Contents 1 History 2 Syntax 2.1 Variables 2.2 Vectors and matrices 2.3 Structures 2.4 Functions 2.5 Function handles 2.6 Classes and object-oriented programming 3 Graphics and graphical user interface programming 4 Interfacing with other languages 5 License 6 Alternatives 7 Release history 8 File extensions 8.1 MATLAB 8.2 Simulink 8.3 Simscape 8.4 MuPAD 8.5 Third-party 9 Easter eggs 10 See also 11 Notes 12 References 13 External links

History Cleve Moler, the chairman of the computer science department at the University of New Mexico, started developing MATLAB in the late 1970s.[8] 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.[9] In 2000, MATLAB was rewritten to use a newer set of libraries for matrix manipulation, LAPACK.[10] 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, numerical analysis, and is popular amongst scientists involved in image processing.[8]

Syntax The MATLAB application is built around the MATLAB scripting language. Common usage of the MATLAB application involves using the Command Window as an interactive mathematical shell or executing text files containing MATLAB code.[11] Variables Variables are defined using the assignment operator, =. MATLAB is a weakly typed programming language because types are implicitly converted.[12] It is an inferred typed language because variables can be assigned without declaring their type, except if they are to be treated as symbolic objects,[13] 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 Vectors and matrices A simple array is defined using the colon syntax: initial: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 initial 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 one-based,[14] 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(3,3) 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 Transposing a vector or a matrix is done either by the function transpose or by adding prime to the matrix. >> A = [1 ; 2], B = A', C = transpose(A) A = 1 2 B = 1 2 C = 1 2 >> D = [0 3 ; 1 5], D' D = 0 3 1 5 ans = 0 1 3 5 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; Structures MATLAB has structure data types.[15] 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[16] (field look-ups 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.[17] Functions When creating a MATLAB function, the name of the file should match the name of the first function in the file. Valid function names begin with an alphabetic character, and can contain letters, numbers, or underscores. Functions are also often case sensitive. [18] Function handles MATLAB supports elements of lambda calculus by introducing function handles,[19] or function references, which are implemented either in .m files or anonymous[20]/nested functions.[21] Classes and object-oriented programming MATLAB supports object-oriented programming including classes, inheritance, virtual dispatch, packages, pass-by-value semantics, and pass-by-reference semantics.[22] However, 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 super-class (for reference classes) or not (for value classes).[23] 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. An example of a simple class is provided below. classdef hello methods function greet(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.greet(); Hello!

Graphics and graphical user interface programming MATLAB supports developing applications with graphical user interface (GUI) features. MATLAB includes GUIDE[24] (GUI development environment) for graphically designing GUIs.[25] It also has tightly integrated graph-plotting 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 three-dimensional 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 two-dimensional unnormalized sinc function:     This code produces a surface 3D plot of the two-dimensional unnormalized sinc function:     In MATLAB, graphical user interfaces can be programmed with the GUI design environment (GUIDE) tool.[26]

Interfacing with other languages MATLAB can call functions and subroutines written in the programming languages C or Fortran.[27] 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 "MEX-files" (for MATLAB executable).[28][29] Since 2014 increasing two-way interfacing with Python is being added.[30][31] Libraries written in Perl, Java, ActiveX or .NET can be directly called from MATLAB,[32][33] 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[34] which is sold separately by MathWorks, or using an undocumented mechanism called JMI (Java-to-MATLAB Interface),[35][36] (which should not be confused with the unrelated Java Metadata Interface that is also called JMI). Official MATLAB API for Java was added in 2016.[37] As alternatives to the MuPAD based Symbolic Math Toolbox available from MathWorks, MATLAB can be connected to Maple or Mathematica.[38][39] Libraries also exist to import and export MathML.[40]

License MATLAB is a proprietary product of MathWorks, so users are subject to vendor lock-in.[7][41] Although MATLAB Builder products can deploy MATLAB functions as library files which can be used with .NET[42] or Java[43] 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. If granted (which it often is), the evaluation license is valid for two to four weeks. A student version of MATLAB is available as is a home-use license for MATLAB, Simulink, and a subset of Mathwork's Toolboxes at substantially reduced prices. It has been reported that European Union (EU) competition regulators are investigating whether MathWorks refused to sell licenses to a competitor.[44] The regulators dropped the investigation after the complainant withdrew their accusation and no evidence of wrongdoing was found.[45]

Alternatives See also: list of numerical analysis software and comparison of numerical analysis software MATLAB has a number of competitors.[46] Commercial competitors include Mathematica, TK Solver, Maple, and IDL. There are also free open source alternatives to MATLAB, in particular GNU Octave, Scilab, FreeMat, and SageMath, which are intended to be mostly compatible with the MATLAB language; the Julia programming language also initially used MATLAB-like syntax. Among other languages that treat arrays as basic entities (array programming languages) are APL, Fortran 90 and higher, S-Lang, 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/matplotlib for Python, SciLua/Torch for Lua, SciRuby for Ruby, and Numeric.js for JavaScript. GNU Octave is unique from other alternatives because it treats incompatibility with MATLAB as a bug (see MATLAB Compatibility of GNU Octave), therefore, making GNU Octave a superset of the MATLAB language.

Release history Version[47] 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 DOS but needed at least a 386 processor; version 3.5m needed math coprocessor MATLAB 4 1992 Ran on Macintosh MATLAB 4.2c 1994 Ran on Windows 3.1x, needed 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 Last version working on classic Mac's 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 Last release for IBM/AIX, Alpha/TRU64, and SGI/IRIX[48] MATLAB 7 R14 14 1.4.2 2004 June, 2004 Introduced anonymous and nested functions[49] Re-introduced for Mac (under Mac OS X) MATLAB 7.0.1 R14SP1 October, 2004 MATLAB 7.0.4 R14SP2 1.5.0 2005 March 7, 2005 Support for memory-mapped files[50] 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 HDF5-based MAT-file support MATLAB 7.4 R2007a 17 1.5.0_07 2007 March 1, 2007 New bsxfun function to apply element-by-element binary operation with singleton expansion enabled[51] 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;[52] new internal format for P-code MATLAB 7.6 R2008a 19 1.6.0 2008 March 1, 2008 Major enhancements to object-oriented programming abilities with a new class definition syntax,[53] and ability to manage namespaces with packages[54] MATLAB 7.7 R2008b 20 1.6.0_04 October 9, 2008 New Map data structure:[55] upgrades to random number generators[56] MATLAB 7.8 R2009a 21 1.6.0_04 2009 March 6, 2009 First release for Microsoft 32-bit & 64-bit Windows 7, new external interface to .NET Framework[57] MATLAB 7.9 R2009b 22 1.6.0_12 September 4, 2009 First release for Intel 64-bit Mac, and last for Solaris SPARC; new use for the tilde operator (~) to ignore arguments in function calls[58][59] 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 32-bit Mac MATLAB 7.11 R2010b 24 1.6.0_17 September 3, 2010 Add support for enumerations[60] 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[61] bug fixes MATLAB 7.12 R2011a 25 1.6.0_17 April 8, 2011 New rng function to control random number generation[62][63][64] MATLAB 7.13 R2011b 26 1.6.0_17 September 1, 2011 Access-change parts of variables directly in MAT-files, without loading into memory;[65] increased maximum local workers with Parallel Computing Toolbox from 8 to 12[66] 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;[67] MATLAB Apps.[68] redesigned documentation system MATLAB 8.1 R2013a 29 1.6.0_17 2013 March 7, 2013 New unit testing framework[69] MATLAB 8.2 R2013b 30 1.7.0_11 September 6, 2013[70] New table data type[71] MATLAB 8.3 R2014a 31 1.7.0_11 2014 March 7, 2014[72] Simplified compiler setup for building MEX-files; USB Webcams support in core MATLAB; number of local workers no longer limited to 12 with Parallel Computing Toolbox MATLAB 8.4 R2014b 32 1.7.0_11 October 3, 2014 New class-based graphics engine (a.k.a. HG2);[73] tabbing function in GUI;[74] improved user toolbox packaging and help files;[75] new objects for time-date manipulations;[76] Git-Subversion integration in IDE;[77] big data abilities with MapReduce (scalable to Hadoop);[78] new py package for using Python from inside MATLAB,[79] new engine interface to call MATLAB from Python;[80] several new and improved functions: webread (RESTful web services with JSON/XML support), tcpclient (socket-based connections), histcounts, histogram, animatedline, and others MATLAB 8.5 R2015a 33 1.7.0_60 2015 March 5, 2015 Last release supporting Windows XP and Windows Vista MATLAB 8.5 R2015aSP1 1.7.0_60 October 14, 2015 MATLAB 8.6 R2015b 34 1.7.0_60 September 3, 2015 New MATLAB execution engine (a.k.a. LXE);[81] graph and digraph classes to work with graphs and networks;[82] MinGW-w64 as supported compiler on Windows;[83] Last version with 32-bit support MATLAB 9.0 R2016a 35 1.7.0_60 2016 March 3, 2016 Live Scripts: interactive documents that combine text, code, and output (in the style of Literate programming);[84] App Designer: a new development environment for building apps (with new kind of UI figures, axes, and components);[85] pause execution of running programs using a Pause Button MATLAB 9.1 R2016b 36 1.7.0_60 September 15, 2016 define local functions in scripts;[86] automatic expansion of dimensions (previously provided via explicit call to bsxfun); tall arrays for Big data;[87] new string type;[88] new functions to encode/decode JSON;[89] official MATLAB Engine API for Java[37] MATLAB 9.2 R2017a 37 1.7.0_60 2017 March 9, 2017 MATLAB Online: cloud-based MATLAB desktop accessed in a web browser;[90] double-quoted strings; new memoize function for Memoization; expanded object properties validation;[91] mocking framework for unit testing;[92] MEX targets 64-bit by default; new heatmap function for creating heatmap charts[93] MATLAB 9.3 R2017b 38 1.8.0_121 September 2017 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.[94]

Easter eggs Several easter eggs exist in MATLAB.[108] These include hidden pictures,[109] and jokes. For example, typing in "spy" used to generate a picture of the spies from Spy vs Spy, but now displays an image of a dog. 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.

See also Comparison of numerical analysis software List of numerical analysis software

References Gilat, Amos (2004). MATLAB: An Introduction with Applications 2nd Edition. John Wiley & Sons. ISBN 978-0-471-69420-5.  Quarteroni, Alfio; Saleri, Fausto (2006). Scientific Computing with MATLAB and Octave. Springer. ISBN 978-3-540-32612-0.  Ferreira, A.J.M. (2009). MATLAB Codes for Finite Element Analysis. Springer. ISBN 978-1-4020-9199-5.  Lynch, Stephen (2004). Dynamical Systems with Applications using MATLAB. Birkhäuser. ISBN 978-0-8176-4321-8.