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.

 
AAPL
$116.31
Apple Inc.
+1.64
MSFT
$48.70
Microsoft Corpora
+0.48
GOOG
$534.83
Google Inc.
-2.16

MacTech Search:
Community Search:

Software Updates via MacUpdate

Herald 5.0.1 - 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
Firetask 3.7 - Innovative task managemen...
Firetask uniquely combines the advantages of classical priority-and-due-date-based task management with GTD. Stay focused and on top of your commitments - Firetask's "Today" view shows all relevant... Read more
TechTool Pro 7.0.6 - Hard drive and syst...
TechTool Pro is now 7, and this is the most advanced version of the acclaimed Macintosh troubleshooting utility created in its 20-year history. Micromat has redeveloped TechTool Pro 7 to be fully 64... Read more
PhotoDesk 3.0.1 - Instagram client for p...
PhotoDesk lets you view, like, comment, and download Instagram pictures/videos! (NO Uploads! / Image Posting! Instagram forbids that! AND you *need* an *existing* Instagram account). But you can do... Read more
SuperDuper! 2.7.3 - Advanced disk clonin...
SuperDuper! is an advanced, yet easy to use disk copying program. It can, of course, make a straight copy, or "clone" -- useful when you want to move all your data from one machine to another, or do... Read more
MacJournal 6.1.5 - Create, maintain, and...
MacJournal is the world's most popular journaling software for the Mac. MacJournal 6 adds a calendar mode that show entries from any journal, geolocation, word count, and progress tracking, as well... Read more
Skim 1.4.10 - PDF Reader and note-taker...
Skim is a PDF reader and note-taker for OS X. It is designed to help you read and annotate scientific papers in PDF, but is also great for viewing any PDF file. Skim includes many features and has a... Read more
FontExplorer X Pro 4.2.2 - Font manageme...
FontExplorer X Pro is optimized for professional use; it's the solution that gives you the power you need to manage all your fonts. Now you can more easily manage, activate and organize your... Read more
SoftRAID 5.0.5 - High-quality RAID manag...
SoftRAID allows you to create and manage disk arrays to increase performance and reliability. SoftRAID's intuitive interface and powerful feature set makes this utility a must have for any Mac OS X... Read more
DEVONthink Pro 2.8.2 - 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

Latest Forum Discussions

See All

Sago Mini Road Trip (Education)
Sago Mini Road Trip 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: Go for a fun-filled drive with Jinja the cat. Pick a destination, select a vehicle and hit the road. What will Jinja... | Read more »
New Tower Defense Game, Kingdom Rush: Or...
New Tower Defense Game, Kingdom Rush: Origins, is Available Today Posted by Jessica Fisher on November 20th, 2014 [ permalink ] iPad Only App - Designed for the iPad | Read more »
Sunburn! (Games)
Sunburn! 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: Your ship is gone. Your crew is scattered. One option remains. Gather your crew... and jump into the sun. Reunite your... | Read more »
Tapventures Review
Tapventures Review By Jennifer Allen on November 20th, 2014 Our Rating: :: ODDLY COMPELLINGUniversal App - Designed for iPhone and iPad Tapventures is an increasingly hands-off one-tap RPG, but expect it to hook you despite your... | Read more »
Who Wore it Best? The Hunger Games: Girl...
With The Hunger Games: Mockingjay Part 1 out this weekend, Who Wore it Best? pits two Hunger Games tie-ins, Girl on Fire and Panem Run, against each other in a brutal and pointless fight to the death. I wonder where we got that idea from? | Read more »
Ironkill Review
Ironkill Review By Jennifer Allen on November 20th, 2014 Our Rating: :: LACKLUSTER PUNCHINGUniversal App - Designed for iPhone and iPad Ironkill is a freemium focused fighting game that doesn’t offer particularly thrilling fights... | Read more »
Real-Time Multiplayer Match-3 RPG Crusad...
Real-Time Multiplayer Match-3 RPG Crusaders Quest Set to Launch Next Month Posted by Ellis Spice on November 20th, 2014 [ permalink ] | Read more »
Checkpoint Champion Review
Checkpoint Champion Review By Jennifer Allen on November 20th, 2014 Our Rating: :: SPEEDY DRIFTINGUniversal App - Designed for iPhone and iPad Checkpoint Champion is a drift-focused racing game that’s ideal for short but fun gaming... | Read more »
MediaFire iOS 8 Native Update Brings New...
MediaFire iOS 8 Native Update Brings New “Power Upload” Feature to iPad and iPhone Posted by Jessica Fisher on November 20th, 2014 [ | Read more »
Mark of the Dragon Review
Mark of the Dragon Review By Nadia Oxford on November 20th, 2014 Our Rating: :: TRAIN YOUR DRAGON FOR WARUniversal App - Designed for iPhone and iPad Mark of the Dragon is a bit rough and scaly, but flying into battle on the backs... | Read more »

Price Scanner via MacPrices.net

64GB iPod touch on sale for $249, save $50
Best Buy has the 64GB iPod touch on sale for $249 on their online store for a limited time. Their price is $50 off MSRP. Choose free shipping or free local store pickup (if available). Sale price for... Read more
15″ 2.2GHz Retina MacBook Pro on sale for $17...
 B&H Photo has the 2014 15″ 2.2GHz Retina MacBook Pro on sale for $1799.99 for a limited time. Shipping is free, and B&H charges NY sales tax only. B&H will also include free copies of... Read more
New Logitech AnyAngle Case/Stand Brings Flexi...
Logitec has announced the newest addition to its suite of tablet products — the Logitech AnyAngle. A protective case with an any-angle stand for iPad Air 2 and all iPad mini models, AnyAngle is the... Read more
2013 15-inch 2.0GHz Retina MacBook Pro availa...
B&H Photo has leftover previous-generation 15″ 2.0GHz Retina MacBook Pros available for $1499 including free shipping plus NY sales tax only. Their price is $500 off original MSRP. B&H will... Read more
16GB Retina iPad mini on sale today for $199,...
 Staples has 2nd generation 16GB Retina iPad minis on sale for $199 on their online store for a limited time. Their price is $100 off MSRP. Choose free shipping or free local store pickup (if... Read more
Developers Start Designing Apps for Apple Wat...
Apple has announced the availability of WatchKit, software that gives developers a set of tools to easily create experiences designed specifically for Apple Watch. Apple’s developer community can now... Read more
C Spire Launches iPad Air 2 and iPad Mini 3 o...
C Spire has announced that iPad Air 2 with Wi-Fi + Cellular and iPad mini 3 with Wi-Fi + Cellular are now available on its 4G LTE network. C Spire offers both new iPads with a range of data plans... Read more
Are You On Your Last PC? – The ‘Book Mystique
Will your current PC be your last? Quite possibly so if you define “personal computer” as a traditional desktop or laptop form factor machine according to some commentators. So then, the upshot that... Read more
Save up to $180 on MacBook Airs with Apple re...
The Apple Store has Apple Certified Refurbished 2014 MacBook Airs available for up to $180 off the cost of new models. An Apple one-year warranty is included with each MacBook, and shipping is free.... Read more
16GB iPad mini available for $219, save $30
Walmart has 16GB iPad minis (1st generation) available for $219 on their online store. Their price is $30 off MSRP. Choose free shipping or free store pickup (if available). Price for online orders... Read more

Jobs Board

*Apple* Store Leader Program - College Gradu...
Job Description: Job Summary As an Apple Store Leader Program agent, you can continue your education as you major in the art of leadership at the Apple Store. You'll Read more
*Apple* Retail - Multiple Positions (US) - A...
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
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
*Apple* Retail - Multiple Positions (US) - A...
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
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.