A Concise Introduction to MATLAB – William J. Palm III
Chapter 5 Advanced Plotting and Model Building
5.1 xy Plotting Functions
Plots of complex Numbers
>> z=0.1+0.9i;
>> n=[0:0.01:10];
>> plot(z.^n),xlabel('Real'),ylabel('Imaginary')
The Function Plot Command fplot
>> f=@(x) (cos(tan(x))-tan(sin(x)));
>> fplot(f,[1 2])
Plotting Polynomials
>> x=[-6:0.01:6];
>> p=[3,2,-100,2,-7,90];
>> plot(x,polyval(p,x)),xlabel('x'),ylabel('p')
T5.1-1 Plot the equation y  0.4 1.8 x for 0  x  35 and 0  y  3.5
>> x=0:0.01:35;
>> y=0.4.*sqrt(1.8*x);
>>plot(x,y),xlabel('x'),ylabel('y'),title('y=0.4sqrt(1.8x)'),axi
s([0 35 0 35]),grid
>> x=0:0.01:35;
>> y=0.4.*sqrt(1.8*x);
>> plot(x,y),xlabel('x'),ylabel('y'),title('Function y'),grid
T 5.1-2 use fplot command to plot the function
tan(cos( x))  sin(tan( x)) for 0  x  2
>> f=@(x)(tan(cos(x))-sin(tan(x)));
>> fplot(f,[0 2*pi])
T5.1-3 Plot (0.2  0.8i)n for 0  n  20
>> x=0.2+0.8i;
>> n=0:0.001:20;
>> plot(x.^n),xlabel('Real'),ylabel('Imaginary'),title('Complex
Plot'),axis([0 20 0 x.^n])
5.2 Additional Commands and Plot types – Subplots
>> cd F:\MATLAB_PRA
>> edit
x=[0:0.01:5];
y=exp(-1.2*x).*sin(10*x+5);
subplot(1,2,1),plot(x,y),xlabel('x'),ylabel('y'),axis([0 5 -1 1])
x=[-6:0.01:6];
y=abs(x.^3-100);
subplot(1,2,2),plot(x,y),xlabel('x'),ylabel('y'),axis([-6 6 0 350])
Ctrl+Ssubplt1
To execute
>> suplt1
T5.2-1
>> cd F:\MATLAB_PRA
>> edit
t=0:0.001:8;
v=-8:0.001:8;
z=exp(-0.5*t).*cos(20*t-6);
u=6.*log10(v.^2+20);
subplot(2,1,1),plot(t,z),xlabel('x'),ylabel('z'),title('Graph1'),grid
subplot(2,1,2),plot(v,u),xlabel('x'),ylabel('u'),title('Graph2'),grid
Ctrl+Ssubplt2
To execute
>> suplt2
Labeling Curves and Data
>> cd F:\MATLAB_PRA
>> x=[0:0.01:2];
>> y=sinh(x);
>> z=tanh(x);
>> plot(x,y,x,z,'--'),xlabel('x'),ylabel('sinh and
tanh'),legend('sinh(x)','tanh(x)')
The hold command
>> x=[-1:0.01:1];
>> n=[0:0.01:10];
>> y1=3+exp(-x).*sin(6*x);
>> y2=4+exp(-x).*cos(6*x);z=0.1+0.9i;
>>
plot(y1,y2),xlabel('x'),ylabel('y'),hold,plot(z.^n),title('Two
plots'),gtext('y2,y1 plot'),gtext('Complex plots')
Current plot held
T5.2-2
>> x=[0,1,2,3,4,5];
>> y1=[11,13,8,7,5,9];
>> y2=[2,4,5,3,2,4];
>> plot(x,y1,'-o',x,y2,'-d'),xlabel('x'),ylabel('y1&Y2'),title('Two
curves'),legend('y1','y2'),grid
T5.2-3
>> x=0:0.001:2;
>> y1=cosh(x);
>> y2=0.5*exp(x);
>> plot(x,y1,x,y2,'--'),xlabel('x'),ylabel('y1&y2'),title('Two
Curves'),legend('cosh(x)','0.5.e^{x}'),grid
T5.2-4
>> x=0:0.001:2;
>> y1=sinh(x);
>> y2=0.5*exp(-x);
>>
plot(x,y1,'r',x,y2,'k'),ylabel('x'),ylabel('y1&y2'),title('Two
Curves'),title('0.5.e^{x}'),text(1,8,'exp
curve'),gtext('sinhx'),grid
T5.2-5
>> x=0:0.001:1;
>> y1=sin(x);
>> y2=x-(x.^3./3);
>>
plot(x,y1),xlabel('x'),ylabel('y1,y2'),hold,plot(x,y2,'k'),gtext
('y1'),gtext('y2'),title('Holding Graphs'),grid
Current plot held
Log log plot of the function
y
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100(1  0.01x 2  0.02 x 2
(1  x 2 )2  0.1x 2
x=logspace(-1,2,500);
u=x.^2;
num=100*(1-0.01*u).^2+0.02*u;
den=(1-u).^2+0.1*u;
y=sqrt(num./den);
loglog(x,y),xlabel('x'),ylabel('y')
Script
file:Hermite
Contents
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0.1  x  100
Define the range
Hermite family
Plots
Define the range
t=-5:0.1:5;
Hermite family
H0=exp(-t.^2./4);
H1=t.*exp(-t.^2./4);
H2=(t.^2-1).*exp(-t.^2./4);
H3=(t.^4-6*t.^2+3).*exp(-t.^2./4);
Plots
plot(t,H0,'*:',t,H1,'d-.',t,H2,'h--',t,H3,'s-')
xlabel('t'),ylabel('Amplitude')
title('First four members of the Hermite family')
legend('Her 0','Her 1','Her 2','Her 3')
Script File:lagu.m
Contents
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Define time range
Laguerre polynomials
Plots
Define time range
t=0:0.1:15;
Laguerre polynomials
L0=exp(-t./2);
L1=(1-t).*t.*exp(-t./2);
L2=(1-2.*t+0.5.*t.^2).*exp(-t./2);
L3=(t.^3-3.*t).*exp(-t.^2/.4);
Plots
plot(t,L0,'*:',t,L1,'d-.',t,L2,'s-',t,L3,'p:')
xlabel('t'),ylabel('Amplitude')
title('Members of Laguerre
family')
legend('Lag 0','Lag 1','Lag 2','Lag 3')
Published with MATLAB® R2018a
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x1=0:0.001:100;
y1=sin(x1);
y2=tan(x1);
plotyy(x1,y1,x1,y2)
Plotting Orbits
r
p
1   cos 
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p=2;
e=0.5;
theta=[0:pi/90:2*pi];
r=p./(1-e.*cos(theta));
polar(theta,r),title('Orbital Eccentricity=0.5')
>> x=0:0.001:1.5;
>> y1=2.*x.^(-0.5);
>> y2=10.^(1-x);
>>
subplot(2,2,1),plot(x,y1,x,y2),xlabel('x'),ylabel('y'),gtext('Ex
ponential'),gtext('power'),subplot(2,2,2),semilogy(x,y1,x,y2),xl
abel('x'),ylabel('y'),gtext('Exponential'),gtext('power'),subplo
t(2,2,3),loglog(x,y1,x,y2),xlabel('x'),ylabel('y'),gtext('Expone
ntial'),gtext('power')
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>>
>>
>>
theta=[0:pi/90:4*pi];
a=2;
r=a.*theta;
polar(theta,r),title('Spiral of Archimedes')
>> contour(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z')
>> meshc(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z')
>> Z=X.*exp(-(X.^2+Y.^2));
>>
subplot(2,2,1),mesh(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z'),s
ubplot(2,2,2),meshc(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z'),s
ubplot(2,2,3),meshz(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z'),s
ubplot(2,2,4),waterfall(X,Y,Z),xlabel('x'),ylabel('y'),zlabel('z
')
Contents
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Script file:sincn.m
Plots
Script file:sincn.m
% Define time range
t=-5*pi:0.25:5*pi;
% sinc functions
s0=sin(t)./(pi.*t);
s1=sin(t-pi)./(pi*(t-pi));
s2=sin(t-2*pi)./(pi*(t-2*pi));
s3=sin(t-3*pi)./(pi*(t-3*pi));
Plots
plot(t,s0,'*:',t,s1,'d-.',t,s2,'h--',t,s3,'s-')
xlabel('t'),ylabel('Amplitude')
title('Members of sinc family')
legend('sinc 0','sinc 1','sinc 2','sinc 3')
>> image(magic(10)),title('Image pattern of Magic Square')