TweetFollow Us on Twitter

Running NAG F95 on a Mac

Volume Number: 20 (2004)
Issue Number: 6
Column Tag: Programming

Running NAG F95 on a Mac

by Peter Amerl

Was Newton's Apple a Macintosh?

The Measurement Scales Uncovered

With OS X, Apple unleashed a new tool upon the computing community that even Sir Isaac Newton would have been proud to use. Who knows, maybe he would have belonged to those in scientific computing who prefer to use the Unix command line interface, and the X windows interface. Or, maybe he would have liked the slick Mac interface, and its newly found flexibility. Either way, most scientific programmers whom I know (including myself) tend to use the command line interface since their input and output data are weighed in hundreds of mega bytes, and the code often massages and stores the reduced data, thus requiring only a very basic interface. Furthermore, coding for those in science is a means to an end (fame and fortune). Often it is necessary for scientific code to be portable, permitting development on the Mac while enabling compilation on the latest Teraflop Cray, or super cluster. This leads to my criteria for the evaluation of the NAG compiler:

  • A streamlined coding environment

  • a good syntax checker

  • an intuitive and easy to use debugger

  • compiler optimization options

  • options to enforce standards compliance

The bulk of scientific computing is performed using two languages: C, and Fortran. Although C has evolved over the past decades with many new scientific libraries, abstraction layers in C++ simplifying the coding process, it is not always the best choice for scientific computing. Many solved computational problems are available on web sites such as http://www.netlib.org. A good fraction of these routines are coded using one of the Fortran flavors. Consequently, the language is likely to remain a scientific favorite for some time. The selection of third party Fortran compilers available for OS X is quite limited, and unfortunately, a good open source compiler for F90 or F95 is not available to date. Current third party contenders such as NAG F95, IBM XL Fortran, and Absoft ProFortran support compilation of source code for the F77, F90, and F95 standards. This review will discuss the NAG compiler for Mac OS X.

Experiences with the NAG Fortran 95 Compiler

The Nag F95 compiler has a multitude of features, such as automatic file preconnection, IEEE 754 support, automatic garbage collection, memory tracing, undefined variable detection, a random number generator that is seeded based on the time of day, etc.. Yet this is all material that can be obtained from the usual propaganda sheets. Once I had the NAG compiler installed and functioning, the fun started. The compiler options are just what one would expect from a Un*x style Fortran compiler. The following options set it apart from other compilers. It can provide compilation feedback that is color-coded, so that compiler warnings, errors, and informational messages are displayed using different colors. This makes it easier to scan the resulting output for compilation problems. Support for conformance checking is included, although apparently only for the Fortran 95 standard. This conformance checking can be performed in the following ways: the compiler can provide warning messages on the use of extensions to Fortran, syntax that was deleted in the transition to F95, and obsolete syntax and commands. One superb feature that NAG provides with its Fortran compilers is runtime garbage collection that can be enabled with "-gc" during the link phase. In the past, the automatic garbage collection has saved me valuable system resources when a routine repetitively needed to allocate and deallocate a number of large dynamic arrays.

The compiler also accepts, and checks HPF directives, but unfortunately does not compile them into the executable. Through the lack of AltiVec (a.k.a. Velocity Engine) library support, it is clear that NAG created the compiler to serve as a general-purpose, platform independent tool. Mac G4 and G5 users must create wrapper functions in C++ to take advantage of the AltiVec routines, a situation that is less than ideal for those looking for Velocity Engine performance improvements. On the other hand, the lack of these additional functions makes the NAG compiler a good (foolproof) compiler to use for porting code to other platforms. An integrated development environment is not provided with the compiler, further gearing the compiler to command-line or emacs jocks (such as myself). At the time of this writing, the compiler was not designed to work with Xcode. This omission may not be a serious stumbling block as NAG does supply its own graphical debugger, upsf95, derived from the open source ups debugger. Information about it can be found at http://ups.sourceforge.net. I found the debugger to work much like graphical implementations of gdbg. For people with dual processor systems, a more serious omission is the lack of parallel processing support.

I suspect that the NAG compiler is still showing some teething pains. Upon installing the compiler on two systems, a dual G5 running Panther and a G3 running Jaguar, I immediately ran into trouble. On the G5, the compiler could not compile a "Hello World" program. Using the "ieee=full" compilation flag changed the executable favorably, but did not entirely fix the problem. In all fairness, I later found that the error occurred every time I compiled as the OEM user after allowing the system to go to sleep. On the G3 with OS X 10.2.8, the code would not compile under the OEM user. Magically, the problems disappeared when I created a non-administrative user account to compile and execute programs. It is possible the problems were caused by other software packages installed on both computers. After the initial frustration, the compiler ran smoothly. I could even compile and execute about 13000 lines of scientific Fortran 90 code originally destined for the SGI platform without problems.

The Bottom Line

Pros:

The compiler functioned well once its quirks were resolved. To me, the debugger felt much like a graphical version of "gdb" and was very usable. The compiler optimized the code noticeably well considering its lack of AltiVec support. The color-coded compilation messages are an excellent touch, and of great benefit to command line compilation. Most important to me, the garbage collection, and cross-platform compatibility functioned superbly.

Cons:

The lack of an IDE or Xcode compatibility forces the user to rely on other editors. Also missing is the ability to compile code for parallel processing. It appears that on some systems, the compiler can potentially act somewhat capriciously. Fortunately, using a non-administrative account with no additional software or haxies installed fixed code generation problems for me.

Recommendations

For anyone who has a favorite editor, and prefers to use make files, this compiler will be worthwhile. If Xcode integration is desired, the NAG F95 compiler is not the tool to use. Perhaps, with properly placed suggestions from users, NAG will support Xcode development in a future release. If you are looking for cross platform compatibility you will most likely also be well served. Before using the compiler I suggest the creating a clean user account. Once this is accomplished, run the compiler from within that account. In any case, this is an excellent practice for computer security.

In Closing

Regardless of the compiler and operating system, the Apple Macintosh would not have been suitable for Sir Isaac Newton. It would likely have rendered him unconscious, or worse, as it fell on his head. Who knows, we might not know about gravity, or calculus, without Newton's contributions. Although most students would be much happier without these, it would also make present day computers unlikely.


Peter Amerl is a PhD physicist who has been coding scientific data reduction routines, and charged particle trajectory simulations for scientific instruments using Fortran 90 and 95 since 1996. Peter started his computing experience in 1982 with the Apple II+, eventually graduating to the Mac+. For a time of about seven years, he turned to the dark side until 1994, when the stability of Linux caught his eye. This fairytale continued until a wondrous discovery - OS X. Now Peter happily codes scientific routines on a G5.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Tidy Up 5.3.7 - Find duplicate files and...
Tidy Up is a full-featured duplicate finder and disk-tidiness utility. Features: Supports Lightroom: it is now possible to search and collect duplicates directly in the Lightroom library. Multiple... Read more
Pinegrow 5.97 - Mockup and design web pa...
Pinegrow (was Pinegrow Web Designer) is desktop app that lets you mockup and design webpages faster with multi-page editing, CSS and LESS styling, and smart components for Bootstrap, Foundation,... Read more
BlueStacks 4.210.0 - Run Android applica...
BlueStacks App Player lets you run your Android apps fast and fullscreen on your Mac. Feature comparison chart How to install Bluestacks on your Mac Go to MacUpdate and click the green "Download"... Read more
WhatsApp 2.2027.10 - Desktop client for...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
Art Text 4.0.1 - $29.99
Art Text is graphic design software specifically tuned for lettering, typography, text mockups and various artistic text effects. Supplied with a great variety of ready to use styles and materials,... Read more
Adobe Dreamweaver CC 2020 20.2 - Build w...
Dreamweaver CC 2020 is available as part of Adobe Creative Cloud for as little as $20.99/month (or $9.99/month if you're a previous Dreamweaver customer). Adobe Dreamweaver CC 2020 allows you to... Read more
Adobe Acrobat DC 20.009.20074 - Powerful...
Acrobat DC is available only as a part of Adobe Creative Cloud, and can only be installed and/or updated through Adobe's Creative Cloud app. Adobe Acrobat DC with Adobe Document Cloud services is... Read more
beaTunes 5.2.10 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
DiskCatalogMaker 8.1.5 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Meteorologist 3.4.1 - Popular weather ap...
Meteorologist is a simple interface to weather provided by weather.com. It provides the ability to show the weather in the main menu bar, displaying more detail in a pop-up menu, whose contents are... Read more

Latest Forum Discussions

See All

Steam Link Spotlight - Disco Elysium
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 Signs of the Sojourner Read about how it plays using Steam Link over here. | Read more »
Distract Yourself With These Great Mobil...
There’s a lot going on right now, and I don’t really feel like trying to write some kind of pithy intro for it. All I’ll say is lots of people have been coming together and helping each other in small ways, and I’m choosing to focus on that as I... | Read more »
Pokemon Go's July Community Day wil...
Pokemon Go developers have announced the details concerning the upcoming Gastly Community Day. This particular event was selected by the players of the game after the Gas Pokemon came in second place after a poll that decided which Pokemon would... | 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 »
Detective Di is a point-and-click murder...
Detective Di is a point-and-click murder mystery set in Tang Dynasty-era China. You'll take on the role of China's best-known investigator, Di Renjie, as he solves a series of grisly murders that will ultimately lead him on a collision course with... | Read more »
Dissidia Final Fantasy Opera Omnia is se...
Dissidia Final Fantasy Opera Omnia, one of Square Enix's many popular mobile RPGs, has announced a plethora of in-game events that are set to take place over the summer. This will include several rewards, Free Multi Draws and more. [Read more] | Read more »
Sphaze is a neat-looking puzzler where y...
Sphaze is a neat-looking puzzler where you'll work to guide robots through increasingly elaborate mazes. It's set in a visually distinct world that's equal parts fantasy and sci-fi, and it's finally launched today for iOS and Android devices. [... | Read more »
Apple Arcade is in trouble
Yesterday, Bloomberg reported that Apple is disappointed in the performance of Apple Arcade and will be shifting their approach to the service by focusing on games that can retain subscribers and canceling other upcoming releases that don't fit... | Read more »
Pixel Petz, an inventive platform for de...
Pixel Petz has built up a sizeable player base thanks to its layered, easy-to-understand creative tools and friendly social experience. It revolves around designing, trading, and playing with a unique collection of pixel art pets, and it's out now... | Read more »
The King of Fighters Allstar's late...
The King of Fighters ALLSTAR, Netmarble's popular action RPG, has once again been updated with a plethora of new content. This includes battle cards, events and 21 new fighters, which increases the already sizeable roster even more. [Read more] | Read more »

Price Scanner via MacPrices.net

Clearance 2019 13″ 2.4GHz/256GB MacBook Pro o...
B&H Photo has dropped their price on the clearance 2019 13″ 2.4GHz/256GB Quad-Core Silver MacBook Pro by $500 off Apple’s original MSRP to a new low of only $1299. Expedited shipping is free to... Read more
$219 Apple AirPods Pro are back at Verizon, s...
Verizon has Apple AirPods Pro on sale again for a limited time for $219.99 on their online store. Their price is $30 off Apple’s MSRP, and it’s the lowest price we’ve seen for AirPods Pro. Available... Read more
Apple’s $779 13″ MacBook Air deal returns to...
Apple has clearance, Certified Refurbished, 2019 13″ MacBook Airs available again starting at $779. Each MacBook features a new outer case, comes with a standard Apple one-year warranty, and is... Read more
$200 13″ MacBook Pro discounts are back at Am...
Amazon has 2020 13″ 2.0GHz MacBook Pros on sale again today for $150-$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
Deal Alert! Apple AirPods with Wireless Charg...
Sams Club has Apple AirPods with Wireless Charging Case on sale on their online store for only $149.98 from July 6, 2020 to July 9, 2020. Their price is $50 off Apple’s MSRP, and it’s the lowest... Read more
Xfinity Mobile promo: Apple iPhone XS models...
Take $300 off the purchase of any Apple iPhone XS model at Xfinity Mobile while supplies last. Service plan required: – 64GB iPhone XS: $599.99 save $300 – 256GB iPhone XS: $749.99 save $300 – 512GB... Read more
New July 2020 promo at US Cellular: Switch an...
US Cellular has introduced a new July 2020 deal offering free 64GB Apple iPhone 11 smartphones to customers opening a new line of service. No trade-in required, and discounts are applied via monthly... Read more
Apple offers up to $400 Education discount on...
Apple has launched their Back to School promotion for 2020. They will include one free pair Apple AirPods (with charging case) with the purchase of a MacBook Air, MacBook Pro, iMac, or iMac Pro (Mac... Read more
July 4th Sale: Woot offers wide range of Macs...
Amazon-owned Woot is blowing out a wide range of Apple Macs and iPads for July 4th staring at $279 and ranging up to just over $1000. Models vary from older iPads and 11″ MacBook Airs to some newer... Read more
Apple Pro Display XDR with Nano-Texture Glass...
Abt Electronics has Apple’s new 32″ Pro Display XDR model with the nano-texture glass in stock and on sale today for up to $144 off MSRP. Shipping is free: – Pro Display XDR (nano-texture glass): $... Read more

Jobs Board

Physical Therapist Assistant - *Apple* Hill...
Physical Therapist Assistant - Apple Hill Rehab - Full Time Tracking Code 62519 Job Description General Summary: Under the direct supervision of a licensed Physical Read more
Operating Room Assistant, *Apple* Hill Surg...
Operating Room Assistant, Apple Hill Surgical Center - Full Time, Day Shift, Monday - Saturday availability required Tracking Code 62363 Job Description Operating Read more
Perioperative RN - ( *Apple* Hill Surgical C...
Perioperative RN - ( Apple Hill Surgical Center) Tracking Code 60593 Job Description Monday - Friday - Full Time Days Possible Saturdays General Summary: Under the Read more
Product Manager, *Apple* Commercial Sales -...
Product Manager, Apple Commercial Sales Austin, TX, US Requisition Number:77652 As an Apple Product Manager for the Commercial Sales team at Insight, you Read more
*Apple* Mac Product Engineer - Barclays (Uni...
Apple Mac EngineerWhippany, NJ Support the development and delivery of solutions, products, and capabilities into the Barclays environment working across technical Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.