Matlab Primer (3)

There are many MATLAB features which cannot be included in these introductory notes. Listed below are some of the MATLAB functions and operators available, grouped by subject area. [Source: MATLAB User's Guide, version 3.5] Use the on-line help facility or consult the User's Guide for more detailed information on the functions.

There are many functions beyond these. There exist, in particular, several "toolboxes" of functions for specific areas; included among such are signal processing, control systems, robust-control, system identification, optimization, splines, chemometrics, mu-analysis and synthesis, state-space identification, and neural networks. [The toolboxes, which are optional, may not be installed on your system.] These can be explored via the command help.

[Note: Some of the following tables require a tables-aware browser, such as Netscape 1.1N or later. - Ed.]

General
`help`	help facility
`demo`	run demonstrations
`who`	list variables in memory
`what`	list M-files on disk
`size`	row and column dimensions
`length`	vector length
`clear`	clear workspace
`computer`	type of computer
`^C`	local abort
`exit`	exit MATLAB
`quit`	same as exit

Special Values

`ans`	answer when expression not assigned
`eps`	floating point precision
`pi`	3.14159...
`i, j`	sqrt(-1)
`inf`	infinity
`NaN`	Not-a-Number
`clock`	wall clock
`date`	date
`flops`	floating point operation count
`nargin`	number of function input arguments
`nargout`	number of function output arguments

Disk Files

`chdir`	change current directory
`delete`	delete file
`diary`	diary of the session
`dir`	directory of files on disk
`load`	load variables from file
`save`	save variables to file
`type`	list function or file
`what`	show M-files on disk
`fprintf`	write to a file
`pack`	compact memory via save

Special Matrices

`compan`	companion
`diag`	diagonal
`eye`	identity
`gallery`	esoteric
`hadamard`	Hadamard
`hankel`	Hankel
`hilb`	Hilbert
`invhilb`	inverse Hilbert
`linspace`	linearly spaced vectors
`logspace`	logarithmically spaced vectors
`magic`	magic square
`meshdom`	domain for mesh points
`ones`	constant
`pascal`	Pascal
`rand`	random elements
`toeplitz`	Toeplitz
`vander`	Vandermonde
`zeros`	zero

Matrix Manipulation

`rot90`	rotation
`fliplr`	flip matrix left-to-right
`flipud`	flip matrix up-to-down
`diag`	diagonal matrices
`tril`	lower triangular part
`triu`	upper triangular part
`reshape`	reshape
`.'`	transpose
`:`	convert matrix to single column; `A(:)`

Relational and Logical Functions

`any`	logical conditions
`all`	logical conditions
`find`	find array indices of logical values
`isnan`	detect NaNs
`finite`	detect infinities
`isempty`	detect empty matrices
`isstr`	detect string variables
`strcmp`	compare string variables

Control Flow

`if`	conditionally execute statements
`elseif`	used with `if`
`else`	used with `if`
`end`	terminate `if, for, while`
`for`	repeat statements a number of times
`while`	do while
`break`	break out of `for` and `while` loops
`return`	return from functions
`pause`	pause until key pressed

Programming and M-Files

`input`	get numbers from keyboard
`keyboard`	call keyboard as M-file
`error`	display error message
`function`	define function
`eval`	interpret text in variables
`feval`	evaluate function given by string
`echo`	enable command echoing
`exist`	check if variables exist
`casesen`	set case sensitivity
`global`	define global variables
`startup`	startup M-file
`getenv`	get environment string
`menu`	select item from menu
`etime`	elapsed time

Text and Strings

`abs`	convert string to ASCII values
`eval`	evaluate text macro
`num2str`	convert number to string
`int2str`	convert integer to string
`setstr`	set flag indicating matrix is a string
`sprintf`	convert number to string
`isstr`	detect string variables
`strcomp`	compare string variables
`hex2num`	convert hex string to number

Command Window

`clc`	clear command screen
`home`	move cursor home
`format`	set output display format
`disp`	display matrix or text
`fprintf`	print formatted number
`echo`	enable command echoing

Graph Paper

`plot`	linear X-Y plot
`loglog`	loglog X-Y plot
`semilogx`	semi-log X-Y plot
`semilogy`	semi-log X-Y plot
`polar`	polar plot
`mesh`	3-dimensional mesh surface
`contour`	contour plot
`meshdom`	domain for mesh plots
`bar`	bar charts
`stairs`	stairstep graph
`errorbar`	add error bars

Graph Annotation

`title`	plot title
`xlabel`	x-axis label
`ylabel`	y-axis label
`grid`	draw grid lines
`text`	arbitrarily position text
`gtext`	mouse-positioned text
`ginput`	graphics input

Graph Window Control

`axis`	manual axis scaling
`hold`	hold plot on screen
`shg`	show graph window
`clg`	clear graph window
`subplot`	split graph window

Elementary Math Functions

`abs`	absolute value or complex magnitude
`angle`	phase angle
`sqrt`	square root
`real`	real part
`imag`	imaginary part
`conj`	complex conjugate
`round`	round to nearest integer
`fix`	round toward zero
`floor`	round toward $-\infty$
`ceil`	round toward $\infty$
`sign`	signum function
`rem`	remainder
`exp`	exponential base e
`log`	natural logarithm
`log10`	log base 10

Trigonometric Functions

`sin`	sine
`cos`	cosine
`tan`	tangent
`asin`	arcsine
`acos`	arccosine
`atan`	arctangent
`atan2`	four quadrant arctangent
`sinh`	hyperbolic sine
`cosh`	hyperbolic cosine
`tanh`	hyperbolic tangent
`asinh`	hyperbolic arcsine
`acosh`	hyperbolic arccosine
`atanh`	hyperbolic arctangent

Special Functions

`bessel`	bessel function
`gamma`	gamma function
`rat`	rational approximation
`erf`	error function
`inverf`	inverse error function
`ellipk`	complete elliptic integral of first kind
`ellipj`	Jacobian elliptic integral

Decompositions and Factorizations

`balance`	balanced form
`backsub`	backsubstitution
`cdf2rdf`	convert complex-diagonal to real-diagonal
`chol`	Cholesky factorization
`eig`	eigenvalues and eigenvectors
`hess`	Hessenberg form
`inv`	inverse
`lu`	factors from Gaussian elimination
`nnls`	nonnegative least squares
`null`	null space
`orth`	orthogonalization
`pinv`	pseudoinverse
`qr`	orthogonal-triangular decomposition
`qz`	QZ algorithm
`rref`	reduced row echelon form
`schur`	Schur decomposition
`svd`	singular value decomposition

Matrix Conditioning

`cond`	condition number in 2-norm
`norm`	1-norm,2-norm,F-norm,$\infty$-norm
`rank`	rank
`rcond`	condition estimate (reciprocal)

Elementary Matrix Functions

`expm`	matrix exponential
`logm`	matrix logarithm
`sqrtm`	matrix square root
`funm`	arbitrary matrix function
`poly`	characteristic polynomial
`det`	determinant
`trace`	trace
`kron`	Kronecker tensor product

Polynomials

`poly`	characteristic polynomial
`roots`	polynomial roots---companion matrix method
`roots1`	polynomial roots---Laguerre's method
`polyval`	polynomial evaluation
`polyvalm`	matrix polynomial evaluation
`conv`	multiplication
`deconv`	division
`residue`	partial-fraction expansion
`polyfit`	polynomial curve fitting

Column-wise Data Analysis

`max`	maximum value
`min`	minimum value
`mean`	mean value
`median`	median value
`std`	standard deviation
`sort`	sorting
`sum`	sum of elements
`prod`	product of elements
`cumsum`	cumulative sum of elements
`cumprod`	cumulative product of elements
`diff`	approximate derivatives
`hist`	histograms
`corrcoef`	correlation coefficients
`cov`	covariance matrix
`cplxpair`	reorder into complex pairs

Signal Processing

`abs`	complex magnitude
`angle`	phase angle
`conv`	convolution
`corrcoef`	correlation coefficients
`cov`	covariance
`deconv`	deconvolution
`fft`	radix-2 fast Fourier transform
`fft2`	two-dimensional FFT
`ifft`	inverse fast Fourier transform
`ifft2`	inverse 2-D FFT
`fftshift`	FFT rearrangement

Nonlinear Equations and Optimization

`fmin`	minimum of a function of one variable
`fmins`	minimum of a multivariable function
`fsolve`	solution of a system of nonlinear equations (zeros of a multivariable function)
`fzero`	zero of a function of one variable

19. Reference