MatLab Reference

MatLab Reference

General purpose commands. (MATLAB Toolbox Version 4.2 2-Nov-93)

Managing commands and functions.

help On-line documentation.

what Directory listing of M-, MAT- and MEX-files.

type List M-file.

lookfor Keyword search through the HELP entries.

which Locate functions and files.

demo Run demos.

path Control MATLAB's search path.

Managing variables and the workspace.

who List current variables.

whos List current variables, long form.

load Retrieve variables from disk.

save Save workspace variables to disk.

clear Clear variables and functions from memory.

pack Consolidate workspace memory.

size Size of matrix.

length Length of vector.

disp Display matrix or text.

Working with files and the operating system.

cd Change current working directory.

dir Directory listing.

delete Delete file.

getenv Get environment value.

! Execute operating system command.

unix Execute operating system command & return result.

diary Save text of MATLAB session.

Controlling the command window.

cedit Set command line edit/recall facility parameters.

clc Clear command window.

home Send cursor home.

format Set output format.

echo Echo commands inside script files.

more Control paged output in command window.

Starting and quitting from MATLAB.

quit Terminate MATLAB.

startup M-file executed when MATLAB is invoked.

matlabrc Master startup M-file.

General information.

info Information about MATLAB and The MathWorks, Inc.

subscribe Become subscribing user of MATLAB.

hostid MATLAB server host identification number.

whatsnew Information about new features not yet documented.

ver MATLAB, SIMULINK, and TOOLBOX version information.

Operators and special characters.

Char Name

+ Plus

- Minus

* Matrix multiplication

.* Array multiplication

^ Matrix power

.^ Array power

\ Backslash or left division

/ Slash or right division

./ Array division

kron Kronecker tensor product

: Colon

( ) Parentheses

[ ] Brackets

. Decimal point

.. Parent directory

... Continuation

, Comma

; Semicolon

% Comment

! Exclamation point

' Transpose and quote

= Assignment

== Equality

< > Relational operators

& Logical AND

| Logical OR

~ Logical NOT

xor Logical EXCLUSIVE OR

Logical characteristics.

exist Check if variables or functions are defined.

any True if any element of vector is true.

all True if all elements of vector are true.

find Find indices of non-zero elements.

isnan True for Not-A-Number.

isinf True for infinite elements.

finite True for finite elements.

isempty True for empty matrix.

isreal True for real matrix.

issparse True for sparse matrix.

isstr True for text string.

isglobal True for global variables.

Elementary math functions.

Trigonometric.

sin Sine.

sinh Hyperbolic sine.

asin Inverse sine.

asinh Inverse hyperbolic sine.

cos Cosine.

cosh Hyperbolic cosine.

acos Inverse cosine.

acosh Inverse hyperbolic cosine.

tan Tangent.

tanh Hyperbolic tangent.

atan Inverse tangent.

atan2 Four quadrant inverse tangent.

atanh Inverse hyperbolic tangent.

sec Secant.

sech Hyperbolic secant.

asec Inverse secant.

asech Inverse hyperbolic secant.

csc Cosecant.

csch Hyperbolic cosecant.

acsc Inverse cosecant.

acsch Inverse hyperbolic cosecant.

cot Cotangent.

coth Hyperbolic cotangent.

acot Inverse cotangent.

acoth Inverse hyperboliccotangent.

Exponential.

exp Exponential.

log Natural logarithm.

log10 Common logarithm.

sqrt Square root.

Complex.

abs Absolute value.

angle Phase angle.

conj Complex conjugate.

imag Complex imaginary part.

real Complex real part.

Numeric.

fix Round towards zero.

floor Round towards minus infinity.

ceil Round towards plus infinity.

round Round towards nearest integer.

rem Remainder after division.

sign Signum function.

Specialized math functions.

besselj Bessel function of the first kind.

bessely Bessel function of the second kind.

besseli Modified Bessel function of the first kind.

besselk Modified Bessel function of the second kind.

beta Beta function.

betainc Incomplete beta function.

betaln Logarithm of beta function.

ellipj Jacobi elliptic functions.

ellipke Complete elliptic integral.

erf Error function.

erfc Complementary error function.

erfcx Scaled complementary error function.

erfinv Inverse error function.

expint Exponential integral function.

gamma Gamma function.

gcd Greatest common divisor.

gammainc Incomplete gamma function.

lcm Least common multiple.

legendre Associated Legendre function.

gammaln Logarithm of gamma function.

log2 Dissect floating point numbers.

pow2 Scale floating point numbers.

rat Rational approximation.

rats Rational output.

cart2sph Transform from Cartesian to spherical coordinates.

cart2pol Transform from Cartesian to polar coordinates.

pol2cart Transform from polar to Cartesian coordinates.

sph2cart Transform from spherical to Cartesian coordinates.

Elementary matrices and matrix manipulation.

Elementary matrices.

zeros Zeros matrix.

ones Ones matrix.

eye Identity matrix.

rand Uniformly distributed random numbers.

randn Normally distributed random numbers.

linspace Linearly spaced vector.

logspace Logarithmically spaced vector.

meshgrid X and Y arrays for 3-D plots.

: Regularly spaced vector.

Special variables and constants.

ans Most recent answer.

eps Floating point relative accuracy.

realmax Largest floating point number.

realmin Smallest positive floating point number.

pi 3.1415926535897....

i, j Imaginary unit.

inf Infinity.

NaN Not-a-Number.

flops Count of floating point operations.

nargin Number of function input arguments.

nargout Number of function output arguments.

computer Computer type.

isieee True for computers with IEEE arithmetic.

isstudent True for the Student Edition.

why Succinct answer.

version MATLAB version number.

Time and dates.

clock Wall clock.

cputime Elapsed CPU time.

date Calendar.

etime Elapsed time function.

tic, toc Stopwatch timer functions.

Matrix manipulation.

diag Create or extract diagonals.

fliplr Flip matrix in the left/right direction.

flipud Flip matrix in the up/down direction.

reshape Change size.

rot90 Rotate matrix 90 degrees.

tril Extract lower triangular part.

triu Extract upper triangular part.

: Index into matrix, rearrange matrix.

Specialized matrices.

compan Companion matrix.

gallery Several small test matrices.

hadamard Hadamard matrix.

hankel Hankel matrix.

hilb Hilbert matrix.

invhilb Inverse Hilbert matrix.

kron Kronecker tensor product.

magic Magic square.

pascal Pascal matrix.

rosser Classic symmetric eigenvalue test problem.

toeplitz Toeplitz matrix.

vander Vandermonde matrix.

wilkinson Wilkinson's eigenvalue test matrix.

Matrix functions - numerical linear algebra.

Matrix analysis.

cond Matrix condition number.

norm Matrix or vector norm.

rcond LINPACK reciprocal condition estimator.

rank Number of linearly independent rows or columns.

det Determinant.

trace Sum of diagonal elements.

null Null space.

orth Orthogonalization.

rref Reduced row echelon form.

Linear equations.

\ and / Linear equation solution; use "help slash".

chol Cholesky factorization.

lu Factors from Gaussian elimination.

inv Matrix inverse.

qr Orthogonal-triangular decomposition.

qrdelete Delete a column from the QR factorization.

qrinsert Insert a column in the QR factorization.

nnls Non-negative least-squares.

pinv Pseudoinverse.

lscov Least squares in the presence of known covariance.

Eigenvalues and singular values.

eig Eigenvalues and eigenvectors.

poly Characteristic polynomial.

polyeig Polynomial eigenvalue problem.

hess Hessenberg form.

qz Generalized eigenvalues.

rsf2csf Real block diagonal form to complex diagonal form.

cdf2rdf Complex diagonal form to real block diagonal form.

schur Schur decomposition.

balance Diagonal scaling to improve eigenvalue accuracy.

svd Singular value decomposition.

Matrix functions.

expm Matrix exponential.

expm1 M-file implementation of expm.

expm2 Matrix exponential via Taylor series.

expm3 Matrix exponential via eigenvalues and eigenvectors.

logm Matrix logarithm.

sqrtm Matrix square root.

funm Evaluate general matrix function.

Sparse matrix functions.

Elementary sparse matrices.

speye Sparse identity matrix.

sprandn Sparse random matrix.

sprandsym Sparse symmetric random matrix.

spdiags Sparse matrix formed from diagonals.

Full to sparse conversion.

sparse Create sparse matrix from nonzeros and indices.

full Convert sparse matrix to full matrix.

find Find indices of nonzero entries.

spconvert Convert from sparse matrix external format.

Working with nonzero entries of sparse matrices.

nnz Number of nonzero entries.

nonzeros Nonzero entries.

nzmax Amount of storage allocated for nonzero entries.

spones Replace nonzero entries with ones.

spalloc Allocate memory for nonzero entries.

issparse True if matrix is sparse.

spfun Apply function to nonzero entries.

Visualizing sparse matrices.

spy Visualize sparsity structure.

gplot Plot graph, as in "graph theory".

Reordering algorithms.

colmmd Column minimum degree.

symmmd Symmetric minimum degree.

symrcm Reverse Cuthill-McKee ordering.

colperm Order columns based on nonzero count.

randperm Random permutation vector.

dmperm Dulmage-Mendelsohn decomposition.

Norm, condition number, and rank.

normest Estimate 2-norm.

condest Estimate 1-norm condition.

sprank Structural rank.

Operations on trees.

treelayout Lay out a tree or forest.

treeplot Plot a picture of a tree.

etree Elimination tree of a matrix.

etreeplot Plot the elimination tree.

Miscellaneous.

symbfact Symbolic factorization analysis.

spparms Set parameters for sparse matrix routines.

spaugment Form least squares augmented system.

Polynomial and interpolation functions.

Polynomials.

roots Find polynomial roots.

poly Construct polynomial with specified roots.

polyval Evaluate polynomial.

polyvalm Evaluate polynomial with matrix argument.

residue Partial-fraction expansion (residues).

polyfit Fit polynomial to data.

polyder Differentiate polynomial.

conv Multiply polynomials.

deconv Divide polynomials.

Data interpolation.

interp1 1-D interpolation (1-D table lookup).

interp2 2-D interpolation (2-D table lookup).

interpft 1-D interpolation using FFT method.

griddata Data gridding.

Spline interpolation.

spline Cubic spline data interpolation.

ppval Evaluate piecewise polynomial.

Function functions - nonlinear numerical methods.

ode23 Solve differential equations, low order method.

ode23p Solve and plot solutions.

ode45 Solve differential equations, high order method.

quad Numerically evaluate integral, low order method.

quad8 Numerically evaluate integral, high order method.

fmin Minimize function of one variable.

fmins Minimize function of several variables.

fzero Find zero of function of one variable.

fplot Plot function.

See also The Optimization Toolbox, which has a comprehensive

set of function functions for optimizing and minimizing functions.

Symbolic Math Toolbox. Version 1.1 (Student Edition) 5-23-94

Calculus.

diff Differentiate or difference.

int Integrate.

taylor Taylor series.

jacobian Jacobian matrix.

Linear Algebra.

inverse Symbolic matrix inverse.

determ Symbolic matrix determinant.

linsolve Solve simultaneous linear equations.

nullspace Basis for null space.

colspace Basis for column space.

eigensys Symbolic eigenvalues and eigenvectors.

transpose Symbolic matrix transpose.

charpoly Symbolic characteristic polynomial.

jordan Jordan canonical form.

singvals Symbolic singular values and singular vectors.

Simplification.

simplify Simplify.

expand Expand.

factor Factor.

collect Collect.

simple Search for shortest form.

allvalues Find all values for RootOf expression.

symsum Symbolic summation.

Solution of Equations.

solve Symbolic solution of algebraic equations.

dsolve Symbolic solution of differential equations.

finverse Functional inverse.

compose Functional composition.

Variable Precision Arithmetic.

vpa Variable precision arithmetic.

digits Set variable precision accuracy.

Transforms.

fourier Fourier transform.

laplace Laplace transform.

ztrans Z transform.

invfourier Inverse Fourier transform.

invlaplace Inverse Laplace transform.

invztrans Inverse Z transform.

Operations on Symbolic Expressions and Matrices.

numeric Convert symbolic matrix to numeric form.

sym Create or modify symbolic matrix.

symvar Determine symbolic variables.

symop Symbolic operations.

symadd Add symbolic expressions.

symsub Subtract symbolic expressions.

symmul Multiply symbolic expressions.

symdiv Divide symbolic expressions.

sympow Power of symbolic expression.

symsize Size of symbolic matrix.

subs Substitute for subexpression.

numden Numerator and denominator.

poly2sym Coefficient vector to symbolic polynomial.

sym2poly Symbolic polynomial to coefficient vector.

horner Nested polynomial representation.

pretty Pretty print symbolic output.

latex LaTeX represention of symbolic output.

Pedagogical and Graphical Applications.

rsums Riemann sums.

ezplot Easy to use function plotter.

funtool Function calculator.

Character string functions.

General.

strings About character strings in MATLAB.

abs Convert string to numeric values.

setstr Convert numeric values to string.

isstr True for string.

blanks String of blanks.

deblank Remove trailing blanks.

str2mat Form text matrix from individual strings.

eval Execute string with MATLAB expression.

String comparison.

strcmp Compare strings.

findstr Find one string within another.

upper Convert string to uppercase.

lower Convert string to lowercase.

isletter True for letters of the alphabet.

isspace True for white space characters.

strrep Replace a string with another.

strtok Find a token in a string.

String to number conversion.

num2str Convert number to string.

int2str Convert integer to string.

str2num Convert string to number.

sprintf Convert number to string under format control.

sscanf Convert string to number under format control.

Hexadecimal to number conversion.

hex2num Convert hex string to IEEE floating point number.

hex2dec Convert hex string to decimal integer.

dec2hex Convert decimal integer to hex string.

Signals and Systems Toolbox. Version 1.1 (Student Edition) 5-31-94

Digital filter design.

butter Butterworth filter design.

cheby1 Chebyshev type I filter design.

cheby2 Chebyshev type II filter design.

ellip Elliptic filter design.

remez Parks-McClellan optimal FIR filter design.

yulewalk Yule-Walker filter design.

Filter analysis and implementation.

angle Phase angle.

conv Convolution.

grpdelay Group delay.

unwrap Unwrap phase.

Frequency response.

bode Bode plot (frequency response).

freqs Laplace-transform frequency response.

freqz Z-transform frequency response.

nyquist Nyquist plot.

rlocus Evans root-locus.

Analog lowpass filter prototypes.

buttap Butterworth filter prototype.

cheb1ap Chebyshev type I filter prototype (passband ripple).

cheb2ap Chebyshev ty[pe II filter prototype (stopband ripple).

ellipap Elliptic filter prototype.

Frequency translation.

lp2bp Lowpass to bandpass analog filter transformation.

lp2bs Lowpass to bandstop analog filter transformation.

lp2hp Lowpass to highpass analog filter transformation.

lp2lp Lowpass to lowpass analog filter transformation.

Filter discretization.

bilinear Bilinear transformation with optional prewarping.

impinvar Impulse invariance method for analog to digital conversion.

Windows.

boxcar Rectangular window.

hamming Hamming window.

hanning Hanning window.

kaiser BETA-valued N-point Kaiser window.

triang Triangular window.

Statistical signal processing.

corrcoef Correlation coefficients.

cov Covariance matrix.

psd Power Spectral Density.

Specialized operations.

deconv Deconvolution.

detrend Remove a linear trend from a vector.

sinc Sin(pi*x)/(pi*x) function.

specgram Spectrogram, for speech signals.

spline Cubic spline interpolation.

stem Plot discrete sequence data.

strips Strip plot.

zplane Z-plane zero-pole plot.

Linear system transformations.

sos2ss Second-order sections to state-space conversion.

sos2tf Second-order sections to transfer function conversion.

sos2zp Second-order sections to zero-pole conversion.

ss2sos State-space to second-order sections conversion.

ss2tf State-space to transfer function conversion.

ss2zp State-space to zero-pole conversion.

tf2ss Transfer function to state-space conversion.

tf2zp Transfer function to zero-pole conversion.

zp2sos Zero-pole to second-order sections conversion.

zp2ss Zero-pole to state-space conversion.

zp2tf Zero-pole to transfer function conversion.

Model building.

append Append system dynamics.

cloop Close loops of system.

drmodel Generate random discrete model.

feedback Feedback system connection.

rmodel Generate random continuous model.

series Series system connection.

ssselect Select subsystem from larger system.

Model conversions.

c2d Continuous to discrete-time conversion.

c2dm Continuous to discrete-time conversion with method.

poly Roots to polynomial conversion.

residue Partial fraction expansion.

residuez Z-transform partial-fraction expansion.

Model realizations.

canon Canonical form.

Model properties.

ctrb Controllability matrix.

damp Damping factors and natural frequencies.

ddamp Discrete damping factors and natural frequencies.

dsort Sort discrete eigenvalues by magnitude.

esort Sort continuous eigenvalues by real part.

obsv Form observability matrix.

roots Polynomial roots.

tzero Transmission zeros.

Time response.

dimpulse Discrete unit sample response.

dlsim Simulation of discrete-time linear systems.

dstep Discrete step response.

impulse Impulse response of continuous-time linear systems.

lsim Continuous simulation to arbitrary inputs.

ltitr Linear time-invariant time response kernel.

step Step response.

Gain selection.

acker SISO pole placement.

lqe Linear-quadratic estimator design.

lqr Linear-quadratic regulator design.

place Pole placement.

Demonstrations.

sosdemo Second-order sections demonstration.

General purpose graphics functions.

Figure window creation and control.

figure Create Figure (graph window).

gcf Get handle to current figure.

clf Clear current figure.

close Close figure.

Axis creation and control.

subplot Create axes in tiled positions.

axes Create axes in arbitrary positions.

gca Get handle to current axes.

cla Clear current axes.

axis Control axis scaling and appearance.

caxis Control pseudocolor axis scaling.

hold Hold current graph.

Handle Graphics objects.

figure Create figure window.

axes Create axes.

line Create line.

text Create text.

patch Create patch.

surface Create surface.

image Create image.

uicontrol Create user interface control.

uimenu Create user interface menu.

Handle Graphics operations.

set Set object properties.

get Get object properties.

reset Reset object properties.

delete Delete object.

gco Get handle to current object.

drawnow Flush pending graphics events.

newplot M-file preamble for NextPlot property.

findobj Find objects with specified property values.

Hardcopy and storage.

print Print graph or save graph to file.

printopt Configure local printer defaults.

orient Set paper orientation.

capture Screen capture of current figure.

Movies and animation.

moviein Initialize movie frame memory.

getframe Get movie frame.

movie Play recorded movie frames.

Miscellaneous.

ginput Graphical input from mouse.

ishold Return hold state.

graymon Set graphics window defaults for gray-scale monitors.

rbbox Rubberband box.

rotate Rotate an object about a specified direction.

terminal Set graphics terminal type.

uiputfile Put up dialog box for saving files.

uigetfile Put up dialog box which queries for file names.

whitebg Set graphics window defaults for white background.

zoom Zoom in and out on a 2-D plot.

waitforbuttonpress Wait for key/buttonpress over figure.