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MATLAB R2013a screenshot  
Developer(s)  MathWorks 

Stable release  2013a 
Preview release  None [±] 
Written in  C, C++, Java 
Operating system  Crossplatform^{[1]} 
Type  Technical computing 
License  Proprietary 
Website  MATLAB product page 
MATLAB R2013a screenshot  
Developer(s)  MathWorks 

Stable release  2013a 
Preview release  None [±] 
Written in  C, C++, Java 
Operating system  Crossplatform^{[1]} 
Type  Technical computing 
License  Proprietary 
Website  MATLAB product page 
Paradigm(s)  multiparadigm: imperative, procedural, objectoriented, array 

Appeared in  late 1970s 
Designed by  Cleve Moler 
Developer  MathWorks 
Typing discipline  dynamic, weak 
OS  Crossplatform 
Usual filename extensions  .m 

MATLAB (matrix laboratory) is a numerical computing environment and fourthgeneration programming language. Developed by MathWorks, MATLAB allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces, and interfacing with programs written in other languages, including C, C++, Java, and Fortran.
Although MATLAB is intended primarily for numerical computing, an optional toolbox uses the MuPAD symbolic engine, allowing access to symbolic computing capabilities. An additional package, Simulink, adds graphical multidomain simulation and ModelBased Design for dynamic and embedded systems.
In 2004, MATLAB had around one million users across industry and academia.^{[2]} MATLAB users come from various backgrounds of engineering, science, and economics. MATLAB is widely used in academic and research institutions as well as industrial enterprises.
Cleve Moler, the chairman of the computer science department at the University of New Mexico, started developing MATLAB in the late 1970s.^{[3]} He designed it to give his students access to LINPACK and EISPACK without them having to learn Fortran. It soon spread to other universities and found a strong audience within the applied mathematics community. Jack Little, an engineer, was exposed to it during a visit Moler made to Stanford University in 1983. Recognizing its commercial potential, he joined with Moler and Steve Bangert. They rewrote MATLAB in C and founded MathWorks in 1984 to continue its development. These rewritten libraries were known as JACKPAC.^{[4]} In 2000, MATLAB was rewritten to use a newer set of libraries for matrix manipulation, LAPACK.^{[5]}
MATLAB was first adopted by researchers and practitioners in control engineering, Little's specialty, but quickly spread to many other domains. It is now also used in education, in particular the teaching of linear algebra and numerical analysis, and is popular amongst scientists involved in image processing.^{[3]}
The MATLAB application is built around the MATLAB language, and most use of MATLAB involves typing MATLAB code into the Command Window (as an interactive mathematical shell), or executing text files containing MATLAB codes, including scripts and/or functions.^{[6]}
Variables are defined using the assignment operator, =
. MATLAB is a weakly typed programming language because types are implicitly converted.^{[7]} It is a dynamically typed language because variables can be assigned without declaring their type, except if they are to be treated as symbolic objects,^{[8]} and that their type can change. Values can come from constants, from computation involving values of other variables, or from the output of a function. For example:
>> x = 17 x = 17 >> x = 'hat' x = hat >> y = x + 0 y = 104 97 116 >> x = [3*4, pi/2] x = 12.0000 1.5708 >> y = 3*sin(x) y = 1.6097 3.0000
A simple array is defined using the colon syntax: init:
increment:
terminator. For instance:
>> array = 1:2:9 array = 1 3 5 7 9
defines a variable named array
(or assigns a new value to an existing variable with the name array
) which is an array consisting of the values 1, 3, 5, 7, and 9. That is, the array starts at 1 (the init value), increments with each step from the previous value by 2 (the increment value), and stops once it reaches (or to avoid exceeding) 9 (the terminator value).
>> array = 1:3:9 array = 1 4 7
the increment value can actually be left out of this syntax (along with one of the colons), to use a default value of 1.
>> ari = 1:5 ari = 1 2 3 4 5
assigns to the variable named ari
an array with the values 1, 2, 3, 4, and 5, since the default value of 1 is used as the incrementer.
Indexing is onebased,^{[9]} which is the usual convention for matrices in mathematics, although not for some programming languages such as C, C++, and Java.
Matrices can be defined by separating the elements of a row with blank space or comma and using a semicolon to terminate each row. The list of elements should be surrounded by square brackets: []. Parentheses: () are used to access elements and subarrays (they are also used to denote a function argument list).
>> A = [16 3 2 13; 5 10 11 8; 9 6 7 12; 4 15 14 1] A = 16 3 2 13 5 10 11 8 9 6 7 12 4 15 14 1 >> A(2,3) ans = 11
Sets of indices can be specified by expressions such as "2:4", which evaluates to [2, 3, 4]. For example, a submatrix taken from rows 2 through 4 and columns 3 through 4 can be written as:
>> A(2:4,3:4) ans = 11 8 7 12 14 1
A square identity matrix of size n can be generated using the function eye, and matrices of any size with zeros or ones can be generated with the functions zeros and ones, respectively.
>> eye(3) ans = 1 0 0 0 1 0 0 0 1 >> zeros(2,3) ans = 0 0 0 0 0 0 >> ones(2,3) ans = 1 1 1 1 1 1
Most MATLAB functions can accept matrices and will apply themselves to each element. For example, mod(2*J,n)
will multiply every element in "J" by 2, and then reduce each element modulo "n". MATLAB does include standard "for" and "while" loops, but (as in other similar applications such as R), using the vectorized notation often produces code that is faster to execute. This code, excerpted from the function magic.m, creates a magic square M for odd values of n (MATLAB function meshgrid is used here to generate square matrices I and J containing 1:n).
[J,I] = meshgrid(1:n); A = mod(I + J  (n + 3) / 2, n); B = mod(I + 2 * J  2, n); M = n * A + B + 1;
MATLAB has structure data types.^{[10]} Since all variables in MATLAB are arrays, a more adequate name is "structure array", where each element of the array has the same field names. In addition, MATLAB supports dynamic field names^{[11]} (field lookups by name, field manipulations, etc.). Unfortunately, MATLAB JIT does not support MATLAB structures, therefore just a simple bundling of various variables into a structure will come at a cost.^{[citation needed]}
MATLAB supports elements of lambda calculus by introducing function handles,^{[12]} or function references, which are implemented either in .m files or anonymous^{[13]}/nested functions.^{[14]}
Although MATLAB has classes, the syntax and calling conventions are significantly different from other languages. MATLAB has value classes and reference classes, depending on whether the class has handle as a superclass (for reference classes) or not (for value classes).^{[15]}
Method call behavior is different between value and reference classes. For example, a call to a method
object.method();
can alter any member of object only if object is an instance of a reference class.
MATLAB supports developing applications with graphical user interface features. MATLAB includes GUIDE^{[16]} (GUI development environment) for graphically designing GUIs.^{[17]} It also has tightly integrated graphplotting features. For example the function plot can be used to produce a graph from two vectors x and y. The code:
x = 0:pi/100:2*pi; y = sin(x); plot(x,y)
produces the following figure of the sine function:
A MATLAB program can produce threedimensional graphics using the functions surf, plot3 or mesh.
[X,Y] = meshgrid(10:0.25:10,10:0.25:10); f = sinc(sqrt((X/pi).^2+(Y/pi).^2)); mesh(X,Y,f); axis([10 10 10 10 0.3 1]) xlabel('{\bfx}') ylabel('{\bfy}') zlabel('{\bfsinc} ({\bfR})') hidden off  [X,Y] = meshgrid(10:0.25:10,10:0.25:10); f = sinc(sqrt((X/pi).^2+(Y/pi).^2)); surf(X,Y,f); axis([10 10 10 10 0.3 1]) xlabel('{\bfx}') ylabel('{\bfy}') zlabel('{\bfsinc} ({\bfR})')  
This code produces a wireframe 3D plot of the twodimensional unnormalized sinc function:  This code produces a surface 3D plot of the twodimensional unnormalized sinc function:  
In MATLAB, graphical user interfaces can be programmed with the GUI design environment (GUIDE) tool.^{[18]}
MATLAB's support for objectoriented programming includes classes, inheritance, virtual dispatch, packages, passbyvalue semantics, and passbyreference semantics.^{[19]}
classdef hello methods function doit(this) disp('Hello!') end end end
When put into a file named hello.m, this can be executed with the following commands:
>> x = hello; >> x.doit; Hello!
MATLAB can call functions and subroutines written in the C programming language or Fortran.^{[20]} A wrapper function is created allowing MATLAB data types to be passed and returned. The dynamically loadable object files created by compiling such functions are termed "MEXfiles" (for MATLAB executable).^{[21]}^{[22]}
Libraries written in Perl, Java, ActiveX or .NET can be directly called from MATLAB,^{[23]}^{[24]} and many MATLAB libraries (for example XML or SQL support) are implemented as wrappers around Java or ActiveX libraries. Calling MATLAB from Java is more complicated, but can be done with a MATLAB toolbox^{[25]} which is sold separately by MathWorks, or using an undocumented mechanism called JMI (JavatoMATLAB Interface),^{[26]}^{[27]} (which should not be confused with the unrelated Java Metadata Interface that is also called JMI).
As alternatives to the MuPAD based Symbolic Math Toolbox available from MathWorks, MATLAB can be connected to Maple or Mathematica.^{[28]}^{[29]}
Libraries also exist to import and export MathML.^{[30]}
MATLAB is a proprietary product of MathWorks, so users are subject to vendor lockin.^{[2]}^{[31]} Although MATLAB Builder product can deploy MATLAB functions as library files which can be used with .NET^{[32]} or Java^{[33]} application building environment, future development will still be tied to the MATLAB language.
Each toolbox is purchased separately. If an evaluation license is requested, the MathWorks sales department requires detailed information about the project for which MATLAB is to be evaluated. Overall the process of acquiring a license is expensive in terms of money and time^{[citation needed]}. If granted (which it often is), the evaluation license is valid for two to four weeks. A student version of MATLAB is also available.
It has been reported that EU competition regulators are investigating whether MathWorks refused to sell licenses to a competitor.^{[34]}
MATLAB has a number of competitors.^{[35]} Commercial competitors include Mathematica, Maple, and IDL. There are also free open source alternatives to MATLAB, in particular GNU Octave, Scilab, FreeMat, Julia, and Sage which are intended to be mostly compatible with the MATLAB language. Among other languages that treat arrays as basic entities (array programming languages) are APL, Fortran 90 and higher, SLang, as well as the statistical languages R and S. There are also libraries to add similar functionality to existing languages, such as IT++ for C++, Perl Data Language for Perl, ILNumerics for .NET, NumPy/SciPy for Python, and Numeric.js for JavaScript.
GNU Octave stands out as it treats incompatibility with MATLAB as a bug (see GNU Octave#Matlab), therefore it aims to provide a software clone.
Version^{[36]}  Release name  Number  Bundled JVM  Year  Release Date  Notes 

MATLAB 1.0  1984  
MATLAB 2  1986  
MATLAB 3  1987  
MATLAB 3.5  1990  Ran on MSDOS but required at least a 386 processor. Version 3.5m required math coprocessor  
MATLAB 4  1992  
MATLAB 4.2c  1994  Ran on Windows 3.1. Required a math coprocessor  
MATLAB 5.0  Volume 8  1996  December, 1996  Unified releases across all platforms.  
MATLAB 5.1  Volume 9  1997  May, 1997  
MATLAB 5.1.1  R9.1  
MATLAB 5.2  R10  1998  March, 1998  
MATLAB 5.2.1  R10.1  
MATLAB 5.3  R11  1999  January, 1999  
MATLAB 5.3.1  R11.1  November, 1999  
MATLAB 6.0  R12  12  1.1.8  2000  November, 2000  First release with bundled Java Virtual Machine (JVM). 
MATLAB 6.1  R12.1  1.3.0  2001  June, 2001  
MATLAB 6.5  R13  13  1.3.1  2002  July, 2002  
MATLAB 6.5.1  R13SP1  2003  
MATLAB 6.5.2  R13SP2  
MATLAB 7  R14  14  1.4.2  2004  June, 2004  
MATLAB 7.0.1  R14SP1  October, 2004  
MATLAB 7.0.4  R14SP2  1.5.0  2005  March 7, 2005  Support for memorymapped files.^{[37]}  
MATLAB 7.1  R14SP3  1.5.0  September 1, 2005  
MATLAB 7.2  R2006a  15  1.5.0  2006  March 1, 2006  
MATLAB 7.3  R2006b  16  1.5.0  September 1, 2006  HDF5based MATfile support  
MATLAB 7.4  R2007a  17  1.5.0_07  2007  March 1, 2007  New bsxfun function to apply elementbyelement binary operation with singleton expansion enabled.^{[38]} 
MATLAB 7.5  R2007b  18  1.6.0  September 1, 2007  Last release for Windows 2000 and PowerPC Mac. License Server support for Windows Vista.^{[39]} New internal format for Pcode.  
MATLAB 7.6  R2008a  19  1.6.0  2008  March 1, 2008  Major enhancements to objectoriented programming capabilities with a new class definition syntax,^{[40]} and ability to manage namespaces with packages.^{[41]} 
MATLAB 7.7  R2008b  20  1.6.0_04  October 9, 2008  New Map data structure.^{[42]} Upgrades to random number generators.^{[43]}  
MATLAB 7.8  R2009a  21  1.6.0_04  2009  March 6, 2009  First release for 32bit & 64bit Microsoft Windows 7. New external interface to Microsoft .NET Framework.^{[44]} 
MATLAB 7.9  R2009b  22  1.6.0_12  September 4, 2009  First release for Intel 64bit Mac, and last for Solaris SPARC. New usage for the tilde operator (~ ) to ignore arguments in function calls.^{[45]}^{[46]}  
MATLAB 7.9.1  R2009bSP1  1.6.0_12  2010  April 1, 2010  bug fixes.  
MATLAB 7.10  R2010a  23  1.6.0_12  March 5, 2010  Last release for Intel 32bit Mac.  
MATLAB 7.11  R2010b  24  1.6.0_17  September 3, 2010  Support for enumerations added.^{[47]}  
MATLAB 7.11.1  R2010bSP1  1.6.0_17  2011  March 17, 2011  bug fixes and updates.  
MATLAB 7.11.2  R2010bSP2  1.6.0_17  April 5, 2012^{[48]}  bug fixes.  
MATLAB 7.12  R2011a  25  1.6.0_17  April 8, 2011  New rng function to control random number generation.^{[49]}^{[50]}^{[51]}  
MATLAB 7.13  R2011b  26  1.6.0_17  September 1, 2011  Access/change parts of variables directly in MATfiles, without loading into memory.^{[52]}  
MATLAB 7.14  R2012a  27  1.6.0_17  2012  March 1, 2012  
MATLAB 8  R2012b  28  1.6.0_17  September 11, 2012  First release with Toolstrip interface.^{[53]} MATLAB Apps.^{[54]} Redesigned documentation system.  
MATLAB 8.1  R2013a  29  1.6.0_17  2013  March 7, 2013  New unit testing framework.^{[55]} 
MATLAB 8.2^{[56]}  R2013b  30  1.7.0_11  September 6, 2013  New table data type.^{[57]} 
The number (or Release number) is the version reported by Concurrent License Manager program FLEXlm.
For a complete list of changes of both MATLAB and official toolboxes, consult the MATLAB release notes.^{[58]}
Several easter eggs exist in MATLAB.^{[64]} These include hidden pictures,^{[65]} and random inside jokes. For example, typing in "spy" will generate a picture of the spies from Spy vs Spy. "Spy" was changed to an image of a dog in recent releases (R2011B). Typing in "why" randomly outputs a philosophical answer. Other commands include "penny", "toilet", "image", and "life". Not every Easter egg appears in every version of MATLAB – some appear and some disappear.
Wikibooks has a book on the topic of: MATLAB Programming 
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