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

iFFmpeg 6.2.2 - Convert multimedia files...
iFFmpeg is a comprehensive media tool to convert movie, audio and media files between formats. The FFmpeg command line instructions can be very hard to master/understand, so iFFmpeg does all the hard... Read more
ForeverSave 2.1.6 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Define your preferred time... Read more
BetterTouchTool 1.961 - 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
EtreCheck 3.1.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Together 3.7 - Store and organize all of...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Features Smart storage. With simple drag-and-drop... Read more
Together 3.7 - Store and organize all of...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Features Smart storage. With simple drag-and-drop... Read more
EtreCheck 3.1.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Postbox 5.0.9 - Powerful and flexible em...
Postbox is a new email application that helps you organize your work life and get stuff done. It has all the elegance and simplicity of Apple Mail, but with more power and flexibility to manage even... Read more
DiskCatalogMaker 6.5.16 - Catalog your d...
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... Read more
TrailRunner 3.8.827 - Route planning for...
TrailRunner is the perfect companion for runners, bikers, hikers, and all people wandering under the sky. Plan routes on a geographical map. Import GPS or workout recordings and journalize your... Read more

Latest Forum Discussions

See All

Enneas Saga lets you lead your own demon...
Defend the land of Enneas Continent from the forces of evil in the new fantasy MMORPG from Lyto Mobi: Enneas Saga. Can’t wait? No problem. It’s available to download now on Android devices. | Read more »
Great zombie games in the spirit of Dead...
Dead Rising 4 arrives tomorrow, giving enthusiasts a fresh chance to take selfies with zombies and get up to other ridiculous end-of-the-world shenanigans. To really get into the spirit of things, we've gone and gathered the best zombie games that... | Read more »
Amateur Surgeon 4 Guide: Advanced tips a...
Amateur Surgeon 4 is still tackling the competition at the top of the App Store charts, so if you haven't tried it out yet, you should probably do that right away. If you've been at it for a while, though, perhaps you're ready to start expanding... | Read more »
Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »

Price Scanner via MacPrices.net

Monday roundup of Holiday Mac sales: Up to $3...
Take up to $300 off MSRP on the price of a new Apple Mac at B&H Photo today as part of their Holiday sale. Shipping is free, and B&H charges NY sales tax only. Touch Bar MacBook Pros are in... Read more
12-inch WiFi Apple iPad Pros on sale for up t...
B&H Photo has 12″ WiFi Apple iPad Pros on sale for up to $50 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $749 $50 off MSRP... Read more
9-inch Apple WiFi iPad Pros on sale for $20-$...
B&H Photo has 9.7″ Apple WiFi iPad Pros on sale for $20-$50 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 9″ Space Gray 256GB WiFi iPad Pro: $779.95 $20 off MSRP... Read more
Holiday sale: Apple MacBook Airs available fo...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $899 $100 off MSRP - 13″ 1.6GHz/... Read more
13-inch Silver Touch Bar MacBook Pro in stock...
Amazon has the new 2016 13″ 2.9GHz/256GB Silver Touch Bar MacBook Pro (MLVP2LL/A) in stock today and on sale for $1749 including free shipping. That’s $50 off MSRP, and it’s the lowest price... Read more
Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more
OWC Mercury Elite Pro Dual mini Ultra-Portabl...
OWC has introduced the new OWC Mercury Elite Pro Dual mini, a powerful yet ultra-portable dual-drive RAID solution. The new Mercury Elite Pro Dual mini packs phenomenal performance into a small... Read more
Clearance 13-inch Retina MacBook Pros availab...
B&H Photo has clearance 2015 13″ Retina Apple MacBook Pros available for up to $200 off original MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $... Read more
Roundup of 2016 13-inch 2.0GHz MacBook Pro sa...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
New 13-inch 2.0GHz Space Gray MacBook Pro in...
Adorama has the new 13″ 2.0GHz Space Gray MacBook Pro (non-Touch Bar, MLL42LL/A) in stock for $1499 including a free 3-year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax... Read more

Jobs Board

Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 53586123 Pittsburgh, Pennsylvania, United States Posted: Nov. 28, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC Read more
*Apple* Retail - Multiple Positions- Plano,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Kansas...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Hardware Design Validation Engineer - *Apple...
The Apple Watch team is looking for a Hardware Design Validation Engineer. This person will be part of the Apple Watch hardware team with responsibilities for Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.