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

PDFKey Pro 4.3 - Edit and print password...
PDFKey Pro can unlock PDF documents protected for printing and copying when you've forgotten your password. It can now also protect your PDF files with a password to prevent unauthorized access and/... Read more
Kodi 15.0.beta1 - Powerful media center...
Kodi (was XBMC) is an award-winning free and open-source (GPL) software media player and entertainment hub that can be installed on Linux, OS X, Windows, iOS, and Android, featuring a 10-foot user... Read more
DiskCatalogMaker 6.4.12 - 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
Macs Fan Control 1.3.0.0 - Monitor and c...
Macs Fan Control allows you to monitor and control almost any aspect of your computer's fans, with support for controlling fan speed, temperature sensors pane, menu-bar icon, and autostart with... Read more
Lyn 1.5.11 - Lightweight image browser a...
Lyn is a lightweight and fast image browser and viewer designed for photographers, graphic artists and Web designers. Featuring an extremely versatile and aesthetically pleasing interface, it... Read more
NeoOffice 2014.11 - Mac-tailored, OpenOf...
NeoOffice is a complete office suite for OS X. With NeoOffice, users can view, edit, and save OpenOffice documents, PDF files, and most Microsoft Word, Excel, and PowerPoint documents. NeoOffice 3.x... Read more
LaunchBar 6.4 - Powerful file/URL/email...
LaunchBar is an award-winning productivity utility that offers an amazingly intuitive and efficient way to search and access any kind of information stored on your computer or on the Web. It provides... Read more
Remotix 3.1.4 - Access all your computer...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more
DesktopLyrics 2.6.6 - Displays current i...
DesktopLyrics is an application that displays the lyrics of the song currently playing in "iTunes" right on your desktop. The lyrics for the song have to be set in iTunes; DesktopLyrics does nothing... Read more
VOX 2.5.1 - Music player that supports m...
VOX is a beautiful music player that supports many filetypes. The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all... Read more

This Week at 148Apps: May 18-22, 2015
May Days at 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above the... | Read more »
Biz Builder Delux (Games)
Biz Builder Delux 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Ah, there's nothing like the rhythmic bustle of a burgeoning business burg... especially when you're the one building it... | Read more »
Auroch Digital is Bringing Back Games Wo...
| Read more »
Blades of Brim is a New Endless Runner f...
SYBO Games, the minds behind the ever-popular Subway Surfers, have announced their latest project: Blades of Brim. [Read more] | Read more »
Carbo - Handwriting in the Digital Age...
Carbo - Handwriting in the Digital Age 1.0 Device: iOS Universal Category: Productivity Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Draggy Dead (Games)
Draggy Dead 1.1 Device: iOS Universal Category: Games Price: $.99, Version: 1.1 (iTunes) Description: Ditch your dead end job and take up a rewarding career in Grave Robbing today!Guide the recently deceased to a fun filled life of... | Read more »
Bad Dinos (Games)
Bad Dinos 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Apple Watch isn't Great as a Fi...
| Read more »
Show the World What You See With Stre.am...
Live broadcasting is getting popular on mobile devices, which is why you can now get Stre.am, by Infinite Takes. [Read more] | Read more »
PhotoTime's 2.1 Update Adds Apple W...
The latest PhotoTime update is adding even more functionality to the handy photo organizing app. Yep, including Apple Watch support. [Read more] | Read more »

Price Scanner via MacPrices.net

New 27-inch 3.3GHz 5K iMac in stock with free...
Adorama has the new 27″ 3.3GHz 5K iMac in stock today for $1999 including free shipping plus NY & NJ sales tax only. Adorama will include a free copy of Apple’s 3-year AppleCare Protection Plan. Read more
Memorial Day Weekend Sale: New 27-inch 3.3GHz...
Best Buy has the new 27″ 3.3GHz 5K iMac on sale for $1899.99 this weekend. Choose free shipping or free local store pickup (if available). Sale price for online orders only, in-store prices may vary... Read more
OtterBox Maximizes Portability, Productivity...
From the kitchen recipe book to the boarsroom presentation, the OtterBox Agility Tablet System turns tablets into one of the most versatile pieces of handheld technology available. Available now, the... Read more
Launch of New Car App Gallery and Open Develo...
Automatic, a company on a mission to bring the power of the Internet into every car, has announced the launch of the Automatic App Gallery, an app store for nearly every car or truck on the road... Read more
Memorial Day Weekend Sale: 13-inch 1.6GHz Mac...
Best Buy has the new 13″ 1.6GHz/128GB MacBook Air on sale for $849 on their online store this weekend. Choose free shipping or free local store pickup (if available). Sale price for online orders... Read more
Memorial Day Weekend Sale: 27-inch 3.5GHz 5K...
Best Buy has the 27″ 3.5GHz 5K iMac on sale for $2099.99 this weekend. Choose free shipping or free local store pickup (if available). Sale price for online orders only, in-store prices may vary.... Read more
Sale! 16GB iPad mini 3 for $349, save $50
B&H Photo has the 16GB iPad mini 3 WiFi on sale for $349 including free shipping plus NY sales tax only. Their price is $50 off MSRP, and it’s the lowest price available for this model. Read more
Price drop on 2014 15-inch Retina MacBook Pro...
B&H Photo has dropped prices on 2014 15″ Retina MacBook Pros by $200. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799.99 save $200 - 15″ 2.5GHz... Read more
With a Mission to Make Mobile Free, Scratch W...
Scratch Wireless, claiming to be the world’s first truly free mobile service, has announced the availability of a new Scratch-enabled Android smartphone, the Coolpad Arise. The smartphone is equipped... Read more
First-Ever Titanium Alloy Curved iPhone 6 Scr...
One of the most common problems with mobile phones is damage to the screens. The slightest drop can cause a dreaded spider web of gashes and cracks in the glass panel surface that can cost $hundreds... Read more

Jobs Board

*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* TV Live Streaming Frameworks Test En...
**Job Summary** Work and contribute towards the engineering of Apple 's state-of-the-art products involving video, audio, and graphics in Interactive Media Group (IMG) at 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
Partner Marketing Manager, Merchant- *Apple*...
**Job Summary** The Apple Pay partner marketing team is looking for a marketing manager to develop and drive US marketing programs with our merchant partners. The right Read more
Technical Project Manager - *Apple* Pay - A...
**Job Summary** Apple Pay is seeking an experienced technical PM to…manage the on boarding of new merchants for the Apple Pay platform in the US Within this role you Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.