Problems
they encounter might be as simple
as finding the maximum stress in a statically
loaded simple beam, or as complex
as determining the transient response of a
flexing aircraft wing subjected to transient
loads. In any case, there are often lots of
numbers to crunch.
In the past, the sheer volume of calculations
often meant resorting to approximations
and best guesses. When spreadsheet
software came along, the technical community
quickly realized it could be used for
engineering calculations. But spreadsheets
are mostly geared to accounting and finance
and lack support for complex engineering
calculations.
That’s why over 25 years ago we started
using Maple mathematical software. In
earlier releases, it was primarily a calculation engine.
Users invoked suitable commands, provided input,
and the software delivered answers. A later version
introduced the Document mode. It combines the
math capabilities of Maple with the text capabilities
of a word processor. Workflows are similar to those of
paper and pencil. Users employ standard mathematical
expressions, make annotations with text notes to
explain what they are doing and why, and results appear
in the document. Everything is associative and
parametric, so any changes reflect through the entire
document. For a simple example, if x = 3 and y = 7,
then x + y = 10. Change x to 5, and the total immediately
changes to 12.
The later version also included a handwriting-recognition
system so that when you couldn’t remember
which menu contains a specific symbol, you sketched
it with the mouse, and the system would attempt to
find the symbol. Maple 11, the latest release, expands
on this to include formulas and equations instead of
just single characters. The developer emphasizes that
the function is experimental.
Although the idea is clever, a downside is it’s difficult
to draw characters and symbols with a mouse.
Stylus-operated systems for recognizing characters
are approaching 100% hit rates, but I could never get
much above 20% with the mouse-driven system.
That said, Maple 11 boasts an incredible arsenal of
mathematical weaponry. It has more than 4,000 builtin
math functions and 1,000 math symbols. Conversion
factors for over 250 different simple and compound units let users mix and match units. The software
helps users here by “sanity checking.” It displays
an error message when users try to enter a volume
unit when it expects a time unit, or similar incongruities.
Version 11 also includes over new 100 improvements
and additions.
For example, many functions in the program can
be altered by numeric inputs, pushbutton selections,
or sliders, producing 2D or 3D graphical outputs that
change accordingly. If a user varies the parameters of
a complex spring-mass-damper system, the response
graph immediately updates.
An interesting feature of the interface is the new
self-documenting context menus. Consider the following
calculation:
Creating this equation is simple. Just type 2/3, press
the right arrow key, type 5/7, and finally press Ctrl=.
Maple 11 formats the equation as shown and calculates
the result. Now for the self-documenting feature.
Right-click on the answer and then chose, for example
(Approximate 20) from the list of 5, 10, 20, 50, or 100 that appears in the context menu to have the answer
rounded to 20 digits.
Maple 11 converts the fraction to a decimal, rounds
it the selected amount, and adds the arrow and annotation
to indicate what it had done, as shown:
| 2 |
+ |
5 |
= |
29 |
at 20 digits 1.380952380952390952 |
| 3 |
7 |
21 |
To further assist with calculations, the software
sports a new Back-Solver Assistant. It produces the
value for any variable in an equation when you supply
values for the other variables. This trims the time
usually spent in rearranging a formula to solve for a
specific variable.
A nifty capability lets users turn a Maple 11 document
into a slide show. Better yet, slides do not have to
be static. Value inputs, buttons, and sliders are still active.
A presenter might, for example, move a slider to
show how frequency response varies with damping.
Users can also cross reference equations between
documents. For example, suppose a main equation is
stored on a file server. Other documents can point to
it, instead of users recreating the formula in each document.
Better yet, any change to the structure or values of
the master reflects back to the referencing documents.
The computation engine has also been improved.
The developer says the engine is the fastest polynomial
real-root finder in the world and that it will find
the real roots of any polynomial. In addition, Maple
11 now imports from and exports to Excel spreadsheets.
The program has also added a physics package
and a differential-geometry package. Maple 11 comes
from Maplesoft, 615 Kumpf Dr., Waterloo, Ont.,
Canada N2V 1KB, maplesoft.com.
Bill Fane, B.A.Sc, P.Eng, ATC
Bill Fane was a product engineer and then product
engineering manager for Weiser Lock in Vancouver,
B.C., for 27 years and has taught mechanical design
since 1996 at the British Columbia Institute of
Technology.