This is a good summary of many common MATLAB commands. It is reproduced here in HTML format.
Source: PDF file posted at several sites but originally created by Dr. Brian Vick of Virginia Tech.
Index
General Purpose Commands
Operators and Special Characters
+ |
Plus;
addition operator. |
- |
Minus;
subtraction operator. |
* |
Scalar
and matrix multiplication operator. |
.* |
Array
multiplication operator. |
^ |
Scalar
and matrix exponentiation operator. |
.^ |
Array
exponentiation operator. |
\ |
Left-division
operator. |
/ |
Right-division
operator. |
.\ |
Array
left-division operator. |
./ |
Array
right-division operator. |
: |
Colon;
generates regularly spaced elements and represents an entire row or column. |
( ) |
Parentheses;
encloses function arguments and array indices; overrides precedence. |
[ ] |
Brackets;
enclosures array elements. |
. |
Decimal
point. |
… |
Ellipsis;
line-continuation operator. |
, |
Comma;
separates statements and elements in a row. |
; |
Semicolon;
separates columns and suppresses display. |
% |
Percent
sign; designates a comment and specifies formatting. |
’ |
Quote
sign and transpose operator. |
.’ |
Nonconjugated
transpose operator. |
= |
Assignment
(replacement) operator. |
Commands for Managing a Session
clc |
Clears
Command window. |
clear |
Removes
variables from memory. |
exist |
Checks
for existence of file or variable. |
global |
Declares
variables to be global. |
help |
Searches
for a help topic. |
lookfor |
Searches
help entries for a keyword. |
quit |
Stops
MATLAB. |
who |
Lists
current variables. |
whos |
Lists
current variables (long display). |
Special Variables and Constants
ans | Most recent answer |
eps | Accuracy of floating-point precision |
i,j | The imaginary unit sqrt(-1) |
Inf | Infinity |
NaN | Undefined numerical result (not a number) |
pi | The number 3.14159... |
System and File Commands
cd |
Changes
current directory. |
date |
Displays
current date. |
delete |
Deletes a
file. |
diary |
Switches
on/off diary file recording. |
dir |
Lists all
files in current directory. |
load |
Loads
workspace variables from a file. |
path |
Displays
search path. |
pwd |
Displays
current directory. |
save |
Saves
workspace variables in a file. |
type |
Displays
contents of a file. |
what |
Lists all
MATLAB files in the current directory. |
wklread |
Reads
.wk1 spreadsheet file. |
Input/Output and Formatting Commands
Input/Output Commands
disp |
Displays
contents of an array or string. |
fscanf |
Read
formatted data from a file. |
format |
Controls
screen-display format. |
fprintf |
Performs formatted writes to screen or file. |
sprintf |
Performs formatted writes to a text variable. |
input |
Displays
prompts and waits for input. |
; |
Suppresses
screen printing. |
[txt1 txt2 'literal'] |
Concatenate text |
{ txt1, txt2, 'literal' } |
Use a cell array to represent multi-line text |
Format Codes for fprintf and fscanf
Format Codes for fprintf and fscanf |
%s |
Format as
a string. |
%d |
Format as
an integer. |
%f |
Format as
a floating point value. |
%e |
Format as
a floating point value in scientific notation. |
%g |
Format in
the most compact form: %f or %e. |
\n |
Insert a
new line in the output string. |
\t |
Insert a
tab in the output string. |
Numeric Display Format
format short |
Four
decimal digits (default). |
format long |
16
decimal digits. |
format short e |
Five
digits plus exponent. |
format long
e |
16 digits
plus exponents. |
format bank |
Two
decimal digits. |
format + |
Positive,
negative, or zero. |
format rat |
Rational
approximation. |
format compact |
Suppresses
some line feeds. |
format loose |
Resets to
less compact display mode. |
Vector, Matrix and Array Commands
Array Commands
cat |
Concatenates
arrays. |
find |
Finds
indices of nonzero elements. |
length |
Computers
number of elements. |
linspace |
Creates
regularly spaced vector. |
logspace |
Creates
logarithmically spaced vector. |
max |
Returns
largest element. |
min |
Returns
smallest element. |
prod |
Product
of each column. |
reshape |
Change
size |
size |
Computes
array size. |
sort |
Sorts
each column. |
sum |
Sums each
column. |
Special Matrices
eye |
Creates
an identity matrix. |
ones |
Creates
an array of ones. |
zeros |
Creates
an array of zeros. |
Matrix Arithmetic
cross |
Computes
cross products. |
dot |
Computes
dot products. |
Matrix Commands for Solving Linear Equations
det |
Computes
determinant of an array. |
inv |
Computes
inverse of a matrix. |
pinv |
Computes
pseudoinverse of a matrix. |
rank |
Computes
rank of a matrix. |
rref |
Computes
reduced row echelon form. |
Cell Array Functions
cell |
Creates
cell array. |
celldisp |
Displays
cell array. |
cellplot |
Displays
graphical representation of cell array. |
num2cell |
Converts
numeric array to cell array. |
deal |
Matches
input and output lists. |
iscell |
Identifies
cell array. |
Structure Functions
fieldnames |
Returns
field names in a structure array. |
getfield |
Returns
field contents of a structure array. |
isfield |
Identifies
a structure array field. |
isstruct |
Identifies
a structure array. |
rmfield |
Removes a
field from a structure array. |
setfield |
Sets
contents of field. |
struct |
Creates
structure array. |
Plotting Commands
Basic xy Plotting Commands
axis |
Sets axis
limits. |
fplot |
Intelligent
plotting of functions. |
grid |
Displays
gridlines. |
plot |
Generates
xy plot. |
print |
Prints
plot or saves plot to a file |
title |
Puts text
at top of plot. |
xlabel |
Adds text
label to x-axis. |
ylabel |
Adds text
label to y-axis. |
Plot Enhancement Commands
axes |
Creates
axes objects. |
close |
Closes
the current plot. |
close all |
Closes
all plots. |
figure |
Opens a
new figure window. |
gtext |
Enables
label placement by mouse. |
hold |
Freezes
current plot. |
legend |
Legend
placement by mouse. |
refresh |
Redraws
current figure window. |
set |
Specifies
properties of objects such as axes. |
subplot |
Creates
plots in subwindows. |
text |
Places
string in figure. |
Specialized Plot Commands
bar |
Creates
bar chart. |
loglog |
Creates
log-log plot. |
polar |
Creates
polar plot. |
semilogx |
Creates
semilog plot (logarithmic abscissa). |
semilogy |
Creates
semilog plot (logarithmic ordinate). |
stairs |
Creates
stairs plot. |
stem |
Creates
stem plot. |
Colors, Symbols and Line Types
Color |
|
Symbol |
|
Line |
y |
yellow |
. |
point |
- |
solid |
m |
magenta |
o |
circle |
: |
dotted |
c |
cyan |
x |
x-mark |
-. |
dash
dotted |
r |
red |
+ |
plus |
-- |
dashed |
g |
green |
* |
star |
|
|
b |
blue |
d |
diamond |
w |
white |
v |
triangle
(down) |
k |
black |
^ |
triangle
(up) |
|
< |
triangle
(left) |
> |
triangle
(right) |
p |
pentagram |
h |
hexagram |
Three-Dimensional Plotting Commands
contour |
Creates
contour plot. |
mesh |
Creates
three-dimensional mesh surface plot. |
meshc |
Same as
mesh with contour plot underneath. |
meshz |
Same as
mesh with vertical lines underneath. |
plot3 |
Creates
three-dimensional plots from lines and points. |
surf |
Creates
shaded three-dimensional mesh surface plot. |
surfc |
Same as
surf with contour plot underneath. |
meshgrid |
Creates
rectangular grid. |
waterfall |
Same as
mesh with mesh lines in one direction. |
zlabel |
Adds text
label to z-axis. |
Histogram Functions
bar |
Creates a
bar chart. |
hist |
Aggregates
the data into equally spaced bins. |
histc |
Aggregates
the data into unequally spaced bins. |
Programming
Logical and Relational Operators
== |
Relational
operator: equal to. |
~= |
Relational
operator: not equal to. |
< |
Relational
operator: less than. |
<= |
Relational
operator: less than or equal to. |
> |
Relational
operator: greater than. |
>= |
Relational
operator: greater than or equal to. |
& |
Logical
operator: AND. |
| |
Logical
operator: OR. |
~ |
Logical
operator: NOT. |
xor |
Logical
operator: EXCLUSIVE OR. |
Program Flow Control
break |
Terminates
execution of a loop. |
case |
Provides
alternate execution paths within switch structure. |
else |
Delineates
alternate block of statements. |
elseif |
Conditionally
executes statements. |
end |
Terminates
for, while, and if statements. |
error |
Display
error messages. |
for |
Repeats
statements a specific number of times |
if |
Executes
statements conditionally. |
otherwise |
Default
part of switch statement. |
return |
Return to
the invoking function. |
switch |
Directs
program execution by comparing point with case expressions. |
warning |
Display a
warning message. |
while |
Repeats
statements an indefinite number of times. |
Logical Functions
any |
True if
any elements are nonzero. |
all |
True if
all elements are nonzero. |
find |
Finds
indices of nonzero elements. |
finite |
True if
elements are finite. |
isnan |
True if
elements are undefined. |
isinf |
True if
elements are infinite. |
isempty |
True if
matrix is empty. |
isreal |
True if
all elements are real. |
M-Files
eval |
Interpret
strings containing Matlab expressions. |
feval |
Function
evaluation. |
function |
Creates a
user-defined function M-file. |
global |
Define
global variables. |
nargin |
Number of
function input arguments. |
nargout |
Number of
function output arguments. |
varargin |
Cell array that will allow for a variable number of function inputs. |
nargout |
Cell array that will allow for a variable number of function outputs. |
script |
Script
M-files |
Timing
cputime |
CPU time
in seconds. |
clock |
Current
date and time as date vector. |
tic, toc |
Start,
stop a stopwatch timer. |
Mathematical Functions
Exponential and Logarithmic Functions
exp(x) | Exponential; ex |
log(x) | Natural logarithm; ln(x) |
log10(x) | Common (base 10) logarithm; log(x) = log10(x) |
sqrt(x) | Square root
|
Trigonometric Functions
Note: these functions assume/return angle values in radians.
There are similar functions (suffixed with a d) that work in degrees.
See the help file for details.
acos(x) |
Inverse
cosine; arcos x = cos –1 (x). |
acot(x) |
Inverse
cotangent; arccot x = cot –1(x). |
acsc(x) |
Inverse
cosecant; arcs x = csc –1 (x). |
asec(x) |
Inverse
secant; arcsec x = sec –1 (x). |
asin(x) |
Inverse
sine; arcsin x = sin –1 (x). |
atan(x) |
Inverse
tangent; arctan x = tan –1 (x). |
atan2(y,x) |
Four-quadrant
inverse tangent. |
cos(x) |
Cosine;
cos(x). |
cot(x) |
Cotangent;
cot(x). |
csc(x) |
Cosecant;
csc(x). |
sec(x) |
Secant;
sec(x). |
sin(x) |
Sine;
sin(x). |
tan(x) |
Tangent;
tan(x). |
Hyperbolic Functions
acosh(x) |
Inverse
hyperbolic cosine; cosh –1 (x). |
acoth(x) |
Inverse
hyperbolic cotangent; coth –1 (x). |
acsch(x) |
Inverse
hyperbolic cosecant; csch –1 (x). |
asech(x) |
Inverse
hyperbolic secant; sech –1 (x). |
asinh(x) |
Inverse
hyperbolic sine; sinh –1 (x). |
atanh(x) |
Inverse
hyperbolic tangent; tanh –1 (x). |
cosh(x) |
Hyperbolic
cosine; cosh(x). |
coth(x) |
Hyperbolic
cotangent; cosh(x)/sinh(x). |
csch(x) |
Hyperbolic
cosecant; 1/sinh(x). |
sech(x) |
Hyperbolic
secant; 1/cosh(x). |
sinh(x) |
Hyperbolic
sine; sinh(x). |
tanh(x) |
Hyperbolic
tangent; sinh(x)/cosh(x). |
Complex Functions
abs(x) |
Absolute
value; |x|. |
angle(x) |
Angle of
a complex number x. |
conj(x) |
Complex
conjugate of x. |
imag(x) |
Imaginary
part of a complex number x. |
real(x) |
Real part
of a complex number x. |
Statistical Functions
erf(x) |
Computes
the error function erf (x). |
mean |
Calculates
the average. |
median |
Calculates
the median. |
std |
Calculates
the standard deviation. |
Random Number Functions
rand |
Generates
uniformly distributed random numbers between 0 and 1. |
randn |
Generates
normally distributed random numbers. |
Numeric Functions
ceil |
Rounds to
the nearest integer toward •. |
fix |
Rounds to
the nearest integer toward zero. |
floor |
Rounds to
the nearest integer toward - •. |
round |
Rounds
towards the nearest integer. |
sign |
Signum
function. |
String Functions
findstr |
Finds
occurrences of a string. |
strcmp |
Compares
strings. |
char |
Creates
character string array |
Numerical Methods
Polynomial and Regression Functions
conv |
Computes
product of two polynomials |
deconv |
Computes
ratio of polynomials. |
eig |
Computes
the eigenvalues of a matrix. |
poly |
Computes
polynomial from roots. |
polyfit |
Fits a
polynomial to data. |
polyval |
Evaluates
polynomial and generates error estimates. |
roots |
Computes
polynomial roots. |
Interpolation Functions
interp1 |
Linear
and cubic-spline interpolations of a function of one variable. |
interp2 |
Linear
interpolation of a function of two variables. |
spline |
Cubic-spline
interpolation. |
unmkpp |
Computes
the coefficients of cubic-spine polynomials. |
Root Finding and Minimization
fmin |
Finds
minimum of single-variable function. |
fmins |
Finds
minimum of multivariable function. |
fzero |
Finds
zero of single-variable function. |
Numerical Integration Functions
quad |
Numerical
integration with adaptive Simpson’s rule. |
quadl |
Numerical
integration with adaptive Lobatto quadrature. |
trapz |
Numerical
integration with the trapezoidal rule. |
Numerical Differentiation Functions
diff(x) |
Computes
the difference between adjacent elements in the vector x. |
polyder |
Differentiates
a polynomial, a polynomial product, or a polynomial quotient. |
ODE Solvers
ode23 |
Nonstiff,
low-order solver. |
ode45 |
Nonstiff,
medium-order solver. |
ode113 |
Nonstiff,
variable-order solver. |
ode23s |
Stiff,
low-order. |
ode23t |
Moderately
stiff, trapezoidal rule solver. |
ode23b |
Stiff,
low-order solver. |
ode15s |
Stiff,
variable-order solver. |
odeset |
Creates
integrator options structure for ODE solvers. |
Predefined Input Functions
gensig |
Generates
a periodic sine, square, or pulse input. |
sawtooth |
Generates
a periodic sawtooth input. |
square |
Generates
a square wave input. |
stepfun |
Generates
a step function input. |
Symbolic Math Toolbox
Functions for Creating and Evaluating Symbolic Expressions
class |
Returns
the class of an expression. |
digits |
Sets the
number of decimal digits used to do variable precision arithmetic. |
double |
Converts
an expression to numeric form. |
ezplot |
Generates
a plot of a symbolic expression. |
findsym |
Finds the
symbolic variables in a symbolic expression. |
numden |
Returns
the numerator and denominator of an expression. |
sym |
Creates a
symbolic variable. |
syms |
Creates
one or more symbolic variables. |
vpa |
Sets the
number of digits used to evaluate expressions. |
Functions for Manipulating Symbolic Expressions
collect |
Collects
coefficients of like powers in an expression. |
expand |
Expands
an expression by carrying out jpowers. |
factor |
Factors
an expression. |
poly2sym |
Converts
a polynomial coefficient vector to a symbolic polynomial. |
pretty |
Displays
an expression in a form that resembles typeset mathematics. |
simple |
Searches
for the shortest form of an expression. |
simplify |
Simplifies
an expression using Maple’s simplification rules. |
subs |
Substitutes
variables or expressions. |
sym2poly |
Converts
an expression to a polynomial coefficient vector. |
Symbolic Calculus Functions
diff |
Returns
the derivative of an expression. |
Dirac |
Dirac
delta function (unit impulse). |
Heaviside |
Heaviside
function (unit step). |
int |
Returns
the integral of an expression. |
limit |
Returns
the limit of an expression. |
symsum |
Returns
the symbolic summation of an expression. |
taylor |
Returns
the Taylor series of a function. |
Symbolic Solution of Algebraic and Transcendental Equations
solve |
Solves
symbolic equations. |
Symbolic Solution of Differential Equations
dsolve |
Returns a
symbolic solution of a differential equation or set of equations. |
Laplace Transform Functions
ilaplace |
Returns
the inverse Laplace transform. |
laplace |
Returns
the Laplace transform. |
Symbolic Linear Algebra Functions
det |
Returns
the determinant of a matrix. |
eig |
Returns
the eigenvalues (characteristic roots) of a matrix. |
inv |
Returns
the inverse of a matrix. |
poly |
Returns
the characteristic polynomial of a matrix. |