If they're younger they should have more flexibility of mind than you. Feel free to point this out :-).
If they're bigger they shouldn't need the torches and pitchforks.
So what are they, FPGA designers or readers of cookbooks?
Were it me I'd assess the differences in development time and performance for the two approaches, then jigger the numbers to what I wante -- I mean I'd let the best approach win.
-- www.wescottdesign.com
Here in the U.S. I'd suggest checking with Cal Crystal Lab / Comclok. They claim that "Custom frequencies - our specialty", they have no minimum order quantities, and on the one occasion I dealt with them I found them to be quite friendly to the small-shop developer. I've heard similar good things about them from some other folks who have used their services.
--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Oh, in this case, I agree. It's not hard to simply work out a problem like this by hand -- done it many times, myself. An efficient program using recurrences is more a demonstration of mathematical education than outright utility.
In this program's case, it illustrates to me that the author was somehow exposed to this recurrence method -- probably some reading at some point -- and wanted to embody it in an algorithm. Sadly, the author was not _also_ exposed to better numerical methods for actually computing the terms using a design by someone crafting around the limitations of floating point computations on computers. The line used to compute the next term, line 15, is very very poorly designed. It's straight out of "the book," so to speak. It's the very first way one learns to do it. But it is obvious the author was NOT exposed to good methods for computing terms. People like Bill Gosper know how to do this well, by the way, to drop a singularly important name in this area. The program author obviously hadn't much education on that side of the mathematical road.
So it is a case of selective education and showing off one side, without knowing much on another.
My point about a thorough grounding in recurrences and generating functions remains, though. And given this program's lack of skill in getting the most out of floating point, I'd recommend a good text on numerical methods, as well. One that deals with theory, not practice so much. One needs to learn to fish for themselves, not eat fish others catch for them.
Jon
Jan Crystals, Ft. Myers FL. Google for the web page.
Jim WX6RST
Toothpaste on window glass. Grind it a little too far you could bring it back up with a few lines of pencil lead (graphite).
Jim
FT-243
Jim
Another thing we like to do is to run DDSs backwards, at negative frequencies. You can do stuff like simulate quadrature encoders, or make polyphase motors run in either direction. That's easy in binary.
John
What's wrong with the likes of the Fox XpressO service?
Dave.
-- --------------------------------------------- Check out my Electronics Engineering Video Blog & Podcast: http://www.alternatezone.com/eevblog/
Nice! Thanks. And right here in Kahlifohniah, cool. For John and others who may be interested:
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
On Mon, 15 Jun 2009 22:19:02 -0400, Spehro Pefhany wrote: ...
"High school 'birdbath'"?
??? Rich
Yeah, that's an odd expression. Maybe he's from England?
Bob
-- == All google group posts are automatically deleted due to spam ==
What did you guys call these things? Or do you recognize them)
Best regards, Spehro Pefhany
-- "it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Hmmm. Maybe it's a birdbath. Or, it could be a cotton candy machine.
I don't recall seeing any birdbaths in high school. A lot of birds (aka girls), but they wouldn't let us watch them take their baths in high school.
Bob
-- == All google group posts are automatically deleted due to spam ==
This
ftp://jjlarkin.lmi.net/Lap-Tech.JPG
is a 40 MHz oven-type vacuum-sealed glass AT-cut crystal that is made for us by Lap-Tech in Ontario. They mark the turning-point temperature on each one. These are superb crystals... high Q, low aging. They look like little pieces of jewelry.
John
Neet.
Glass? It would be much more poetic to use pure fused quartz. And a sintered quartz plug for the white part.
And, uh... non-stoichiometric SiO2 for the leads I guess???...
Oh well.
Tim
-- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
We had those in the metalshop and woodshops in Jr. High & high school. The called them 'institutional sinks'.
-- You can\'t have a sense of humor, if you have no sense!
I've got some 1-1/2" long glass ones in the 100kHz range here that look very posh. And yeah, they were also sinfully expensive.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
These are about $12.
John
Hand sink?
Cheers! Rich
I added a short DOS program (yes, it runs under WinXP and doesn't tie up the processor, when running -- it uses the multiplex interrupt to pass back unneeded CPU time to Windows) to display the convergents of continued fraction values. It includes a calculator feature and displays floating point notation, as well. Kind of a swiss army knife thing.
The ZIP simply contains the DOS exe file.
It shouldn't be too hard to use. But you'll need the DOS box. It will run on DOS-only systems and old Windows stuff, as well. Just a QB program. It's free to have, pass around, etc. If anyone wants the code, that's free, too. Just ask. It's a zero-order attempt, but seems to work modestly well.
Jon
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