Re: Mathcad Use (was Laptop requirement?)

["Ivan E. Rouse" <irouse@LASIERRA.EDU>]

At 14:45 3/8/01 -0500, you wrote:
> Ivan Rouse wrote:
>
> > I realize that Excel and other spreadsheets are everywhere but when a
> > student does a calculation using a spreadsheet it is not at all apparent
> > what method, i.e. equation, he used since the equations are not visible
> > just results.  That seems oppposed to the idea that they should show their
> > work so the instructor knows how they got their results.  Perhaps there are
> > ways that students can explicitly state their equations and get around this
> > problem.  For this reason several departments on our campus have
> > standardized on Mathcad since the equations are up front and clear.
>
> Since you use Mathcad in this way and I have contemplated doing the
> same at times, I wonder how you handle two issues. I assume you have
> students print out their Mathcad workbooks and turn that in. (If it
> was done electronically, this would be less of an issue, but then the
> same goes for Excel.)
>
> 1. A workbook consists of pages which extend both horizontally and
> vertically. By default these pages are not numbered and the page cuts
> don't show up until you do page setup. So it's easy to end up with
> some jumble of printed pages, large numbers of which are blank
> (because it prints every page in a max row x max column matrix),
> unnumbered, and with graphs/equations/etc. extending across page
> cuts. (In all fairness, many of the same problems occur in Excel.)

Some thoughts on possible ways to avoid this:
1. Pages can easily be numbered with headers or footers etc.
2. We urge students to set things up so they don't go beyond the set margin
for the text/math.  This margin is clearly shown on the screen.
Furthermore the page breaks are always visible also.
> 2. Mathcad doesn't quite show everything. In particular, I assume
> there are going to be graphs. But what got graphed? Unless the
> students are very clear about the legends, choice of symbols, etc,
> there's no way of knowing if they graphed say an uncorrected or a
> corrected measurement of magnetic field. It doesn't really help that
> the quantity they called "Mag" on page 3, got redefined on page 5,
> using a constant defined globally on page 7!

Graphs normally show the exact variables that were graphed so at least if
the name is confusing the instructor can look back and see what it was.  Of
course since Mathcad evaluates from top to bottom and left to right it is
not difficult to look at the worksheet and find the most recent definition
of a variable if it has been redefined.  However, students should be taught
to use good descriptive axis and graph labels.  As for globally defined
quantities we generally don't use them because they are confusing and we
discourage students from using them.

> Also Mathcad doesn't
> show what data files were accessed, because this information is
> buried in one of the worst dialog boxes I have ever had the
> misfortune of struggling with in a program, namely the "Associate"
> operation.

We have not had this problem since we normally have students enter their
data  sets (if the data sets aren't too long) directly into one of the
vector definition tables Mathcad uses with subscripted variables.
Certainly data files can be imported or read in but our version of Mathcad
(V 7) doesn't normally make use of the associate command.  So two
suggestions: (1) if students import data you might insist that they list
the data in the worksheet if it isn't a huge data set.  If data sets get
too big, Mathcad automatically puts the data in a scrollable data display
which will then show a subset of 15 of the total set when viewed and
printed (of course you need the live worksheet to see all the data this way)
(2) One neat trick to get data from a spreadsheet is to select and copy the
data in Excel and then paste it into a variable definition in Mathcad such
as A := (past data here.  This puts the data into a data vector which can
easily be accessed with the appropriate subscript on the variable.

> --
> Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
>       U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5026
> mungan@usna.edu    http://physics.usna.edu/physics/faculty/mungan/
Ivan Rouse, Professor and Chair
Physics Department, La Sierra University
4700 Pierce St., Riverside, CA 92515
email: irouse@lasierra.edu
web: http://physics.lasierra.edu/irouse/
phone: 909-785-2137, FAX 909-785-2215