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

Iridient Developer 3.3.12 - Powerful ima...
Iridient Developer (was RAW Developer) is a powerful image-conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
DxO PhotoLab 3.3.0.54 - Image enhancemen...
DxO PhotoLab (was DxO Optics Pro) provides a complete set of smart assisted corrections that you can manually fine-tune at any time. Take control on every aspect of your photos: effectively remove... Read more
Airfoil 5.9.1 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
TunnelBear 3.9.8 - Subscription-based pr...
TunnelBear is a subscription-based virtual private network (VPN) service and companion app, enabling you to browse the internet privately and securely. Features Browse privately - Secure your data... Read more
Things 3.12.4 - Elegant personal task ma...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
Vitamin-R 3.17 - Personal productivity t...
Vitamin-R creates the optimal conditions for your brain to work at its best by structuring your work into short bursts of distraction-free, highly focused activity alternating with opportunities for... Read more
iMazing 2.11.6 - Complete iOS device man...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
BBEdit 13.1 - Powerful text and HTML edi...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Apple Security Update 2020-003 - For mac...
Apple Security Update is recommended for all users and improves the security of OS X. For detailed information about the security content of this update, please visit lists security updates for... Read more
BetterTouchTool 3.379 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more

Latest Forum Discussions

See All

The 5 Best Mobile Real Time Strategy Gam...
Real-time strategy games feel like they’d be a perfect fit for mobile, but they’re trickier to pull off that you might think. The traditional mold of base-building and micro management can work on touch screens, but needs to be carefully honed so... | Read more »
Using your phone in a protest
I can't write about games today. There is a struggle happening in the streets right now and it needs everyone's attention. Here's some good info on how you can use your iOS device safely amidst a protest. | Read more »
Dungonian is a card-based dungeon crawle...
Dungonian is a card-based dungeon crawler from developer SandFish Games that only recently launched as a free-to-play title. It offers an extensive roster of playable heroes to collect and enemies to take down, and it's available right now for iOS... | Read more »
Steam Link Spotlight - Signs of the Sojo...
Steam Link Spotlight is a feature where we look at PC games that play exceptionally well using the Steam Link app. Our last entry was XCOM: Chimera Squad. Read about how it plays using Steam Link's new mouse and keyboard support over here. | Read more »
Steampunk Tower 2, DreamGate's sequ...
Steampunk Tower 2 is a DreamGate's follow up to their previous tower defence game. It's available now for both iOS and Android as a free-to-play title and will see players defending their lone base by kitting it out with a variety of turrets. [... | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Pokemon Go Fest 2020 will be a virtual e...
Niantic has announced that Pokemon Go Fest will still take place this year although understandably it won't be a physical event. Instead, it will become a virtual celebration and is set to be held on 25th and 26th July. [Read more] | Read more »
Marvel Future Fight's major May upd...
Marvel Future Fight's latest update has now landed, and it sounds like a big one. The focus this time around is on Marvel's Guardians of the Galaxy, and it introduces all-new characters, quests, and uniforms for players to collect. [Read more] | Read more »
SINoALICE, Yoko Taro and Pokelabo's...
Yoko Taro and developer Pokelabo's SINoALICE has now opened for pre-registration over on the App Store. It's already amassed 1.5 million Android pre-registrations, and it's currently slated to launch on July 1st. [Read more] | Read more »
Masketeers: Idle Has Fallen's lates...
Masketeers: Idle Has Fallen is the latest endeavour from Appxplore, the folks behind Crab War, Thor: War of Tapnarok and Light A Way. It's an idle RPG that's currently available for Android in Early Access and will head to iOS at a later date. [... | Read more »

Price Scanner via MacPrices.net

Apple’s new 2020 13″ MacBook Pros on sale for...
Apple reseller Abt Electronics has new 2020 13″ MacBook Pros on sale today for up to $140 off MSRP, starting at $1208. Shipping is free, and most configurations are in stock today. Note that Abt’s... Read more
Apple CEO Reacts To Nationwide Protests Over...
NEWS: 06.03.20 – With the recent death of a black man in the custody of a white police officer igniting outrage among Americans from all walks of life, which resulted in protests and civil unrest... Read more
At up to $420 off MSRP, these Certified Refur...
Apple has Certified Refurbished 2019 16″ MacBook Pros available for up to $420 off the cost of new models, starting at $2039. Each model features a new outer case, shipping is free, and an Apple 1-... Read more
Apple restocks refurbished 3rd generation 12....
Apple restocked select 3rd generation 12.9″ WiFi iPad Pros starting at only $699 and up to $330 off original MSRP. Each iPad comes with a standard Apple one-year warranty, outer cases are new, and... Read more
These wireless carriers are offering Apple’s...
Looking for a deal on Apple’s new iPhone SE? Apple itself offers the unlocked 64GB iPhone SE for $399 or $16.62/month. If you’re willing to try a new carrier, two of Apple’s wireless carriers are... Read more
Save $80 on the 64GB 10.5″ iPad Air with this...
Apple has 10.5″ 64GB WiFi iPad Airs models available for $80 off MSRP, Certified Refurbished. Each iPad comes with Apple’s standard one-year warranty and includes a new outer case. Shipping is free... Read more
Apple offers wide range of refurbished custom...
Save up to $7740 on a custom-configured Mac Pro with these Certified Refurbished models available at Apple. Each Mac Pro features a new outer case, free shipping, and includes Apple’s standard 1-year... Read more
Sale! $200 off on select 2020 13″ MacBook Pro...
Amazon has select 2020 13″ MacBook Pro configurations on sale today for $200 off Apple’s MSRP. Shipping is free. Be sure to purchase the MacBook Pro from Amazon, rather than a third-party seller, and... Read more
June 1 only: $100 off Apple’s iPhones at Boos...
Boost Mobile is offering Apple iPhone 11, 11 Pro, and iPhone 11 Pro Max models for $100 off MSRP with service. Their discount reduces the cost of an iPhone 11/64GB to $599, iPhone 11 Pro to $899 for... Read more
Sams Club Sales Event: $100 off every Apple W...
Sams Club is discounting all Apple Watch Series 5 models by $100 off Apple’s MSRP through June 3, 2020. Choose free shipping or free local store pickup (if available). Sale prices for online orders... Read more

Jobs Board

Security Officer ($23.00/Hourly) - *Apple*...
**Security Officer \($23\.00/Hourly\) \- Apple Store** **Description** About NMS Built on a culture of safety and integrity, NMSdelivers award\-winning, integrated Read more
*Apple* Service Desk Analyst - Zones LLC (Un...
Apple Service Desk Analyst Professional Services Albany, New York Apply Description Position OverviewAs a Service Desk Analyst, you will provide customer-friendly Read more
*Apple* Mac Desktop Support - Global Dimensi...
…Operate and support an Active Directory (AD) server-client environment for all Apple devices operating on the BUMED network + Leverage necessary industry enterprise Read more
*Apple* Mac Desktop Support - Global Dimensi...
…Operate and support an Active Directory (AD) server-client environment for all Apple devices operating on the BUMED network + Leverage necessary industry enterprise Read more
Surgical Technologist III, *Apple* Hill Sur...
Surgical Technologist III, Apple Hill Surgical Center - Full Time Tracking Code D5.29.2020 Job Description Surgical Technologist III Apple Hill Surgical Center Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.