Course Catalog Listing Spring 2000 (section 0101)
Please send me an e-mail immediately if something is not clear about the homework, or you suspect there is a typo!
Assignment 5: Typo in Problem 3(a): It should say -v''(t) = 40 sin v(t) (the ``sin'' was missing).
Instructions for using Matlab for ODEs. Also explains how to convert a second order ODE to a first order system of ODEs (needed for all homework problems).
Midterm exam: The average is 75.4. The highest 25% of the class were between 98 and 93, the next 25% were between 93 and 76, the next 25% were between 76 and 62, the lowest 25% were between 62 and 46.
If you have questions about the grading of the homeworks: Please contact the grader
Feiyue Li, office MTH 4423, e-mail lify@math.umd.edu, office hours Mon Wed 1:00-2:00pm
syms x % declare x as symbolic variable y = sin(sin(x)) diff(y,x) % find derivative taylor(y,x,10) % find Taylor series up to order 10
Download the files num2bin.m and bin2num.m (note that you have to put the files where Matlab can find them)
For a Matlab number x the command s=num2bin(x) gives
a string of length 64 of zeros and ones with the machine representation of
x. For a string s of length 64 of ones and zeros the
command x=bin2num(s) gives the corresponding number
x.
As explained in class, s(1) contains the sign,
s(2:12) contains the exponent information, s(13:64)
contains digits d2,...,d53 of the
mantissa (for normalized numbers).
The exponent e is related to this by
e=bin2dec(s(2:12))-1022 or
s(2:12)=dec2bin(e+1022,11)
Try this out with x = 1, 0.1, realmin,
realmax, 0, -0, Inf,
-Inf, NaN
If you are not familiar with Matlab:
Some of the links on this page are marked as ``(Postscript)''. If your browser is set up correctly, clicking on the link will bring up a Postscript viewer which allows you to view and print the document.
If you clicking on the link does not work for you, do the following: click on
the link with the right mouse button so that a menu comes up. Select
"Save link as..." in this menu. Then a dialog box appears which allows you to
save the file in your home directory. Click "OK". On WAM and Glue Unix
computers you can send this file to the printer by typing qpr
filename.ps . You can view the document on the screen by typing
ghostview filename.ps .
On a PC you can install Ghostview to view and print the file.
For each problem hand in
problemX.m (and of all m-files called from
problemX.m) containing the Matlab commands, and comments
answering the questions asked in the problem. Also include comments for each
plot command indicating which of the attached graphics it produced.
problemX.m. Make sure that all output
is labeled so that it is clear what each number means and by what line in the
.m file it was generated.
Use ``;'' at the end of lines to suppress the output of
uninteresting intermediate results (especially if these are large arrays).
problemX.m so that it is clear which Matlab command
produced which graphic.
(On Glue and WAM the Matlab command print figXY.ps produces a
postscript file figXY.ps of the current figure which you can then
send to the printer.)
problemX.m.
tap matlab and then type
matlab
Alternatively: Buy Matlab student version for about $90 at the campus book store and use your own computer (Windows 95, 98, NT; Linux).
Matlab Primer (Postscript file, 35 p.): Explains basic Matlab commands
This is a Postscript file. On WAM and Glue Unix computers you can save the
file. Then you can view it by typing ghostview filename.ps or you
can print it using qpr filename.ps . On a PC you can install Ghostview to view and print
the file.