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Re: Looking for Long Tooth...



Add graphics to the list. Stretching, rotating, twisting, mapping, 
inverting, compressing bit-mapped images is just plain old bit-twiddling.

Jason

At 09:31 AM 4/9/2003 -0400, Scott P. Smith wrote:
>I am a little surprised by this question and the other one like it a few
>weeks ago.  I have a sneaky feeling that I am helping a college student do
>his homework, but I'll respond anyway.
>
>There are infinitely many ways these operators can be useful.. But I'll just
>give a few examples:
>
>* Data Compression - Many data compression algorithms compress byte streams
>into bit streams.  To create (and later decode) the bit streams, you need
>bitwise operators.
>
>* Non-Java Binary File I/O - When working with binary files that were
>created in C, C++, etc. you will see a lot of use of things like unsigned
>16, and 32 bit values. Since Java doesn't support these, you have to use
>bitwise operators to put the uint16 into a Java int32. And vise versa.
>
>* Old file formats - Like the previous example.  A long time ago, (when
>dinosaurs still roamed the earth and when I was in high-school)  people did
>not have much disk space.  So file formats made HEAVY use of bit fields to
>store a series of boolean flags.  To read or write these flags use need -
>bitwise operators.
>
>* Arbitrarily Precision Integer Math - Math packages that implement 64, 128,
>256 bit integers, etc.  These packages use bitwise operators (at least I
>think they do).
>
>* Hardware Simulation - Hardware adders multipliers etc. are sometimes
>simulated in software using bitwise operations. Not common, but I did this
>back in School.
>
>Scott Smith
>
>
>----- Original Message -----
>From: "Lee Chalupa" <lchalupa@seelink.org>
>To: "Atlanta Java Users Group" <ajug-members@ajug.org>
>Sent: Wednesday, April 09, 2003 9:24 AM
>Subject: Looking for Long Tooth...
>
>
> > Hello:
> >
> > I would like to find some examples of business problems that are addressed
> > using
> > bitwise operators or shift operators.
> >
> > I think one of the reasons people have trouble with these two topics is
> > that they
> > seem irrelevant to their work.
> >
> > My guess is that some of our more experienced programmers used these
> > operators in the "good old days".
> >
> > Does anybody have some practical examples of where they put these
>operators
> > to good use?
> >
> > Thanks
> >
> > Lee Chalupa
> > AJUG Certification Group
> >
> >