MAE 8 - Fall 2025
Homework 4
Instructions: Follow the homework solution template. Put all answers in a MATLAB
script named hw4.m. Create a zip archive named hw4.zip to include the following files:
hw4.m,temperature.dat,rainfall.dat,divisibility.m, and piecewise2d.m. Make sure
that both figures 1 and 2 are shown on screen when the homework script is executed. Sub-
mit hw4.zip in Canvas before 10 PM on Saturday 11/1/2025. Use double precision unless
otherwise stated.
Problem 1:
The built-in function clock returns a row vector that contains 6 elements: the first three
are the current date (year, month, day) and the last three represent the current time in
hours (24 hour clock), minutes, and seconds. The seconds is a real number, but all others
are integers. Use function sprintf to accomplish the following formatting exercises.
a) Get the current date and time and store them in p1a. The current date and time
should be the date and time when the grader calls your script.
b) Using the format 'YYYY:MM:DD', write the current date to string p1b. Here, YYYY,
MM, and DD correspond to 4-digit year, 2-digit month, and 2-digit day, respectively.
c) Using the format 'HH:MM:SS.SSSS', write the current time to string p1c. Here, HH,
MM, and SS.SSSS correspond to 2-digit hour, 2-digit minute and 7-character second (2 digits
before the decimal point and 4 digits after the decimal points), respectively.
d) Remove the last 5 characters from the string in part (c) so that the format is now
'HH:MM:SS'. Put the answer into string p1d.
e) Combine the strings in part (b) and part (d) together separated by a single space. Put
the answer in string p1e.
Problem 2:
Use the matrix matA below to perform the following exercises.
matA =
π π/4π/7
π/2π/5π/8
π/3π/6π/9
a) Write the first column of matrix matA into string p2a using a field width of 6
characters with 4 decimal places for each element. The string must show a column vector.
b) Write the middle row of matrix matA into string p2b using a field width of 5 char-
acters with 3 decimal places for each element. The string must show a row vector.
c) Write matrix matA into string p2c using a field width of 16 characters with 14 decimal
places.
d) Write matrix matA into string p2d using %e having a field width of 11 characters
with 5 decimal places.
