Essential MATLAB for Engineers and Scientists (2013)

APPENDIX C

Command and Function: Quick Reference

This appendix lists most of the MATLAB commands and functions used in the text, along with a few others. For a complete list by category (with links to detailed descriptions) see MATLAB: Reference: MATLAB Function Reference: Functions by Category in the online documentation.

The command help by itself displays a list of all the function categories (each in its own directory).

C.1. General-purpose commands

demo	Run demos
help	Online help
helpwin	Display categories of functions with links to each category
lookfor	Keyword search through help entries
type	List M-files
what	Directory listing of M- and MAT-files
which	Locate functions and files

C.1.1. Managing variables and the workspace

clear	Clear variables and functions from memory
disp	Display matrix or text
length	Length of vector
load	Retrieve variables from disk
save	Save workspace variables to disk
size	Array dimensions
who, whos	List variables in workspace

C.1.2. Files and the operating system

beep	Produce beep sound
cd	Change current working directory
delete	Delete file
diary	Save text of MATLAB session
dir	Directory listing
edit	Edit M-file
!	Execute operating system command

C.1.3. Controlling the Command Window

clc	Clear Command Window
echo	Echo commands in script
format	Set output format for disp
home	Send cursor home
more	Control paged output

C.1.4. Starting and quitting MATLAB

exit	Terminate MATLAB
quit	Terminate MATLAB
startup	Execute M-file when MATLAB starts

C.2. Logical functions

all	True if all elements of vector are true (nonzero)
any	True if any element of vector is true
exist	Check if variable or file exists
find	Find indices of nonzero elements
is*	Detect various states
logical	Convert numeric values to logical values

C.3. MATLAB programming tools

error	Display error message
eval	Interpret string containing MATLAB expression
feval	Function evaluation
for	Repeat statement specific number of times
global	Define global variable
if	Conditionally execute statements
persistent	Define persistent variable
switch	Switch among several cases
try	Begin try block
while	Repeat statements conditionally

C.3.1. Interactive input

input	Prompt user for input
keyboard	Invoke keyboard as script file
menu	Generate menu of choices for user input
pause	Wait for user response

C.4. Matrices

eye	Identity matrix
linspace	Vector with linearly spaced elements
ones	Matrix of ones
rand	Uniformly distributed random numbers and arrays
randn	Normally distributed random numbers and arrays
zeros	Matrix of zeros
: (colon)	Vector with regularly spaced elements

C.4.1. Special variables and constants

ans	Most recent answer
eps	Floating-point relative accuracy
i or j
Inf	Infinity
NaN	Not-a-Number
nargin, nargout	Number of actual function arguments
pi	3.14159 26535 897 …
realmax	Largest positive floating-point number
realmin	Smallest positive floating-point number
varargin, varargout	Pass or return variable numbers of arguments

C.4.2. Time and date

calendar	Calendar
clock	Wall clock (complete date and time)
date	Actual date
etime	Elapsed time
tic, toc	Stopwatch
weekday	Day of week

C.4.3. Matrix manipulation

cat	Concatenate arrays
diag	Create or extract diagonal
fliplr	Flip in left/right direction
flipud	Flip in up/down direction
repmat	Replicate and tile array
reshape	Change shape
rot90	Rotate 90^∘
tril	Extract lower tridiagonal part
triu	Extract upper tridiagonal part

C.4.4. Specialized matrices

gallery	Test matrices
hilb	Hilbert matrix
magic	Magic square
pascal	Pascal matrix
wilkinson	Wilkinson's eigenvalue test matrix

C.5. Mathematical functions

abs	Absolute value
acos, acosh	Inverse cosine, inverse hyperbolic cosine
acot, acoth	Inverse cotangent, inverse hyperbolic cotangent
acsc, acsch	Inverse cosecant, and inverse hyperbolic cosecant
angle	Phase angle
asec, asech	Inverse secant, inverse hyperbolic secant
asin, asinh	Inverse sine, inverse hyperbolic sine
atan, atanh	Inverse tangent (two quadrant), inverse hyperbolic tangent
atan2	Inverse tangent (four quadrant)
bessel	Bessel function
ceil	Round up
conj	Complex conjugate
cos, cosh	Cosine, hyperbolic cosine
cot, coth	Cotangent, hyperbolic cotangent
csc, csch	Cosecant, hyperbolic cosecant
erf	Error function
exp	Exponential
fix	Round toward zero
floor	Round down
gamma	Gamma function
imag	Imaginary part
log	Natural logarithm
log2	Dissect floating-point numbers into exponent and mantissa
log10	Common logarithm
mod	Modulus (signed remainder after division)
rat	Rational approximation
real	Real part
rem	Remainder after division
round	Round toward nearest integer
sec, sech	Secant, hyperbolic secant
sign	Signum function
sin, sinh	Sine, hyperbolic sine
sqrt	Square root
tan, tanh	Tangent, hyperbolic tangent

C.6. Matrix functions

det	Determinant
eig	Eigenvalues and eigenvectors
expm	Matrix exponential
inv	Matrix inverse
poly	Characteristic polynomial
rank	Number of linearly independent rows or columns
rcond	Condition estimator
trace	Sum of diagonal elements
{}\ and /	Linear equation solution

C.7. Data analysis

cumprod	Cumulative product
cumsum	Cumulative sum
diff	Difference function
fft	One-dimensional fast Fourier transform
max	Largest element
mean	Average value of elements
median	Median value of elements
min	Smallest element
prod	Product of elements
sort	Sort in ascending order
std	Standard deviation
sum	Sum of elements
trapz	Trapezoidal rule for numerical integration

C.8. Polynomial functions

polyfit	Fit polynomial to data
polyval	Evaluate polynomial
roots	Find polynomial roots

C.9. Function functions

bvp4c	Solve two-point boundary value problems for ODEs
fmin	Minimize function of one variable
fmins	Minimize function of several variables
fzero	Find zero of function of one variable
ode23, ode23s,
ode45	Solve initial value problems for ODEs
quad	Numerical integration

C.10. Sparse matrix functions

full	Convert sparse matrix to full matrix
sparse	Construct sparse matrix from nonzeros and subscripts
spy	Visualize sparse matrix

C.11. Character string functions

char	characters from ASCII codes
double	ASCII codes of characters
lower	Convert string to lower case
sprintf	Write formatted data to string
str2mat	String-to-matrix conversion
strcat	String concatenation
strcmp	Compare strings
upper	Convert string to upper case

C.12. File I/O functions

fclose	Close one or more open files
feof	Test for end-of-file
fopen	Open file or obtain information about open files
fprintf	Write formatted data to file
fread	Read binary data from file
fscanf	Read formatted data from file
fseek	Set file position indicator
ftell	Get file position indicator
fwrite	Write binary data to file

C.13. 2D graphics

bar	Bar graph
grid	Grid lines
hist	Histogram plot
loglog	Log-log scale plot
plot	Linear plot
polar	Polar coordinate plot
semilogx	Semi-log scale plot
semilogy	Semi-log scale plot
text	Text annotation
title	Graph title
xlabel	x-axis label
ylabel	y-axis label
zoom	Zoom in and out on 2D plot

C.14. 3D graphics

clabel	Contour plot elevation label
comet3	Animated 3D plot
contour	Contour plot in 2D
contour3	Contour plot in 3D
mesh	3D mesh surface
meshc	3D mesh surface with contour plot
meshgrid	X and Y arrays for 3D plots
plot3	Line plot in 3D
quiver	Quiver plot
surf	Shaded surface
surfl	Shaded surface with lighting
view	Rotation of 3D figure
zlabel	z-axis label

C.15. General

axes	Create axes object
axis	Control axis scaling and appearance
cla	Clear axes
clf	Clear current figure
colorbar	Display color bar (color scale)
colormap	Set color look-up table (list of colormaps)
drawnow	Complete any pending drawing
figure	Create figure (graph) windows
fplot	Plot function

gca	Get current axes handle
gcf	Get current figure handle
gco	Return handle of current graphics object
get	Get graphics object properties
ginput	Graphical input from mouse or cursor
gtext	Mouse placement of text
set	Set graphics object properties
subplot	Create axes in tiled positions