Links
Matlab Primer Matlab Primer (1) Matlab Primer (2) Matlab Primer (3)
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MATLAB Quick Reference
Below is a basic list of the built-in MATLAB commands that we will use for this course. It is by no means complete, but should help in getting us started. For more detailed help and/or examples, please consult one of help methods outlined below.
Also see the MATLAB Primer, see the side bar.
In the following chart, 'a' and 'b' refer specifically to numbers while 'x' and 'y' refer to either numbers or lists of numbers of the same length. In particular, to eliminate any redundancy, if a specific operation works for lists, the exact same usage works a single number.
In addition, if an operation/function acts on a list, then the operation is performed component-wise. For example, under usages for the operation of multiplication is listed a*x and x.*y (note the use of ".*" when multiplying lists). This means that if we let a=5, x=[1,2,3,4] and y=[2,3,5,7] then a*x=[5,10,15,20] and x.*y=[2,6,15,28].
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NAME |
USAGE |
COMMENTS |
HELP |
command-line help |
help topic |
Gives help/examples on the specified topic |
help window |
helpwin |
Opens a help window |
on-line help |
helpdesk |
Opens an on-line help window |
CONSTANTS
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Pi |
pi |
3.14159... |
e |
exp(1) |
2.71828... |
i |
i, j |
sqrt(-1) |
OPERATIONS
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addition |
x+y |
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subtraction |
x-y |
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multiplication |
a*x, x.*y |
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division |
x/a, x./y |
a\x (y.\x) is equivalent to x/a (x./y) |
powers |
a^b, a.^x, x.^a, x.^y | |
BASIC FUNCTIONS
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square root |
sqrt(x) |
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sine |
sin(x) |
csc, sec, cot, acsc, asec, acot, sinh, cosh, tanh, csch, sech, coth, asinh, acosh, atanh, acsch, asech, acoth are also defined. |
cosine |
cos(x) |
tangent |
tan(x) |
inverse sine |
asin(x) |
inverse cosine |
acos(x) |
inverse tangent |
atan(x) |
exponential |
exp(x) |
ex
|
logarithm |
log(x) |
natural logarithm |
factorial |
gamma(n+1) |
n! |
summation |
sum(x) |
the sum of the elements of x |
product |
prod(x) |
the product of the elements of x |
partial summation |
cumsum(x) |
the partial sums of the elements of x |
partial product |
cumprod(x) |
the partial products of the elements of x |
PLOTTING
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ezplot |
ezplot(f) ezplot(f,xmin,xmax) |
f is a string or a symbolic object |
plot |
plot(y) plot(x,y) plot(x,y,s) |
s is a string that specifies the plot options of color and style. y is the list of y-coordinates to plot and x is the corresponding x-coordinates |
fplot |
fplot(f,lims) |
f is a string and lims=[xmin xmax] or [xmin xmax ymin ymax] |
new plot |
figure |
Creates a new blank graph on which to plot. The old plot will remain and can be edited by simply selecting it and then typing the desired commands into |
MATLAB.
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hold on |
hold on |
Enables multiple plots on same graph |
hold off |
hold off |
Disables multiple plots on same graph |
plot title |
title('text') |
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label x-axis |
xlabel('text') |
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label y-axis |
ylabel('text') |
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label plot |
gtext('text') |
Used to label any desired part of a plot |
CREATING NEW FUNCTIONS
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inline |
f=inline('f',n) |
f is a function of n. |
M-files |
- |
See p.41 of 'ODEs using Matlab' |
SYMBOLIC TOOLBOX
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define variable |
syms X |
Defines X to be a symbolic variable. Must define a symbolic variable before using the following functions. |
taylor series |
taylor(f) taylor(f,a) taylor(f,n) taylor(f,n,a) |
The output is a symbolic object that represents the taylor polynomial of f of degree n-1 centered at a. |
to string |
char(f) |
Converts a symbolic object into a string. Useful for plotting symbolic objects with fplot |
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