Basics of MATLAB and Beyond

More documents

Recommendations

Info

$Algoritmos de para calcular la dimensiÃ³n fractal de seÃ±ales 1D La ...$

eval(str)v =1 2 3 4 5The eval(str) statement acts just as if we had typed v = 1:5 at thecommand line. To suppress the output we need to add a semicoloncharacter to the end of the string:>> str = ’v = 1:5;’str =v = 1:5;>> eval(str)The eval command now produces no output, while still defining thevariable v. To take another example, let us suppose we want to define aset of vectors v i =1, 2,...i for i =1, 2 ...10. At the command line wecould type:v1 = 1;v2 = 1:2;v3= 1:3;and so on. The eval command provides a neat solution:>> clear>> for i = 1:10str = [’v’ int2str(i) ’ = 1:i;’];eval(str)endThis has generated the variables v1, ..., v10, with the appropriate elements:>> whosName Size Bytes Classi 1x1 8 double arraystr 1x10 20 char arrayv1 1x1 8 double arrayv10 1x10 80 double arrayv2 1x2 16 double arrayv31x3 24 double arrayv4 1x4 32 double arrayv5 1x5 40 double arrayv6 1x6 48 double arrayv7 1x7 56 double arrayv8 1x8 64 double arrayv9 1x9 72 double arrayGrand total is 66 elements using 468 bytesc○ 2000 by CRC Press LLC
v6v6 =1 2 3 4 5 6The feval FunctionThe feval command is like eval, except that it is used for evaluatingnamed functions. An example would be:str = ’sin’;t = linspace(0,2*pi);q = feval(str,t);plt(t,q)If str is a string containing the name of a function, then y =feval(str,x) evaluates that function for the input argument x.Another example defines data for plotting by looping over the trigonometricfunctions sin, cos, and tan contained within a single matrix ofcharacters (the command zeroaxes is part of the companion softwareto this book):str = [’sin’;’cos’;’tan’];for i = 1:3q(i,:) = feval(str(i,:),t);endclfplt(t,q)axis([0 2*pi -6 6])zeroaxesInline ObjectsInline objects allow you to store a function as a string and use it muchas you would write it symbolically. This, for example, is how to definethe parabola f(x) =(x + 1)(x − 1):>> f = inline(’(x + 1).*(x - 1)’)f =Inline function:f(x) = (x + 1).*(x - 1)We can now evaluate f(3) by typing:>> f(3)ans =8c○ 2000 by CRC Press LLC
Page 2 and 3:
BASICS OFMATLAB®and Beyondc○ 200
Page 4 and 5:
Library of Congress Cataloging-in-P
Page 6 and 7:
typing pwd (print working directory
Page 8 and 9:
ContentsIBasics of MATLAB1 First St
Page 10 and 11:
20 Time-Frequency Analysis21 Line A
Page 12 and 13:
39Answers to Exercises (Part I)40 A
Page 14 and 15:
Set → Getting Started with MATLAB
Page 16 and 17:
1.5 The Colon OperatorTo generate a
Page 18 and 19:
matlab will recall the last command
Page 20 and 21:
a = zeros(2,3)a =0 0 00 0 0>> b = o
Page 22 and 23:
[a a(a)]ans =1 2 3 1 4 74 5 6 2 5 8
Page 24 and 25:
a + bans =11 3344 6677 993.8 Transp
Page 26 and 27:
4.2 Adding PlotsWhen you issue a pl
Page 28 and 29:
x = [[1 2 3 4]’ [2 3 4 5]’ [3 4
Page 30 and 31:
4.7 AxesSo far we have allowed matl
Page 32 and 33:
v =1122>> v*uans =1 2 0 11 2 0 12 4
Page 34 and 35:
max returns a vector containing the
Page 36 and 37:
s = 100*spiral(3)s =700 800 900600
Page 38 and 39:
We can plot the surface z as a func
Page 40 and 41:
The contour function plots the cont
Page 42 and 43: m = gray(8);colormap(m)imagesc(1:10
Page 44 and 45: hold onplot3(x(ind),y(ind),z(ind),
Page 46 and 47: z = 5*ones(3,3)z =5 5 55 5 55 5 5>>
Page 48 and 49: contour(x,y,z,30);You may have noti
Page 50 and 51: variables that are local to themsel
Page 52 and 53: SwitchThe basic form of a switch st
Page 54 and 55: i =i =123136Vectorised Codematlab i
Page 56 and 57: 9.1 MATLAB FormatTo save all the va
Page 58 and 59: 11 StartupEach time you start matla
Page 60 and 61: Where p i is the population for yea
Page 62 and 63: NaNs by leaving them off the plot.
Page 64 and 65: clfpolar(t,gdb)In this case you mus
Page 66 and 67: -0.5000-0.3750-0.2500-0.125000.1250
Page 68 and 69: the periodograms of the blocks, and
Page 70 and 71: plot(y(1:1000))axis([0 1000 -5 5])z
Page 72 and 73: comet(x,y)(You can get a three-dime
Page 74 and 75: By clicking within the panner box a
Page 76 and 77: x = linspace(-1,1,8192);Fs = 1000;y
Page 78 and 79: 23.3 Graphical Object Hierarchymatl
Page 80 and 81: Now we need to get the handles of a
Page 82 and 83: Beyond the BasicsPreludeThis part o
Page 84 and 85: clfgplot(A,[x y])axis off(Try zoomi
Page 86 and 87: str =you’re the one>> str = ’
Page 88 and 89: strrep(str,’go’,’am’)ans =I
Page 90 and 91: ans =3.14159e+100Some additional te
Page 94 and 95: Inline objects, like every other ma
Page 96 and 97: a(1,1) = {[1 2 3]}a =[1x3double]or>
Page 98 and 99: t = {’help’ spiral(3) ; eye(2)
Page 101 and 102: meteo.Temperatureans =24ans =19.000
Page 103 and 104: 3 >> a = [1 2 ;4 5 6;7 8 9]a =1 2 3
Page 105 and 106: [x,y] = meshgrid(1:5,1:3)x =1 2 3 4
Page 107 and 108: ans(:,:,2) =999And to sum over “p
Page 109 and 110: An Application of RGB ImagesTo see
Page 111 and 112: You can see that over the 8 time st
Page 113 and 114: name>> staff(2,1,2).name(5:9)ans =B
Page 115 and 116: q =7 8 96 1 25 4 3>> save saved_dat
Page 117 and 118: fid = fopen(’asc.dat’);The fope
Page 119 and 120: display and the enclosed area is th
Page 121 and 122: MarkerEdgeColor = auto(and so on)In
Page 123 and 124: text(-.7,f(-.7),’f(X)’)But we h
Page 125 and 126: plt(x,f(x/2),’--’)Let us try ca
Page 127 and 128: Example: findobjThe findobj command
Page 129 and 130: 3. Add the property you want to set
Page 131 and 132: is numbered from top to bottom. The
Page 133 and 134: axis ijUsually images like this do
Page 135 and 136: 32.2 Tick Marks and Labelsmatlab’
Page 137 and 138: clfaxes(’pos’,[.2 .1 .7 .4])x =
Page 139 and 140: property to [0 top] in the call to
Page 141 and 142: object’s HorizontalAlignment and
Page 143 and 144:
the required symbols. The m-file ti
Page 145 and 146:
1. Use graphical elements that serv
Page 147 and 148:
uicontrol(’Callback’,’ezplot(
Page 149 and 150:
uicontrol(’Pos’,[110 280 60 19]
Page 151 and 152:
’String’,’0.5’,’Style’,
Page 153 and 154:
function exradio(action)if nargin =
Page 155 and 156:
fail. One place to put variables th
Page 157 and 158:
34.7 Fast DrawingFor fast drawing o
Page 159 and 160:
controlled by guide and which are a
Page 161 and 162:
InvertHardcopy: [ {on} | off ]Paper
Page 163 and 164:
Another option is to use an image f
Page 165 and 166:
yur is the y coordinate of the uppe
Page 167 and 168:
\end{center}\caption{This is the fi
Page 169 and 170:
x 294x1 ...y 294x1 ...z 294x1 ...Gr
Page 171 and 172:
diagram. Such a triangular grid can
Page 173 and 174:
xt = x([1 9 10 1]);yt = y([1 9 10 1
Page 175 and 176:
x = [0 0 .5 0.5 .5 1 11 .5 .5 .5];y
Page 177 and 178:
fac2 = [1 2 61 6 31 4 61 6 5];The r
Page 179 and 180:
t = linspace(0,2*pi,20);x = cos(t);
Page 181 and 182:
N = 20;dt = 2*pi/N;t = 0:dt:(N-1)*d
Page 183 and 184:
colouring of the sphere itself. To
Page 185 and 186:
material dullThe default is materia
Page 187 and 188:
time taken by this routine to calcu
Page 189 and 190:
first row of a by taking the column
Page 191 and 192:
38.3 Debuggingmatlab has a suite of
Page 193 and 194:
10: y = linspace(ycentre - L,ycentr
Page 195 and 196:
We change variables:p ′ = C + Bx.
Page 197 and 198:
Exercise 6 (Page 59)You can generat
Page 199 and 200:
33 ! 36 $ 39 ’ 42 * 45 - 48 034 "
Page 201 and 202:
R = 1; N = 200;[x,y] = meshgrid(lin
Page 203 and 204:
(The plot might take a few seconds
Page 205:
% Reproduce the layers at the diffe
show all

Basics of MATLAB and Beyond

Create successful ePaper yourself

Delete template?

Save as template?