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RE: MathCAD

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There is always an error, it just has not been found yet.  Also the design
assumptions might not match the situation.  etc...etc...etc...

I have had designers get mad at me for writing a comment on a spreadsheet
that had been used for a long time.  I have also found errors in my stuff
after using it for a long time.  At work I have people use my stuff and
sometimes they find errors and sometimes I find one a year later after other
people have been using it.

There is no substitute for understanding the concept, gut feelings and being
able to recognize a discrepancy in output.  Blind trust in a black box's
output will eventually bring down a dam, high rise, bridge, airliner or
space ship.

-----Original Message-----
From: Christopher Wright [mailto:chrisw(--nospam--at)skypoint.com]
Sent: Saturday, August 10, 2002 11:02 AM
To: ?
Subject: Re: MathCAD


>The seal of approval will be taken to imply that the
>results are good if it achieves an answer - and it WILL be used blindly
>in the name of time efficiency.
Unless some serious work has been put into error trapping and 
diagnostics, I think it's nuts, not to say irresponsible, to go handing 
stuff around willy-nilly, large office or small. Any sort of 'seal of 
approval' is foolhardy, unless the original author is willing to maintain 
control of the spreadsheet and offer support. Quite honestly, if I found 
a subordinate simply copying someone else's work blindly, we'd have a 
brief, emphatic chat on quality and the impact of error correction on 
time efficiency. 

That said, my experience is that a library of worksheets can be very 
helpful once the variables are properly identified, and the worksheets 
audited. Collecting associated worksheets into workbooks with consistent 
notation is also a good idea. Handing stuff around without some control 
is a bad idea, regardless of whether it's MathCAD, Excel, ANSYS macros or 
roll-your-own computer code. Sharing really sounds good on the face of 
it, but as a practical matter it costs a fair amount of time, either 
making it bullet-proof or in the additional checking of assumptions and 
results.

>There is a Mac shareware product called MathPad,
A pretty nice piece of work, but no comparison to something like a real 
package with exportable worksheets.

>last version of MathCad (Plus 6) for Mac in the US$25 range.
The Mac MathCAD port totally sucks. The $25 would be better spent on 
pencils to use on the backs of envelopes. I tried the first version, but 
it was too wobbly to be much more than a plaything, so it didn't sell. 
They tried again and didn't do any better. Their patronizing technical 
support really turned me off. 

Maple is a pretty good product, but pricy and aimed at scientific users 
rather than engineering calculations. If only because of its pedigree 
(It's a descendent of Mathematica which is the best there is, and which 
first came out for the Mac. Stephen Wolfram knows good hardware when he 
sees it.) Calculation Center looks pretty good

>There are also some old copies of Lotus 1-2-3 for Mac
Lotus!!!?? 

Christopher Wright P.E.    |"They couldn't hit an elephant at
chrisw(--nospam--at)skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/~chrisw


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