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 |