Plotting - Citadel
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Transcript Plotting - Citadel
Plotting
ELEC 206
Computer Applications for
Electrical Engineers
Dr. Ron Hayne
Two-Dimensional Plots
x-y Plot
x-axis
independent variable
y-axis
dependent variable
x = [1:10];
y = [58.5, 63.6, 64.2, 67.3, 71.5, ...
88.3, 90.1, 90.6, 89.5, 90.4];
plot(x,y)
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Basic Plotting
Labels
plot(x,y)
title('Lab 1')
xlabel('Voltage')
ylabel('Current')
grid on
plot(x,y), title('Lab 1'),
xlabel('Voltage'), ylabel('Current'),
grid on
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Basic Plotting
Figure Control
pause, pause(n)
figure, figure(n)
Multiple Plots
hold on, hold off
plot(X, Y, W, Z)
plotyy(X, Y, W, Z)
Subplots
subplot(m,n,p)
m-by-n grid
pth window
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Basic Plotting
Style Control
Line Type
solid
Indicator
-
dotted
Point Type
point
Indicator
.
Color
blue
Indicator
b
:
circle
o
green
g
dash-dot
-.
x-mark
x
red
r
dashed
--
plus
+
black
k
Axis Scaling
axis, axis(v)
v = [xmin,xmax,ymin,ymax]
Annotation
legend('string1', 'string2')
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Example
figure(3)
x = 0:pi/100:2*pi;
y1 = cos(4*x);
y2 = sin(x);
plot(x,y1,':r',x,y2,'--b')
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Other Plots
Polar Plots
polar(theta,rho)
Example
figure(4)
polar(x,y1,':r')
hold on
polar(x,y2,'--b')
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Other Plots
Logarithmic Plots
semilogx(x,y)
semilogy(x,y)
loglog(x,y)
Bar Graphs and Pie Charts
bar(x), barh(x)
bar3(x), bar3h(x)
pie(x), pie3(x)
Histograms
hist(x), hist(x,bins)
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Problem Solving Applied
UDF Engine Performance
Problem Statement
Calculate the velocity and acceleration using a script
M-file
Input/Output Description
Start Time = 0 sec
Velocity
Final Time = 120 sec
Acceleration
Time Increment = 10 sec
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Problem Solving Applied
Hand Example
velocity = 0.00001 time3 - 0.00488 time2 +
0.75795 time + 181.3566
acceleration = 3 - 0.000062 velocity2
For time = 100 sec
velocity = 218.35 m/sec
acceleration = 0.04404 m/sec2
Algorithm Development (outline)
Define time matrix
Calculate velocity and acceleration
Output results in table
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MATLAB Solution
clear, clc
%Example 4.3
%These commands generate velocity and acceleration
%values for a UDF aircraft test
%Define the time matrix
time = 0:10:120;
%Calculate the velocity matrix
velocity = 0.00001*time.^3 - 0.00488*time.^2 ...
+ 0.75795*time + 181.3566;
%Use calculated velocities to find the acceleration
acceleration = 3 - 6.2e-5*velocity.^2;
%Present the results in a table
[time', velocity', acceleration']
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Table Output
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Plotting Results
%Create x-y plots
plot(time,velocity)
title('Velocity of a UDF Aircraft')
xlabel('time, seconds')
ylabel('velocity, meters/sec')
grid on
%
figure(2)
plot(time, acceleration,':k')
title('Acceleration of a UDF Aircraft')
xlabel('time, seconds')
ylabel('acceleration, meters/sec^2')
grid on
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Plotting Results
%Use plotyy to create a scale on each side of plot
figure(3)
plotyy(time, velocity,time,acceleration)
title('UDF Aircraft Performance')
xlabel('time, seconds')
ylabel('velocity, meters/sec')
grid on
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Three-Dimensional Plotting
3-D Line Plot
plot3(x,y,z)
Surface Plots
mesh(z), mesh(x,y,z)
surf(z), mesh(x,y,z)
shading, colormap
Contour Plots
contour(z), contour(x,y,z)
surfc(z), surfc(x,y,z)
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Example
figure(5)
z=peaks(25);
surfc(z)
colormap(jet)
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More Plotting
Creating Plots from the Workspace Window
Plotting Icon
Editing Plots from the Menu Bar
Copy Figure
10
5
0
-5
-10
30
25
20
20
15
10
10
0
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Summary
Two-Dimensional Plots
Problem Solving Applied
Three-Dimensional Plots
End of Chapter Summary
MATLAB Summary
Characters, Commands and Functions
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Test #3 Review
MATLAB Environment
MATLAB Windows
Scalar Operations
Array Operations
Saving Your Work
Predefined MATLAB Functions
MATLAB Functions
Manipulating Matrices
Special Values and Functions
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Test #3 Review
Plotting
Two-Dimensional Plots
Three-Dimensional Plots
Applications
Data Analysis
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