TweetFollow Us on Twitter

Dec 98 Online

Volume Number: 14 (1998)
Issue Number: 12
Column Tag: MacTech Online

Advanced C++ Algorithms

by Jeff Clites, online@mactech.com

Algorithms are at the very heart of programming. Fortunately, the C++ standards committee saw fit to include an algorithms library to work in conjunction with the container classes of the STL. Although immensely useful, this library really covers only the most commonly used, general purpose tasks, and for specialized applications you have to look elsewhere. This month we are going to take a tour of some powerful algorithm libraries that pick up where the STL leaves off.

Algorithms in General

There are a number of printed references for learning about algorithms and the theory behind them. Algorithms in C++, 3rd ed., by Robert Sedgewick, is a new version of a classic reference, full of lucid explanations and copious illustrations, and there is a freeware program, MacBalsa, which animates many of the algorithms from the book. The Art of Computer Programming series by Donald E. Knuth is the definitive work on almost all things computing, and it is referenced by just about any writing which mentions the word "algorithm." Numerical Recipes in C by William H. Press, et al, is another classic, with an emphasis on practicality, and the full text is available in pdf form for preview on the web. On the other hand, a page at JPL warns against using the code from Numerical Recipes as-is, so you might want to check out these sites in tandem. For your general algorithm needs, check out Netlib, Codepage, and Programmer's Oasis - they have descriptions and links to a plethora of code sources.

MacBALSA
http://www.eg.bucknell.edu/~zaccone/MacBALSA/MacBALSA.html
Don Knuth's Home Page
http://www-cs-staff.stanford.edu/~knuth/
Numerical Recipes Home Page
http://www.nr.com/
Why not use Numerical Recipes?
http://math.jpl.nasa.gov/nr/
Netlib
http://www.netlib.org/c++/
{Codepage 2.2}
http://www.iro.umontreal.ca/~ratib/code/
Programmer's Oasis: Algorithms, Data Structures
http://www.utu.fi/~sisasa/oasis/oasis-algo.html

Finite-State Machines

Finite-State Machines (or FSMs for short) are based on a mechanical model of computing, originating with the Turing Machine. Although conceptually simple, they are the natural way to express many computational processes, such as string searching or parsing. Object Mentor has code available for an FSM compiler, which allows you to define an FSM with a simple notation and then compile it into code for a set of C++ classes. (Also be sure to check out the cool "Game of Life" applet, Wator, on their home page.) Conveniently, Michael Schürig has done the work of preparing a Mac version of the compiler as a droplet, and it is posted on his web site.

Object Mentor Freeware by Email
http://www.oma.com/Offerings/catalog.html
Michael Schürig's Home Page
http://www.schuerig.de/michael/

Genetic Algorithms

Genetic algorithms are a class of algorithms for solving minimization or best-fit problems, and are especially useful for situations in which classic optimization techniques fail. They are so-named because their basic strategy mimics biology: to find the optimal solution, generate a pool of candidate solutions, take a selection of the best ones and "combine" these to generate a new pool of candidates, and repeat. Unlike other optimization techniques, their successful use often depends heavily on finding the right way to encode the problem, but if used correctly they can succeed despite the presence of local minima which plague other approaches. MIT's GAlib makes it easy to implement a variety of different genetic algorithm strategies, and TimGA is a program which graphically demonstrates the optimization process and lets you experiment with how various parameters effect performance. TimGA is PowerPlant-based, and the code is available online.

GAlib: Matthew's C++ Genetic Algorithms Library
http://lancet.mit.edu/ga/
TimGA Source Code
http://hyperarchive.lcs.mit.edu/cgi-bin/NewSearch?key=TimGA

Parsing

A surprisingly difficult task in compiled languages is to allow the user to input a mathematical expression in text form and then evaluate it. This is a trivial one-liner in interpreted languages such as Perl, Python, and Tcl, but C and C++ don't have access to their own parsers and compilers at runtime, so if you want to do this sort of thing you have to write an interpreter yourself. A helpful starting point is the Chipmunk Basic Home Page, which has a large collection of links to source code. In particular, check out interp2num, an expression evaluator which gives you a choice of allowing C-like or BASIC-like syntax for the expressions it evaluates. Also, the STL-Compliant Software Components Collection page has a tokenizer which can help if you want to start from scratch.

Chipmunk Basic Home Page
http://www.rahul.net/rhn/cbas.page.html
STL-Compliant Software Components Collection
http://corp.metabyte.com/~fbp/stl/components.html

Linear Algebra and Matrix Manipulation

Fortran is famous for high-performance computation, and there a number of well-known libraries for numerical and scientific applications. Although many of these may be available to C and C++ programmers as compiled libraries or by way of the Fortran-to-C compiler, you probably prefer to find true C++ implementations. These allow you to peek under the hood when necessary, and they make it easier to integrate with the rest of your application by providing an object-based interface.

Most of these libraries fall under the general heading of linear algebra, since many problems are naturally expressed in terms of matrices. NIST has developed a library called TNT, the Template Numerical Toolkit, which tackles the difficult problem of developing an efficient yet elegant library for matrix math. One of its design criteria is compatibility with the STL, so that its matrices can act as generic container classes. Oleg Kiselyov's library, called simply LinAlg, is worth a look as well. Even if you do not use it directly, it uses a number of clever programming techniques, such as lazy evaluation and specialized constructors, which are instructive in their own right. Finally, Newmat, by Robert Davies, is a large and well-documented library, and is suitable for working with larger matrices.

Mac F2C
http://www.alumni.caltech.edu/~igormt/Mac_F2C.html
TNT Home Page
http://math.nist.gov/tnt/
Oleg Kiselyov's LinAlg Library
http://hyperarchive.lcs.mit.edu/cgi-bin/NewSearch?key=LinAlg
Newmat09: C++ matrix library
http://webnz.com/robert/nzc_nm09.html

(Pseudo) Random Numbers

It's pretty common for programs to use random number generators, and some are more serious about it than others. (Are you designing a solitaire game or trying to predict tornadoes?) If you need something a little more random than rand() or QuickDraw's Random(), there are alternatives out there. It's ironic, if you think about it, that the better implementations call themselves pseudorandom rather than random, to explicitly acknowledge that you can't really generate truly random numbers on a computer without some extra hardware making quantum measurements. UltraLib is a fast random-number generator, with implementations available in 68K and PPC assembly. It claims to be random even at the bit level, and to have an extremely long period ( 10^356). Agner Fog has another implementation of the same algorithm, as well as an algorithm of his own invention, on his page. Robert Davies, mentioned above, has a random number class library, Newran, which can generate sequences following a number of distributions. Donald E. Knuth's page, also mentioned above, has a public domain random number generator, with code in C or Fortran for single or double precision.

UltraLib
http://hyperarchive.lcs.mit.edu/cgi-bin/NewSearch?key=RandomNumberLib
Agner Fog's Pseudo random number generators
http://announce.com/agner/random/
Newran02A: C++ random number generator library
http://webnz.com/robert/nr02doc.htm
Knuth: Programs
http://www-cs-staff.stanford.edu/~knuth/programs.html

Cryptography

I could certainly write an entire column (or several) on the topic of cryptography, so I will just give a brief pointer here. Bruce Schneier's Applied Cryptography is the definitive reference on the subject, and his Counterpane web site has information on two freely available encryption schemes which he invented, as well as a pseudorandom number generator.

Counterpane Homepage
http://www.counterpane.com/

None of these libraries are Mac-specific; some are fully cross-platform, some have Mac versions available, and some may require tweaking (although less tweaking, now that CodeWarrior has support for member templates). In any case, I hope they are useful starting points.

These and armfuls of other links are available from the MacTech Online web pages at www.mactech.com/online/.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Ember 1.8.3 - Versatile digital scrapboo...
Ember (formerly LittleSnapper) is your digital scrapbook of things that inspire you: websites, photos, apps or other things. Just drag in images that you want to keep, organize them into relevant... Read more
Apple iTunes 12.1 - Manage your music, m...
Apple iTunes lets you organize and play digital music and video on your computer. It can automatically download new music, app, and book purchases across all your devices and computers. And it's a... Read more
LibreOffice 4.4.3 - Free, open-source of...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
FoldersSynchronizer 4.2.1 - Synchronize...
FoldersSynchronizer is a popular and useful utility that synchronizes and backs-up files, folders, disks and boot disks. On each session you can apply special options like Timers, Multiple Folders,... Read more
Simon 4.0.2 - Monitor changes and crashe...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more
Cocktail 8.1.2 - General maintenance and...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more
Cyberduck 4.6.4 - FTP and SFTP browser....
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Herald 5.0.2 - Notification plugin for M...
Note: Versions 2.1.3 (for OS X 10.7), 3.0.6 (for OS X 10.8), and 4.0.8 (for OS X 10.9) are no longer supported by the developer. Herald is a notification plugin for Mail.app, Apple's Mac OS X email... Read more
DEVONthink Pro 2.8.3 - Knowledge base, i...
Save 10% with our exclusive coupon code: MACUPDATE10 DEVONthink Pro is your essential assistant for today's world, where almost everything is digital. From shopping receipts to important research... Read more
Boom 2 1.0.1 - System-wide pro audio app...
Boom 2 is a system-wide volume booster and equalizer app that is designed especially for OS X 10.10 Yosemite. It comes with a smart interface, self-calibrates itself according to your Mac, offers... Read more

Playworld Superheroes Review
Playworld Superheroes Review By Tre Lawrence on January 30th, 2015 Our Rating: :: HERO CRAFTINGUniversal App - Designed for iPhone and iPad It’s all about the imagination, fighting bad creatures — and looking good while doing so.   | Read more »
Join the SpongeBob Bubble Party in this...
Join the SpongeBob Bubble Party in this New Match 3 Bubble Poppin’ Frenzy Posted by Jessica Fisher on January 30th, 2015 [ permalink ] | Read more »
Handpick Review
Handpick Review By Jennifer Allen on January 30th, 2015 Our Rating: :: TANTALIZING SUGGESTIONSiPhone App - Designed for the iPhone, compatible with the iPad Handpick will make you hungry, as well as inspire you to cook something... | Read more »
Storm the Halls of Echo Base in First St...
Storm the Halls of Echo Base in First Star Wars: Galactic Defense Event Posted by Jessica Fisher on January 30th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Contradiction Review
Contradiction Review By Tre Lawrence on January 30th, 2015 Our Rating: :: SPOT THE LIEiPad Only App - Designed for the iPad Contradiction is a live action point and click adventure that’s pretty engaging.   Developer: Tim Follin... | Read more »
Unlock Sunshine Girl in Ironkill with th...
Unlock Sunshine Girl in Ironkill with this special 148Apps code Posted by Rob Rich on January 29th, 2015 [ permalink ] Robo-fighter Ironkill has been out on iOS a | Read more »
Crossroad Zombies Review
Crossroad Zombies Review By Jordan Minor on January 29th, 2015 Our Rating: :: CROSSWALKING DEADiPad Only App - Designed for the iPad Crossroad Zombies is a rough draft of a cool genre mash-up.   | Read more »
Blood Brothers 2 – Tips, Cheats, and Str...
War is hell: Is it the kind of hell you want to check out? Read our Blood Brothers 2 review to find out! Blood Brothers 2, DeNA’s follow-up to the original Blood Brothers, is an intriguing card collecting / role-playing / strategy hybrid. There’s... | Read more »
Blood Brothers 2 Review
Blood Brothers 2 Review By Nadia Oxford on January 29th, 2015 Our Rating: :: AN AGGRAVATING RELATIVEUniversal App - Designed for iPhone and iPad Blood Brothers 2 is built on a simple, solid foundation, but its free-to-play system... | Read more »
I AM BREAD, the Toast of the Town, is Ro...
Have you ever dreamt of being deliciously gluten-y? Do you feel passionate about Rye and Wheat? The guys at Bossa Studios do and that is why they are bringing I AM BREAD to iOS soon. The loafy app will feature all the new content that is being... | Read more »

Price Scanner via MacPrices.net

Intel Aims to Transform Workplace With 5th-Ge...
Intel Corporation today announced the availability of its 5th generation Intel Core vPro processor family that provides cutting-edge features to enable a new and rapidly shifting workplace. To meet... Read more
iOS App Sharalike Introduces New Instant Smar...
Sharalike slideshow and photo management software for iOS, is making it easier than ever to create shareable meaningful moments with its new instant SmartShow technology. Staying organized is a goal... Read more
Apple Becomes World’s Largest Smartphone Vend...
According to the latest research data from Strategy Analytics, as global smartphone shipments grew 31 percent annually to reach a record 380 million units in the fourth quarter of 2014. Apple became... Read more
Cut the Cord: OtterBox Resurgence Power Case...
Dead batteries and broken phones are two of the biggest issues for smartphone users today. Otterbox addresses both with the new Resurgence Power Case for Apple iPhone 6, promising to make those panic... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.6GHz/128GB Retina MacBook Pro: $1199.99 save $100 - 13″ 2.6GHz/... Read more
15-inch 2.5GHz Retina MacBook Pro on sale for...
 B&H Photo has the 15″ 2.5GHz Retina MacBook Pro on sale for $2319.99 including free shipping plus NY sales tax only. Their price is $180 off MSRP, and it’s the lowest price available for this... Read more
Back in stock: Refurbished iPod nanos for $99...
The Apple Store has Apple Certified Refurbished 16GB iPod nanos available for $99 including free shipping and Apple’s standard one-year warranty. That’s $50 off the cost of new nanos. Most colors are... Read more
Apple lowers price on refurbished 256GB MacBo...
The Apple Store has lowered prices on Apple Certified Refurbished 2014 MacBook Airs with 256GB SSDs, now available for up to $200 off the cost of new models. An Apple one-year warranty is included... Read more
New Good Management Suite Simplifies Enterpri...
Good Technology has announced the availability of the Good Management Suite, a comprehensive cross-platform solution for organizations getting started with mobile business initiatives. Built on the... Read more
15-inch 2.0GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished previous-generation 15″ 2.0GHz Retina MacBook Pros available for $1489 including free shipping plus Apple’s standard one-year warranty. Their price is... Read more

Jobs Board

*Apple* Solutions Consultant- Retail Sales (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Event Director, *Apple* Retail Marketing -...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global engagement strategy and team. Delivering an overarching brand Read more
At-Home Chat Specialist- *Apple* Online Stor...
**Job Summary** At Apple , we believe in hard work, a fun environment, and the kind of creativity and innovation that only comes about when talented people from diverse Read more
SW QA Engineer - *Apple* TV - Apple (United...
**Job Summary** The Apple TV team is looking for experienced Quality Assurance Engineers with a passion for delivering first in class home entertainment solutions. **Key Read more
*Apple* Retail - Multiple Positions(US) - Ap...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you re also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.