mathworks documentation - matlab v7 function references

1 Functions — By Categoryuser-defined options Command Window and History commandhistory Open Command History window, or select it if already opencommandwindow Open Command Window, or sel

MATLAB ® 7

Function Reference: Volume 1 (A-E)

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MATLAB Function Reference

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Revision History

December 1996 First printing For MATLAB 5.0 (Release 8)

June 1997 Online only Revised for MATLAB 5.1 (Release 9) October 1997 Online only Revised for MATLAB 5.2 (Release 10) January 1999 Online only Revised for MATLAB 5.3 (Release 11) June 1999 Second printing For MATLAB 5.3 (Release 11)

June 2001 Online only Revised for MATLAB 6.1 (Release 12.1) July 2002 Online only Revised for 6.5 (Release 13)

June 2004 Online only Revised for 7.0 (Release 14)

September 2006 Online only Revised for 7.3 (Release 2006b) September 2007 Online only Revised for 7.5 (Release 2007b)

Functions — By Category 1

Desktop Tools and Development Environment . 1-3

Startup and Shutdown . 1-3

Command Window and History . 1-4

Help for Using MATLAB . 1-5

Workspace, Search Path, and File Operations . 1-6

Interpolation and Computational Geometry . 1-28

Cartesian Coordinate System Conversion . 1-31

Nonlinear Numerical Methods . 1-31

Filtering and Convolution . 1-42

Interpolation and Regression . 1-42

Fourier Transforms . 1-43

Derivatives and Integrals . 1-43

Time Series Objects . 1-44

Time Series Collections . 1-47

Programming and Data Types . 1-49

Data Types . 1-49

Data Type Conversion . 1-58

File Name Construction . 1-76

Opening, Loading, Saving Files . 1-77

Creating Graphical User Interfaces . 1-104

Predefined Dialog Boxes . 1-104

Deploying User Interfaces . 1-105

Developing User Interfaces . 1-105

Finding Objects from Callbacks . 1-107

GUI Utility Functions . 1-107

Controlling Program Execution . 1-108

Serial Port Devices . 1-113

Functions — Alphabetical List 2

Index

Mathematics (p 1-13) Arrays and matrices, linear algebra,

other areas of mathematicsData Analysis (p 1-41) Basic data operations, descriptive

statistics, covariance and correlation,filtering and convolution, numericalderivatives and integrals, Fouriertransforms, time series analysisProgramming and Data Types

(p 1-49)

Function/expression evaluation,program control, function handles,object oriented programming, errorhandling, operators, data types,dates and times, timers

File I/O (p 1-76) General and low-level file I/O, plus

specific file formats, like audio,spreadsheet, HDF, imagesGraphics (p 1-86) Line plots, annotating graphs,

specialized plots, images, printing,Handle Graphics

3-D Visualization (p 1-97) Surface and mesh plots, view control,

lighting and transparency, volumevisualization

External Interfaces (p 1-109) Interfaces to DLLs, Java, COM and

ActiveX, Web services, and serialport devices, and C and Fortranroutines

Desktop Tools and Development Environment

Desktop Tools and Development Environment

Startup and Shutdown (p 1-3) Startup and shutdown options,

preferencesCommand Window and History

(p 1-4)

Control Command Window andHistory, enter statements and runfunctions

Help for Using MATLAB (p 1-5) Command line help, online

documentation in the Help browser,demos

Workspace, Search Path, and FileOperations (p 1-6)

Work with files, MATLAB searchpath, manage variables

Programming Tools (p 1-8) Edit and debug M-files, improve

performance, source control, publishresults

System (p 1-11) Identify current computer, license,

product version, and more

Startup and Shutdown

matlab (UNIX) Start MATLAB (UNIX systems)matlab (Windows) Start MATLAB (Windows systems)

single-user systems or systemadministrators

prefdir Directory containing preferences,

history, and layout filespreferences Open Preferences dialog box for

MATLAB and related products

1 Functions — By Category

user-defined options

Command Window and History

commandhistory Open Command History window, or

select it if already opencommandwindow Open Command Window, or select it

if already open

resultformat Set display format for outputhome Move cursor to upper-left corner of

Command Windowmatlabcolon (matlab:) Run specified function via hyperlink

Windowperl Call Perl script using appropriate

operating system executablesystem Execute operating system command

and return result

result

Desktop Tools and Development Environment

Help for Using MATLAB

builddocsearchdb Build searchable documentation

database

browser

docsearch Open Help browser Search pane

and search for specified termechodemo Run M-file demo step-by-step in

Command Window

Command Windowhelpbrowser Open Help browser to access all

online documentation and demoshelpwin Provide access to M-file help for all

functions

MathWorkslookfor Search for keyword in all help

entriesplayshow Run M-file demo (deprecated; use

support Open MathWorks Technical Support

Web pageweb Open Web site or file in Web browser

or Help browserwhatsnew Release Notes for MathWorks

products

1 Functions — By Category

Workspace, Search Path, and File Operations

Workspace (p 1-6) Manage variablesSearch Path (p 1-6) View and change MATLAB search

pathFile Operations (p 1-7) View and change files and directories

Workspace

assignin Assign value to variable in specified

workspace

freeing up system memory

specified workspaceexist Check existence of variable, function,

directory, or Java classopenvar Open workspace variable in Array

Editor or other tool for graphicalediting

uiimport Open Import Wizard to import data

workspace Open Workspace browser to manage

Desktop Tools and Development Environment

search pathpath2rc Save current MATLAB search path

pathdef Directories in MATLAB search path

pathsep Path separator for current platform

pathtool Open Set Path dialog box to view

and change MATLAB pathrestoredefaultpath Restore default MATLAB search

path

search pathsavepath Save current MATLAB search path

File Operations

See also “File I/O” on page 1-76 functions

delete Remove files or graphics objects

exist Check existence of variable, function,

directory, or Java classfileattrib Set or get attributes of file or

directoryfilebrowser Current Directory browser

directorylookfor Search for keyword in all help

1 Functions — By Category

matlabroot Root directory of MATLAB

installation

recycle Set option to move deleted files to

recycle folderrehash Refresh function and file system

path caches

toolboxdir Root directory for specified toolbox

web Open Web site or file in Web browser

control systemPublishing (p 1-10) Publish M-file code and results

Desktop Tools and Development Environment

Edit and Debug M-Files

clipboard Copy and paste strings to and from

system clipboarddatatipinfo Produce short description of input

variable

when in debug mode

dbstep Execute one or more lines from

current breakpoint

dbtype List M-file with line numbers

debug List M-file debugging functions

Improve Performance and Tune M-Files

mlint Check M-files for possible problems

mlintrpt Run mlint for file or directory,

reporting results in browser

1 Functions — By Category

profsave Save profile report in HTML formatrehash Refresh function and file system

path caches

Source Control

checkin Check files into source control

system (UNIX)checkout Check files out of source control

system (UNIX)cmopts Name of source control systemcustomverctrl Allow custom source control system

(UNIX)undocheckout Undo previous checkout from source

control system (UNIX)verctrl Source control actions (Windows)

Publishing

published to HTMLnotebook Open M-book in Microsoft Word

(Windows)publish Publish M-file containing cells,

saving output to file of specified type

Desktop Tools and Development Environment

System

Operating System Interface (p 1-11) Exchange operating system

information and commands withMATLAB

MATLAB Version and License

(p 1-12)

Information about MATLAB versionand license

Operating System Interface

clipboard Copy and paste strings to and from

system clipboardcomputer Information about computer on

which MATLAB is running

result

hostid MATLAB server host identification

numbermaxNumCompThreads Controls maximum number of

computational threadsperl Call Perl script using appropriate

operating system executable

system Execute operating system command

and return result

resultwinqueryreg Item from Microsoft Windows

registry

1 Functions — By Category

MATLAB Version and License

Macintosh OS X versions ofMATLAB

version of MATLABisstudent Determine whether Student Version

of MATLABisunix Determine whether UNIX version of

MATLABjavachk Generate error message based on

Java feature supportlicense Return license number or perform

licensing taskprefdir Directory containing preferences,

history, and layout filesusejava Determine whether Java feature is

supported in MATLAB

productsverLessThan Compare toolbox version to specified

version string

Mathematics

Arrays and Matrices (p 1-14) Basic array operators and operations,

creation of elementary andspecialized arrays and matricesLinear Algebra (p 1-19) Matrix analysis, linear equations,

eigenvalues, singular values,logarithms, exponentials,factorization

Elementary Math (p 1-23) Trigonometry, exponentials and

logarithms, complex values,rounding, remainders, discrete mathPolynomials (p 1-28) Multiplication, division, evaluation,

roots, derivatives, integration,eigenvalue problem, curve fitting,partial fraction expansion

Interpolation and ComputationalGeometry (p 1-28)

Interpolation, Delaunaytriangulation and tessellation,convex hulls, Voronoi diagrams,domain generation

Cartesian Coordinate SystemConversion (p 1-31)

Conversions between Cartesian andpolar or spherical coordinatesNonlinear Numerical Methods

(p 1-31)

Differential equations, optimization,integration

Specialized Math (p 1-35) Airy, Bessel, Jacobi, Legendre, beta,

elliptic, error, exponential integral,gamma functions

Sparse Matrices (p 1-36) Elementary sparse matrices,

operations, reordering algorithms,linear algebra, iterative methods,tree operations

Math Constants (p 1-39) Pi, imaginary unit, infinity,

Not-a-Number, largest and smallestpositive floating point numbers,

1 Functions — By Category

Arrays and Matrices

Basic Information (p 1-14) Display array contents, get array

information, determine array typeOperators (p 1-15) Arithmetic operators

Elementary Matrices and Arrays(p 1-16)

Create elementary arrays of differenttypes, generate arrays for plotting,array indexing, etc

Array Operations (p 1-17) Operate on array content, apply

function to each array element, findcumulative product or sum, etc.Array Manipulation (p 1-17) Create, sort, rotate, permute,

reshape, and shift array contentsSpecialized Matrices (p 1-18) Create Hadamard, Companion,

Hankel, Vandermonde, Pascalmatrices, etc

Basic Information

display Display text or array (overloaded

method)isempty Determine whether array is empty

isequalwithequalnans Test arrays for equality, treating

NaNs as equalisfinite Array elements that are finite

floating-point arrayisinf Array elements that are infiniteisinteger Determine whether input is integer

array

islogical Determine whether input is logical

array

isnumeric Determine whether input is numeric

arrayisscalar Determine whether input is scalar

issparse Determine whether input is sparse

isvector Determine whether input is vector

subscripted array expression

\ Backslash or left matrix divide

/ Slash or right matrix divide

.’ Nonconjugated transpose

1 Functions — By Category

.^ Array power (element-wise).\ Left array divide (element-wise)./ Right array divide (element-wise)

Elementary Matrices and Arrays

blkdiag Construct block diagonal matrix

from input argumentsdiag Diagonal matrices and diagonals of

matrix

freqspace Frequency spacing for frequency

responseind2sub Subscripts from linear indexlinspace Generate linearly spaced vectorslogspace Generate logarithmically spaced

vectorsmeshgrid GenerateXandYarrays for 3-D plotsndgrid Generate arrays for N-D functions

and interpolation

pseudorandom numbers

numberssub2ind Single index from subscripts

Array Operations

See “Linear Algebra” on page 1-19 and “Elementary Math” on page 1-23 for

other array operations

accumarray Construct array with accumulation

arrayfun Apply function to each element of

arraybsxfun Apply element-by-element binary

operation to two arrays withsingleton expansion enabledcast Cast variable to different data type

idivide Integer division with rounding

option

Array Manipulation

blkdiag Construct block diagonal matrix

from input arguments

dimensioncircshift Shift array circularly

1 Functions — By Category

diag Diagonal matrices and diagonals of

matrixend Terminate block of code, or indicate

last array indexflipdim Flip array along specified dimension

horzcat Concatenate arrays horizontally

ipermute Inverse permute dimensions of N-D

arraypermute Rearrange dimensions of N-D array

sort Sort array elements in ascending or

descending ordersortrows Sort rows in ascending order

vertcat Concatenate arrays vertically

Specialized Matrices

rosser Classic symmetric eigenvalue test

problem

wilkinson Wilkinson’s eigenvalue test matrix

Linear Algebra

Matrix Analysis (p 1-19) Compute norm, rank, determinant,

condition number, etc

Linear Equations (p 1-20) Solve linear systems, least

squares, LU factorization, Choleskyfactorization, etc

Eigenvalues and Singular Values

(p 1-21)

Eigenvalues, eigenvectors, Schurdecomposition, Hessenburgmatrices, etc

Matrix Logarithms and Exponentials

(p 1-22)

Matrix logarithms, exponentials,square root

Factorization (p 1-22) Cholesky, LU, and QR factorizations,

diagonal forms, singular valuedecomposition

Matrix Analysis

inversioncondeig Condition number with respect to

1 Functions — By Category

rcond Matrix reciprocal condition number

estimate

subspace Angle between two subspaces

Linear Equations

cholinc Sparse incomplete Cholesky and

Cholesky-Infinity factorizations

inversioncondest 1-norm condition number estimate

linsolve Solve linear system of equationslscov Least-squares solution in presence

of known covariancelsqnonneg Solve nonnegative least-squares

constraints problem

luinc Sparse incomplete LU factorization

matrix

decompositionrcond Matrix reciprocal condition number

estimate

Eigenvalues and Singular Values

eigenvalue accuracycdf2rdf Convert complex diagonal form to

real block diagonal formcondeig Condition number with respect to

eigenvalues

eigenvectors of sparse matrix

decomposition

ordeig Eigenvalues of quasitriangular

matrices

factorizationordschur Reorder eigenvalues in Schur

factorization

polyeig Polynomial eigenvalue problem

1 Functions — By Category

rsf2csf Convert real Schur form to complex

Schur form

parameters to transfer functionform

Matrix Logarithms and Exponentials

Factorization

eigenvalue accuracycdf2rdf Convert complex diagonal form to

real block diagonal form

cholinc Sparse incomplete Cholesky and

Cholesky-Infinity factorizationscholupdate Rank 1 update to Cholesky

luinc Sparse incomplete LU factorization

decomposition

factorizationqrinsert Insert column or row into QR

factorizationqrupdate

eigenvaluesrsf2csf Convert real Schur form to complex

root functionsComplex (p 1-26) Numbers with real and imaginary

components, phase anglesRounding and Remainder (p 1-27) Rounding, modulus, and remainder

Discrete Math (e.g., Prime Factors)

(p 1-27)

Prime factors, factorials,permutations, rational fractions,least common multiple, greatestcommon divisor

1 Functions — By Category

Trigonometric

acos Inverse cosine; result in radiansacosd Inverse cosine; result in degrees

acot Inverse cotangent; result in radiansacotd Inverse cotangent; result in degrees

acsc Inverse cosecant; result in radiansacscd Inverse cosecant; result in degrees

asec Inverse secant; result in radiansasecd Inverse secant; result in degrees

asin Inverse sine; result in radiansasind Inverse sine; result in degrees

atan Inverse tangent; result in radians

atand Inverse tangent; result in degrees

radians

Exponential

small values ofx

small values ofx

floating-point numbers intoexponent and mantissa

nthroot Realnth root of real numbers

pow2 Base 2 power and scale floating-point

1 Functions — By Category

reallog Natural logarithm for nonnegative

real arraysrealpow Array power for real-only outputrealsqrt Square root for nonnegative real

complex Construct complex data from real

and imaginary components

cplxpair Sort complex numbers into complex

conjugate pairs

isreal Determine whether input is real

array

unwrap Correct phase angles to produce

smoother phase plots

Rounding and Remainder

idivide Integer division with rounding

option

Discrete Math (e.g., Prime Factors)

isprime Array elements that are prime

numbers

nchoosek Binomial coefficient or all

combinations

primes Generate list of prime numbers

rat, rats Rational fraction approximation

polyeig Polynomial eigenvalue problem

polyint Integrate polynomial analytically

polyvalm Matrix polynomial evaluationresidue Convert between partial fraction

expansion and polynomialcoefficients

Interpolation and Computational Geometry

Interpolation (p 1-29) Data interpolation, data gridding,

polynomial evaluation, nearest pointsearch

Delaunay Triangulation andTessellation (p 1-30)

Delaunay triangulation andtessellation, triangular surface andmesh plots

Convex Hull (p 1-30) Plot convex hull, plotting functionsVoronoi Diagrams (p 1-30) Plot Voronoi diagram, patch graphics

object, plotting functionsDomain Generation (p 1-31) Generate arrays for 3-D plots, or for

N-D functions and interpolation

Interpolation

dsearch Search Delaunay triangulation for

nearest point

griddata3 Data gridding and hypersurface

fitting for 3-D datagriddatan Data gridding and hypersurface

fitting (dimension >= 2)interp1 1-D data interpolation (table lookup)

interp1q Quick 1-D linear interpolation

interp2 2-D data interpolation (table lookup)

interp3 3-D data interpolation (table lookup)

interpft 1-D interpolation using FFT method

interpn N-D data interpolation (table lookup)

meshgrid GenerateXandYarrays for 3-D plots

ndgrid Generate arrays for N-D functions

and interpolationpadecoef Padé approximation of time delays

Interpolating Polynomial (PCHIP)

spline Cubic spline data interpolation

tsearchn N-D closest simplex search

1 Functions — By Category

Delaunay Triangulation and Tessellation

delaunay3 3-D Delaunay tessellationdelaunayn N-D Delaunay tessellationdsearch Search Delaunay triangulation for

nearest point

tsearch Search for enclosing Delaunay

triangletsearchn N-D closest simplex search

Convex Hull

Domain Generation

meshgrid GenerateXandYarrays for 3-D plots

ndgrid Generate arrays for N-D functions

and interpolation

Cartesian Coordinate System Conversion

cart2pol Transform Cartesian coordinates to

polar or cylindricalcart2sph Transform Cartesian coordinates to

sphericalpol2cart Transform polar or cylindrical

coordinates to Cartesiansph2cart Transform spherical coordinates to

Cartesian

Nonlinear Numerical Methods

Ordinary Differential Equations

(IVP) (p 1-32)

Solve stiff and nonstiff differentialequations, define the problem, setsolver options, evaluate solutionDelay Differential Equations

(p 1-33)

Solve delay differential equationswith constant and general delays,set solver options, evaluate solutionBoundary Value Problems (p 1-33) Solve boundary value problems for

ordinary differential equations, setsolver options, evaluate solution

Optimization (p 1-34) Find minimum of single and

multivariable functions, solvenonnegative least-squares constraintproblem

Numerical Integration (Quadrature)(p 1-34)

Evaluate Simpson, Lobatto, andvectorized quadratures, evaluatedouble and triple integrals

Ordinary Differential Equations (IVP)

decic Compute consistent initial conditions

deval Evaluate solution of differential

equation problemode15i Solve fully implicit differential

equations, variable order methodode23, ode45, ode113, ode15s,

ode23s, ode23t, ode23tb

Solve initial value problems forordinary differential equationsodefile Define differential equation problem

for ordinary differential equationsolvers

odeget Ordinary differential equation

options parametersodeset Create or alter options structure

for ordinary differential equationsolvers

odextend Extend solution of initial value

problem for ordinary differentialequation