop(a);

%do i = 1 %to &a;

%put &i;

%end;

%mend;


data test;

%mult(4,5);
%loop(3);

run;

Java

//database.java
//using SQLiteJDBC

try {

Class.forName("org.sqlite.JDBC");

} catch (ClassNotFoundException e) {

e.printStackTrace();

}

try {

java.sql.Connection conn = java.sql.DriverManager.getConnection("jdbc:sqlite:test.db");
java.sql.Statement stat = conn.createStatement();
stat.executeUpdate("drop table if exists people;");
stat.executeUpdate("create table people (name, year_of_birth);");

java.sql.PreparedStatement prepStat = conn.prepareStatement("insert into people values (?,?);");
prepStat.setString(1,"Goethe");
prepStat.setInt(2, 1749);
prepStat.addBatch();
prepStat.setString(1,"Schiller");
prepStat.setInt(2, 1759);
prepStat.addBatch();
prepStat.setString(1,"Napoleon");
prepStat.setInt(2, 1769);
prepStat.addBatch();

conn.setAutoCommit(false);
prepStat.executeBatch();
conn.setAutoCommit(true);

java.sql.ResultSet rs = stat.executeQuery("select * from people;");
while (rs.next()) {

System.out.println("name = " + rs.getString("name"));
System.out.println("year of birth = " + rs.getInt("year_of_birth"));

}
rs.close();
conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

Scala

C#

//database.cs
//using MS-ACCESS

private System.Data.DataTable doQuery(String dbFileName, String sql)
{

System.Data.Common.DbProviderFactory factory = System.Data.Common.DbProviderFactories.GetFactory("System.Data.OleDb");

System.Data.Common.DbConnection connection = factory.CreateConnection();
connection.ConnectionString = getMSAccessConnectionString(dbFileName);

System.Data.Common.DbCommand command = factory.CreateCommand();
command.CommandText = sql;
command.Connection = connection;

System.Data.Common.DbDataAdapter adapter = factory.CreateDataAdapter();
adapter.SelectCommand = command;
System.Data.DataSet dataset = new System.Data.DataSet();
adapter.Fill(dataset);

return dataset.Tables[0];

}


private void doUpdate(String dbFileName, String sql)
{

System.Data.Common.DbProviderFactory factory = System.Data.Common.DbProviderFactories.GetFactory("System.Data.OleDb");

System.Data.Common.DbConnection connection = factory.CreateConnection();
connection.ConnectionString = getMSAccessConnectionString(dbFileName);

System.Data.Common.DbCommand command = factory.CreateCommand();
command.CommandText = sql;
command.Connection = connection;

connection.Open();
command.ExecuteNonQuery();
connection.Close();

}


private String getMSAccessConnectionString(String fileName)
{

String connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + ";Jet OLEDB:Engine Type=5";
return connectionString;

}



String sqlCreate = "CREATE TABLE people (name text, year_of_birth int)";
doUpdate("C:/data/test.mdb", sqlCreate);
String sqlGoethe = "INSERT INTO people (name, year_of_birth) VALUES ('Goethe', 1749)";
doUpdate("C:/data/test.mdb", sqlGoethe);
String sqlSchiller = "INSERT INTO people (name, year_of_birth) VALUES ('Schiller', 1759)";
doUpdate("C:/data/test.mdb", sqlSchiller);
String sqlNapoleon = "INSERT INTO people (name, year_of_birth) VALUES ('Napoleon', 1769)";
doUpdate("C:/data/test.mdb", sqlNapoleon);

String sqlQuery = "SELECT * FROM people";
System.Data.DataTable table = doQuery("C:/data/test.mdb", sqlQuery);
foreach (System.Data.DataRow row in table.Rows)
{

String name = (String)row[0];
int yearOfBirth = (int)row[1];
Console.WriteLine("name: " + name + " year of birth: " + yearOfBirth);

}

Python

#database.py
#using pysqlite

from pysqlite2 import dbapi2 as sqlite

con = sqlite.connect("mydb")
cursor = con.cursor()
cursor.execute("create table people (name varchar(20),year_of_birth integer);")
cursor.execute("insert into people (name, year_of_birth) values ('Goethe', 1749);")
cursor.execute("insert into people (name, year_of_birth) values ('Schiller', 1759);")
cursor.execute("insert into people (name, year_of_birth) values ('Napoleon', 1769);")
con.commit()

SELECT = "select * from people"
cursor.execute(SELECT)
print cursor.fetchall()

cursor.execute(SELECT)
for row in cursor:

print "name: ", row[0], " year of birth: ", row[1]

Perl

#database.pm
#using DBD_SQLite

use DBI;
$sql1 = "drop table if exists people";
$sql2 = "create table people (name, year_of_birth)";
$sql3 = "insert into people values ('Goethe', 1749)";
$sql4 = "insert into people values ('Schiller', 1759)";
$sql5 = "insert into people values ('Napoleon', 1769)";
@sqls = ($sql1, $sql2, $sql3, $sql4, $sql5);

$dbh = DBI->connect( "dbi:SQLite:dbname=TEST_DB", "", "" );

foreach(@sqls) {

$sth_in = $dbh->prepare($_);
$sth_in->execute();

} $sth_in-> finish();


$sql_read = "select name, year_of_birth from people";

$sth_out = $dbh->prepare($sql_read);
$sth_out->execute();
$sth_out->bind_columns( \$name, \$year_of_birth );

while ( $sth_out->fetch() ) {

print "name $name, year $year_of_birth \n";

}

$sth_out->finish();

$dbh->disconnect();

R

#database.R
names <- c("Schiller", "Goethe", "Napoleon")
years <- c(1749, 1759, 1769)
f1 <- data.frame(names=names, years=years)
library("RSQLite")
con <- dbConnect(dbDriver("SQLite"), dbname="mydb")
#dbSendQuery(con, "drop table years_of_birth")
dbWriteTable(con, "years_of_birth", f1)

t <- dbListTables(con)
rs <- dbSendQuery(con, "select * from years_of_birth")
f2 <- fetch(rs)
dbClearResult(rs)
dbDisconnect(con)

Julia

#database.jl
using ODBC

ODBC.connect("SPSSDATA", usr="db2admin", pwd="db2admin")

dataFrame = query("select * from BETRUG")

disconnect()

SPSS

*database.sps;
GET DATA
/TYPE=ODBC
/CONNECT='DSN=SPSSDATA;UID db2admin;PWD db2admin;DBALIAS=SPSSDATA;'
/SQL='SELECT "X1", "X2", "X3" FROM "DB2ADMIN"."CLUSTERING"'
/ASSUMEDSTRWIDTH=255
/UNENCRYPTED.

CACHE.
EXECUTE.
DATASET NAME DataSet1 WINDOW=FRONT.

SAS

*database.sas;
*using sqlite and sqliteodbc.exe;
*datasource=sqliteDataSource;
*database=c:/data/sqliteDataBase.db3;

libname datBase odbc dsn=sqliteDataSource;

proc sql;
create table datBase.people (name varchar(20),year_of_birth integer);
quit;

proc sql;
insert into datBase.people (name, year_of_birth) values ('Goethe', 1749);
quit;

proc sql;
insert into datBase.people (name, year_of_birth) values ('Schiller', 1759);
quit;

proc sql;
insert into datBase.people (name, year_of_birth) values ('Napoleon', 1769);
quit;

proc sql;
create table test as select * from datBase.people;
quit;

Java

//random.java
int n = 10;
int k = 3;
double[][] x = new double[n][k];
java.util.Random rand = new java.util.Random();
for (int i = 0; i < n; i++) {

for (int j = 0; j < k; j++) {

x[i][j] = rand.nextGaussian();

}

}

Scala

//random.scala
//using Breeze
import breeze.linalg._
val norm = breeze.stats.distributions.Gaussian(0,1)
val werte = norm.sample(20)
print(werte)

C#

//random.cs
int n = 10;
int k = 3;
double[,] x = new double[n,k];
Random rand = new Random();
for (int i = 0; i < n; i++) {

for (int j = 0; j < k; j++) {

x[i,j] = rand.NextDouble();

}

}

Python

#random.py
import numpy

mu = 0
sig = 1
n = 10

x = numpy.random.normal(mu, sig, n)
y = numpy.ones(n) + 0.5 * x + numpy.random.normal(0, 1, n)
print y

Perl

#random.pm
use Math::Random;

$mu = 0;
$sig = 1;
$value = random_normal($mu, $sig);
print "value $value";

Ruby

#random.rb
n = 8 k = 3 x = Array.new() x.fill(0...n){|y| y=Array.new(); y.fill(0...k) {|z| z=rand()}}

Matlab

%random.M
mu =0 sig=1
n=10
k=1

vals = random('norm', mu, sig, n, k)

R

#random.R
n<- 10
x <- 100 * rnorm(n)
u <- rnorm(n)
y <- rep(0,n)
for(i in 1:n)

y[i] = 1 + 0.5*x[i] + u[i]

Julia

#random.jl
using Distributions

logNorm = LogNormal()

values = rand(logNorm, 100)

skewness(values)
kurtosis(values)

SPSS

*random.sps;

NEW FILE.

INPUT PROGRAM.

LOOP i = 1 to 10.
COMPUTE x1 = RV.NORMAL(0,1).
COMPUTE x2 = RV.UNIFORM(0.0, 1.0).
COMPUTE x3 = RV.POISSON(0.5).
END CASE.
END LOOP.

END FILE.

END INPUT PROGRAM.

EXECUTE.

DATASET NAME werte.

SAVE OUTFILE = "C:\data\test.sav".

SAS

*random.sas;
data test;

do i=0 to 500;

x = normal(-1);
x1 = rannor(123);
y = uniform(-1);
y1 = ranuni(123);
output;

end;

run;

Java

//matrix.java
//using JAMA: Java Matrix Package

int n = 10;
int k = 3;
double[][] x = new double[n][k];
java.util.Random rand = new java.util.Random();
for (int i = 0; i < n; i++) {

for (int j = 0; j < k; j++) {

x[i][j] = rand.nextGaussian();

}

}

Jama.Matrix X = new Jama.Matrix(x);
Jama.Matrix XtX = X.transpose().times(X);
Jama.Matrix XtXi = XtX.inverse();
for(int i=0; i< XtXi.getRowDimension(); i++) {

for(int j=0; j< XtXi.getColumnDimension(); j++) {

System.out.print(" "+XtXi.get(i,j));

}
System.out.println("");

}

Scala