FAMU-FSU College of Engineering
Department of Electrical & Computer Engineering
EEL3002L - ECE Engineering Tools Laboratory
Lab Number 4
Plotting in MATLAB
Professor Bing W. Kwan
Revised: Spring 2024
EEL3002L
Lab #4
ECE Tools Lab
Lab Number 4
Plotting in MATLAB
Objective
The main goal of this lab is to enable the students to exploit MATALB plotting
functions to create basic but commonly used 2-D and 3-D graphs. The focus
is placed on (1) plotting 2-D line, bar, and area graphs; (2) plotting 3-D line,
mesh, and surface graphs; (3) editing graphs; and (4) printing and exporting
figures.
Outline
The scope of this lab is outlined as follows:
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
Overview of MATLAB plots
Two-dimensional (2-D) plotting functions
Three-dimensional (3-D) plotting functions
Multiple plots in one figure
Editing plots
Printing and exporting figures
In-lab experiments
Lab report
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Pre-lab Assignments
A. Reading
Lab #4 manual
Before coming to conduct the in-lab experiments, the students are required
to read and learn about the topics outlined above. This is a worthwhile exercise
that serves to complement their learning from the hands-on experiences
during the in-lab session. A comprehensive exposition of the subject matter is
included in this lab manual. In addition, the students are encouraged to seek
more detailed pertinent information from the following references:


Complete and extensive help files can be found by searching the online
documentation during an active MATLAB session.
Supplementary documents and resources supporting the use of MATLAB
are available at the MathWorks website: www.mathworks.com
Lecture Notes #1 & Lab #1 Manual
Learning MATLAB - Quick Start
Lecture Notes #2 & Lab #2 Manual
-- Notes: Using MATLAB for Linear Algebra Problems - Part I (A & B).
-- Manual: Using MATLAB for Linear Algebra Problems - Part I
Lecture Notes #3
Using MATLAB for Linear Algebra Problems - Part II
Lecture Notes #4
Plotting in MATLAB
(To be posted after the Tuesday lecture this coming week.)
B. Pre-lab exercises
Refer to Pre-lab Exercise Set #4, which is posted separately.
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4.1 Overview of MATLAB Plots
A variety of 2-D and 3-D MATLAB plots can be generated requiring very little,
if any, programming. In this lab, the students will learn how to create several
basic but commonly used plots. These include the line, bar, area, and surface
graphs. The basic procedures for editing, printing, and exporting graphs are
also explored.
In general, 2-D plotting functions are used to draw graphs for visualizing
functions of one variable having the form:
y  f ( x)
where
xmin  x  xmax
Similarly, 3-D plotting functions are used to draw line, mesh, and surface
graphs for viewing functions of two variables of the form:
z  f ( x , y)
where
xmin  x  xmax , ymin  y  ymax
4.2 Two-dimensional (2-D) Plotting Functions
A. Line graphs
ezplot
Two basic forms of syntax:
1. ezplot(fun_x, [xmin, xmax])
2. ezplot(fun_xy, [xmin, xmax, ymin, ymax])
The first form creates a 2-D line plot of y versus x according to the relation
explicitly defined by y = f(x). The character string fun_x is used to define the
function f(x). The second form creates a 2-D line plot of y versus x according
to the relation implicitly defined by the equation f(x, y) = 0. Similarly, the
character string fun_xy specifies the function f(x, y).
The array [xmin, xmax, ymin, ymax] specifies the ranges of x and y.
When the range specification is omitted, the default ranges are:
 2  x  2 ,  2  y  2
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Example
Use ezplot to draw the graph of y versus x defined explicitly by the relation:
y  f ( x)  x 2  3,  2  x  5
>> ezplot('x.^2- 3', [-2, 5]) % Vectorization is used.
>> grid on
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Example
Use ezplot to draw the graph of y versus x defined implicitly by the relation:
f ( x , y )  x 2  y 2  4  0,  4  x  4 ,  3  x  3
>> ezplot(@(x, y) (x.^2 + y.^2 - 4), [-4, 4, -3, 3])
>> grid on
Remarks
1. The MATLAB function handle @ (at operator) is used to define the
function f(x, y).
2. The function ezplot draws only one graph in the figure.
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fplot
This is another simple and easy to use MATLAB plotting function for drawing
the graph of a 2-D function with the following characteristics:
y  f ( x), xmin  x  xmax ,
ymin  y  ymax
Specifically, the range of values for both the x-axis and the y-axis may be
specified. Unlike ezplot, however, it is suited for drawing multiple graphs in
a single figure.
The syntax of fplot has the basic form: fplot(FUN, LIMS)
Remarks
1. FUN is the function to be plotted. It can be created by exploiting the
MATLAB function handle @ as illustrated below.
Example:
The 2-D function f ( x)  x1.5  7.5 may be created using the MATLAB function
handle as follows:
@(x)(x.^(1.5) - 7.5) % Specify f(x).
2. LIMS
= [xmin,xmax,ymin,ymax]: Specify the range for x-axis and y-axis.
= [xmin,xmax]: Specify range for x-axis only.
3. FUN can be extended to include multiple functions. This means several 2D functions sharing the same x-axis can be plotted in the same figure.
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Example
Use fplot to graph the following 2-D functions:
y1  tan ( x),
y 2  sin ( x),
y3  cos ( x), where  4  x, y1 , y 2 , y3 ,  4
The MATLAB commands are entered as follows:
>> fplot(@(x)[tan(x),sin(x),cos(x)], 4*pi*[-1 1 -1 1]);
>> grid on
The 3 functions are plotted in a single figure as shown below:
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plot
Basic syntax: plot(x1, y1, x2, y2,..., xn, yn)
This function plots n 2-D line graphs in a figure. Each line with distinct color
is plotted for the corresponding data set (xk, yk), namely xk versus yk,
where 1  k  n.
Example
>> x = [-pi : pi/100 : pi];
>> y = tan(sin(x)) - sin(tan(x));
>> plot(x, y), grid on
The above command sequence produces a single line plot with n = 1 as
shown in the following figure:
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plotyy
Basic syntax: plotyy(x1, y1, x2, y2)
This function is used to create 2-D line plots for y1 versus x1 with y-axis
labeling on the left and y2 versus x2 with y-axis labeling on the right.
Example
>>
y1
y2
>>
x = 0 : 0.01 : 20;
= 200*exp(-0.05*x).*sin(x);
= 0.8*exp(-0.5*x).*sin(10*x);
plotyy(x, y1, x, y2), grid on
The above command sequence produces the following graph:
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semilogx, semilogy
Basic syntax: semilogx(x1, y1, x2, y2,..., xn, yn)
semilogy(x1, y1, x2, y2,..., xn, yn)
The functions semilogx and semilogy plot the data on the logarithmic
scale for the x-axis and y-axis, respectively. More specifically,
 semilogx(x1,y1,...) plots all the data sets with x-axis on log scale.
 semilogy(x1,y1,...) plots all the data sets with y-axis on log scale.
Example
>> x = 0: 0.1 : 10;
>> semilogy(x,10.^(-x.*x/2)), grid on
The above command sequence produces the following graph:
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loglog
Basic syntax: loglog(x1, y1, x2, y2,..., xn, yn)
This function plots one line with distinct color for each data set (xk, yk),
where 1  k  n, on the logarithmic scale for both x-axis and y-axis.
Example
>> x = logspace(-1, 2, 50);
>> loglog(x, exp(-sqrt(x))), grid on
The above command sequence produces the following graph:
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stairs
Basic syntax: stairs(x, y)
This function plots the data in y at the locations specified in x. Stair-step
graphs are particularly useful for drawing time series of digitally sampled data.
Example
>> x = linspace(-2*pi, 2*pi, 40);
>> stairs(x, sin(x)), grid on
The above command sequence produces the following graph:
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polar
Basic syntax: polar(, )
This function plots data on the polar grid superimposed on the x-y plane. The
data points are specified in the polar coordinates stored in the array pair (,
). This means each element in specifies the distance from the origin along
the radial line that forms an angle specified by the corresponding element in
. The angles in are measured counterclockwise with respect to the x-axis.
Example
>> theta = 0: 0.01 : 2*pi;
>> rho = sin(2*theta).* cos(5*theta);
>> polar(theta, rho)
The above command sequence produces the following polar plot:
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B. Bar graphs
stem
Basic syntax: stem(x, y)
This function plots a 2-D graph displaying data as lines extending from a
baseline along the x-axis. Specifically, stems (vertical lines) with heights
proportional to the element values in y are extended from the x-axis locations
defined by the elements in x. By default, each stem is terminated in a circle.
Example
>> x = 0 : 10;
>> y = 0.75 * exp(-0.2*x);
>> stem(x, y), grid on
The above command sequence produces the following stem plot:
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hist
Basic syntax: hist(y, x)
This function plots the histogram showing how the values in a data set are
distributed. Specifically, the distribution is defined by the frequency counts of
the data values in y belonging to the bins (intervals) whose centers are
specified in x.
Example
>> x = -4 : 0.1 : 4;
>> y = randn(10000, 1);
>> hist(y, x), grid on
The above command sequence produces the following histogram:
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bar
Basic syntax: bar(x, ‘grouped’), bar(x, ‘stacked’)
This function displays the values in an (m  n) matrix x as vertical bars with
two basic display styles as described below:

Style ‘grouped’
The n values in each row of x are displayed as a group of n vertical bars
with proportional heights, thus resulting in m groups for x as a whole. The
bars corresponding to the same column have the same color.

Style ‘stacked’
The n values in each row of x are displayed as distinct colored segments
of proportional heights. These segments are stacked to form a single
vertical bar, thus resulting in m vertical bars for x as a whole. Hence, each
bar is multicolored with proportional heights. The elements from the same
column have the same color.
Example
>> y = 10*rand(3, 5)
y =
2.7603
1.6261
9.5974
6.7970
1.1900
3.4039
6.5510
4.9836
5.8527
>> figure(1)
>> bar(y, 'grouped'), grid on
>> figure(2)
>> bar(y, 'stacked'), grid on
2.2381
7.5127
2.5510
5.0596
6.9908
8.9090
The above command sequence produces bar graphs with two different styles
as shown in the following:
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‘grouped’style:
‘stacked’style:
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C. Area graphs
pie
Basic syntax: pie(x)
Extended syntax: pie(x, offset)
This function draws a pie chart using the data in x. The elements in x are
represented as slices with proportional areas in the pie chart. The optional
vector offset is used to select a slice drawn with an offset from the center
of the pie chart. Assigning a nonzero value to an element of offset will result
in the corresponding slice in the pie chart being drawn with an offset.
Example
>>
>>
>>
>>
x = [1 3 0.5 2.5 2];
figure(1), pie(x)
x_os = [0 1 0 0 0];
figure (2), pie(x, x_os)
The above command sequence produces a regular pie chart and one with an
offset slice.
1. Regular pie chart with no offset slice:
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2. Pie chart with one offset slice:
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4.3 Three-dimensional (3-D) Plotting Functions
The 3-D plotting functions are useful for viewing mathematical functions over
a rectangular region.
A. Line graphs
plot3
Basic syntax: plot3(x1, y1, z1,...)
This function displays a set of data points in the 3-D space. It is the analogue
of the 2-D plot function. A line is plotted through the data points, which are
defined by the corresponding elements of the triplet vector set (x1, y1,
z1), each having the same length. These vectors typically vary with a
common parameter t. In essence, plot3 produces multiple parameterized
curves in the 3-D space when multiple triple vector sets are provided.
Example
>> t = 0: pi/100 : 4*pi;
>> plot3(sin(0.75*t), cos(t), t)
>> grid on
The above command sequence produces the following helix-like curve:
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B. Mesh graphs
mesh
Basic syntax: mesh(x, y, z)
This function creates a wireframe surface specified by the elements of x, y,
and z, where z = f(x, y). A wireframe surface is a collection of surface
patches that are formed by straight lines connecting the grid points z(m, n)
on the surface. Specifically, a surface grid point z(m, n) is determined by
the 2-D coordinate pair (x(n), y(m)) of the rectangular grid defined by
the coordinate vectors x_c and y_c. The wireframe line color is proportional
to the surface height measured by z(m, n).
Example
>>
>>
>>
>>
x_c = [2 : 0.2 : 4]; y_c = [1 : 0.2 : 3];
[x, y] = meshgrid(x_c, y_c);
z = (x - 3).^2 - (y - 2).^2;
mesh(x, y, z)
The above command sequence produces the following wireframe surface:
Surface grid points
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C. Surface graphs
surf
Basic syntax: surf(x, y, z)
This function plots a surface of the form z = f(x, y) in essentially the
same manner as mesh does. The only distinction is mesh displays a wireframe
surface but only colors the connecting lines, whereas surf displays the
connecting lines in black and the surface patches in color. The color for each
patch is proportional to the surface height.
Example
>>
>>
>>
>>
[x, y] = meshgrid([-2 : 0.2 : 2]);
z = -x.*y.*exp(-2*(x.*x + y.*y));
surf(x, y, z)
xlabel('x'), ylabel('y')
The above command sequence produces the following surface plot:
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4.4 Multiple Plots in One Figure
The subplot command displays multiple plots in the same figure window. To
partition the figure window into an (m n) matrix of small subplots, one enters
the command:
>> subplot(m, n, k)
The index k, for 1  k  mn, is used to identify the subplots in the matrix
structure. It also specifies the position of a subplot in the (m n) matrix. The
following figure illustrates the arrangement of 12 subplots in the (3  4)
matrix structure (namely m = 3, n = 4):
Subplot Subplot Subplot Subplot
1
2
3
4
Subplot Subplot Subplot Subplot
5
6
7
8
Subplot Subplot Subplot Subplot
9
10
11
12
Observe that the subplots are arranged in the matrix row-wise, starting from
the top left, in accordance with the position index k in the ascending order.
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Example
>>
>>
>>
>>
>>
>>
t = 0 : pi/10 : 2*pi;
[x, y, z] = cylinder(4*cos(t));
subplot(2, 2, 1); mesh(x)
subplot(2, 2, 2); mesh(y)
subplot(2, 2, 3); mesh(z)
subplot(2, 2, 4); mesh(x, y, z)
The above command sequence results in 4 subplots in a single figure arranged
in the (2  2) matrix pattern as shown below:
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4.5 Editing Plots
To ensure readability, MATLAB graphs are formatted such that (a) the axes
have proper scales and tick marks, and (b) the lines have distinct styles and
colors. Nevertheless, the default format can be edited to add descriptive
labels, titles, legends, and other annotations to enhance the visualization of
the data.
MATLAB Plots can be edited using two approaches as described in the
following.

Using MATLAB functions at the command line or in an M-file
This approach is not suited for this introductory lab as it requires more
programming experience and advanced knowledge about MATLAB.

Using the interactive plot-edit mode
The MATLAB figure window supports a point-and-click editing mode. A user
can enter this plot-edit mode to perform basic editing tasks which
include selecting, cutting, copying, pasting, moving, and resizing objects.
Other plot properties can also be modified.
Two simple ways to enter the plot-edit mode are as follows:
1. Select the Edit Plot option on the figure window Tools menu.
2. Click the selection button in the figure window toolbar as depicted below.
Click the arrow button to enable the
edit mode.
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4.6 Printing and Exporting Figures
MATLAB figures can be included in a variety of applications such as word
processing, slide presentation, modification by a graphics program, and so on.
Hence, exporting MATLAB figures in appropriate graphic formats supported by
the target applications is essential. The basic means of exporting and printing
figures generated in MATLAB are explored in this section.
Exporting and printing figures often involve the graphical-user-interface (GUI)
features which are initiated via the menu-bar in the MATLAB figure window
depicted below.
A. Using Print Preview
It is good practice to preview the figure before printing or exporting. The
Print Preview GUI dialog box allows a user to preview the figure before
printing or exporting. In addition, the figure characteristics and properties can
be set or adjusted. The preview dialog box can be opened using the following
select-click sequence:
File >> Print Preview
B. Printing figures
The basic options for printing a MATLAB figure are noted in the following.
Printing on Microsoft Windows platforms
MATLAB printing on Windows platforms uses the standard Windows Print
dialog box. To open the Windows Print dialog box in an active figure window,
one applies the following select-click sequence:
File >> Print
Note that clicking on the Print button in the Print Preview dialog box
serves the same purpose.
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To print the current active figure on the default printer, one simply enters the
command:
>> print
Printing to a file
One has the option of printing a figure to a file instead of sending it to a
printer. In this case, the two basic options are as follows:

Printing to a file on Windows platforms
The standard Windows procedure for printing the current figure to a file
involves the steps listed below:
Step 1: Select and click File >> Print.
Step 2: Select the check box Print to file.
Step 3: Click the OK button, and then specify the output filename.

Printing to a file using MATLAB commands
One uses the print function to print from the MATLAB command line or
from a program. A generic command line is featured below:
>> print –dgraphic_format figure_name
This will result in the current active figure to be exported as a graphics file
having format graphic_format and filename figure_name. MATLAB
selects the filename extension if it is not specified.
The following two examples serve to illustrate the basic elements involved
in the procedure.
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Example
To save the current figure as a TIFF file named saddle with a resolution
of 200 dpi, one enters the following command:
>> print -dtiff -r200 saddle.tiff
Example
To export Figure No. 2 to file spline2d.eps with resolution 600-dpi and
using the EPS color graphics format, one types:
>> print -f2 -r600 -depsc spline2d
Note: The print command provides more flexibility in the type of output
sent to the printer and permits one to control printing from M-files. The result
can be sent directly to the default printer or stored in a specified file. A wide
variety of graphics formats are supported, such as BMP, EPS, JPG, and TIF
files.
C. Exporting figures
The basic options are featured for exporting a figure in a selected graphics
format to a file for another application, such as a word processor.
Using Export Setup GUI
This option permits one to adjust or set the graphic characteristics, such as
text size, font, and style. Figures can be saved using various standard graphics
file formats such as BMP, EPS, JPG, and TIF.
The following select-click sequence opens the Export Setup GUI from the
MATLAB figure window:
>> File >> Export Setup
This GUI has four dialog boxes that enable one to:
1.
2.
3.
4.
Adjust the figure size
Change the rendering
Change font characteristics
Change line characteristics
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After the figure properties have been changed or adjusted, one can follow the
standard Windows GUI procedure to export the figure.
Using MATLAB commands
This option is simply printing a figure to a file using MATLAB commands as
described in the previous section.
Using Windows clipboard
To copy the figure in the current active figure window to Windows clipboard,
one simply applies the following select-click sequence:
>> Edit >> Copy Figure
The figure written to the clipboard has either of the two graphics file formats:
EMF color vector or BMP 8-bit color bitmap. MATLAB selects the
format automatically.
One may choose to adjust the figure settings or change the default graphics
format before writing the figure to the clipboard. This will require the use of
the Copy Options Preferences dialog box, which is opened with the
following select-click sequence:
>> Edit >> Copy Options
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4.7 In-lab Experiments
This experiment consists of a series of MATLAB exercises. All the data created
and resulted from all the experiment exercises should be saved in your USB
flash drive. By doing so you can extract the data needed to write the lab report
following the in-lab session.
Experiment 4.1
(a) Make use of the MATLAB function sinc to create a 2-D line graph of good
resolution defined by
𝑦
sin 𝜋𝑥
𝜋𝑥
𝑠𝑖𝑛𝑐 𝑥
for
10
𝑥
10
(b) Enter the edit-plot mode, then do the following to enhance the graph: (1)
Label the x-axis with ‘x’ and the y-axis with ‘y = sinc(x)’. (2) Change the
default line width from 0.5 point to 2 point. (3) Add grid lines to the graph.
(c) Export the enhanced figure as a JPEG file with filename ‘Group_n_L4_1’,
where n is the number assigned to your lab station.
Experiment 4.2
(a) In a single figure plot three 2-D line graphs of good resolution defined,
respectively, as follows:
𝑓 𝑡
5𝑡 ∙ exp
𝑓 𝑡
5 𝑡
1.5 ∙ exp
𝑓 𝑡
5 𝑡
3.5 ∙ exp
𝑡
5
𝑡
𝑡
1.5
5
3.5
5
where 0 𝑡 10.
(b) Enter the edit-plot mode and adjust or add the following attributes to
enhance the figure: (1) Label the x-axis with ‘t’. (2) Change the default
line style for f2(t) to ‘dash_dot’, and the default line style for f3(t) to
‘dashed’.
(3) Add a legend to the figure using labels ‘f1(t)’, ‘f2(t)’, and
‘f3(t)’.
(c) Export the enhanced figure as an EPS file having the filename
‘Group_n_L4_2’, where n is the number assigned to your lab station.
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Experiment 4.3
(a) Create seven data sequences n, h, H, t1, x, t2, and y using the
following command sequence
>>
>>
>>
>>
>>
n = [0 : 15];
h = [zeros(1, 4), 0.75*ones(1, 8), zeros(1, 4)];
H0 = fft(h); H = fftshift(H0);
t1 = [0 : 10]; x = 0.75*exp(-0.2*t1);
t2 = [0 : 25]; y = conv(h, x);
(b) Create the bar graphs for the data pairs (n, h), (n, H), (t1, x),
and (t2, y) using the stem function and plot them in a single figure
as subplots identified with position indices 1, 2, 3, and 4, respectively.
(c) Export the enhanced figure as an EPS file with filename ‘Group_n_L4_3’,
where n is the number assigned to your lab station.
Experiment 4.4
(a) Create a 3-D line graph with good resolution for a conical helix whose
coordinates are defined by following parametric equations:
𝑥
𝑡 ⋅ 𝑠𝑖𝑛 𝑡 ,
𝑦
𝑡 ⋅ 𝑐𝑜𝑠 𝑡 ,
𝑧
𝑡
for
0
𝑡
10𝜋
(b) Without entering the edit-plot mode, use MATLAB commands to adjust or
add the following attributes to the graph: (1) Label the x-axis, y-axis, and
z-axis with ‘x(t)’, ‘y(t)’, and ‘z(t)’, respectively. (2) Change the default
line width from 0.5 point to 2 point. (3) Add the title ‘Conical Helix’. (4)
Add grid lines.
(c) Export the enhanced figure as a bitmap file with filename ‘Group_n_L4_4’,
where n is the number assigned to your lab station.
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Spring 2024  Professor B.W. Kwan
EEL3002L
Lab #4
ECE Tools Lab
Experiment 4.5
(a) Consider a surface z(x, y) defined as follows:
𝑧 𝑥, 𝑦
𝑠𝑖𝑛𝑐 𝑅
sin 𝜋𝑅
, 𝑅
𝜋𝑅
𝑥
𝑦 ,
3
𝑥. 𝑦
3
Make use of the MATLAB functions sinc and mesh to generate a surface
plot of z(x, y). Label the x-axis, y-axis, and z-axis with ‘x’, ‘y’, and ‘z(x,
y)’, respectively. Export the figure as a JPEG file with filename
‘Group_n_L4_5a’, where n is the number assigned to your lab station.
(Note: The sinc function is defined in Experiment 4.1.)
(b) Repeat part (a), but add the following string to the argument list of the
mesh function:
'EdgeColor', 'black'
Use the filename ‘Group_n_L4_5b’ instead for the exported figure.
(c) Repeat part (a), but use the 3-D plot function surf instead plus two
additional instructions given below:
>> colormap hsv,
>> colorbar
Use the filename ‘Group_n_L4_5c’ instead for the exported figure.
(d) Repeat part (a), but use the 3-D plot function surf instead and include
the following string in its argument list:
'FaceColor', 'red', 'EdgeColor', 'none'
Examine the attribute of the figure. Add the following instructions
sequentially afterward and observe their effects on the figure.
>> camlight left
>> lighting phong
Use the filename ‘Group_n_L4_5d’ instead for the exported figure.
433
Spring 2024  Professor B.W. Kwan
EEL3002L
Lab #4
ECE Tools Lab
Experiment 4.6
The total spending in USA in a recent fiscal year is tabulated below:
Interest on
Debt
Medicare &
Health
Military
SS, Labor &
Unemployment
Others
6.5%
25%
21.5%
35%
12%
(a) Create a pie chart that illustrates the total spending for fiscal year 2013
proposed by the US President.
(b) Repeat part (a) with the largest slice in the pie drawn with an offset.
(c) Export the figures created in parts (a) and (b) as JPEG files with filenames
‘Group_n_L4_6a’ and ‘Group_n_L4_6b’, respectively. Note n is the
number assigned to your lab station.
Experiment 4.7
MATLAB is equipped with two functions for generating random numbers that
follow the uniform distribution and the normal (Gaussian) distribution. These
functions are rand and randn, respectively.
(a) Use the help command to enable you to write a concise description of
the rand function. Then create a 10-bin histogram of 100 random
numbers generated by the rand function.
(b) Use the help command to enable you to write a concise description of
the randn function. Then create a 20-bin histogram of 500 random
numbers generated by the randn function. Use the range [-5, 5] for the
histogram.
(c) Export the figures created in parts (a) and (b) as PNG files with filenames
‘Group_n_L4_7a’ and ‘Group_n_L4_7b’, respectively. Note n is the
number assigned to your lab station.
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Spring 2024  Professor B.W. Kwan
EEL3002L
Lab #4
ECE Tools Lab
Experiment 4.8
The capacitor voltage vC (t ) of a transient RC circuit is given by:
𝑣 𝑡
1.5
5,
3.5𝑒
.
𝑡
, 𝑡
0
0
(a) Sample the capacitor voltage vC (t ) using uniform sampling interval of 0.2
second over the time interval [-2, 5]. Store the sample points in the array
v_c.
(b) Plot v_c as a staircase function of time. Label the axes properly.
(c) Export the figure created in part (b) as an EPS file with filename
‘Group_n_L4_8’. Note n is the number assigned to your lab station.
4.8 Lab Report
Document the experimental results using the format based on the lab report
template.
References
[1] MATLAB documents and resources available at the MathWorks, Inc.
website: www.mathworks.com
[2] Textbook for EEL3111 and EEL3112 OR the textbook for EEL3003.
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Spring 2024  Professor B.W. Kwan