Program Translation - Nov. 14, 2013

[Gordon Sande]

On 2013-11-14 17:07:45 +0000, mecej4 said:

> On 11/14/2013 8:18 AM, E.D.G. wrote:
>> Posted by E.D.G.  on November 14, 2013
>> 
>> In view of the fact that I mentioned the following project in
>> both Perl and Python Newsgroup notes and did not get any hostile
>> responses I am going to take a chance and mention it again in all three
>> of these Newsgroups.  People posting responses might want to do that in
>> just one Newsgroup.  I will check all three for responses for a few weeks.
>> 
>> 
>> This is the Web address for an interesting and apparently unique
>> computer program written using FORTRAN 77.  As far as I am aware, it has
>> never been translated to newer language.  There is a BASIC version that
>> was apparently written around the same time as the FORTRAN version.
>> 
>> http://www.bfo.geophys.uni-stuttgart.de/etgtab.html
>> 
>> What a number of us would like to do is obtain a copy of the
>> program that is written in a newer language so that we can then merge it
>> with the programs available through the following Web page.  The new
>> programs would then be made available as freeware programs to
>> researchers around the world. This indirect link is being used in an
>> effort to keep Web site related spam to a minimum.  I don't collect
>> credits by having people visit that (indirect) Web site.
>> 
>> http://www.freewebs.com/eq-forecasting/RH.html
>> 
>> If there are any programmers who might be interested in such a
>> translation effort then I would be interested in hearing from them.
>> 
>> Etgtab generates Solid Earth Tide and ocean tide data for any
>> location on or inside the planet.  I am not aware of any other freeware
>> program that can do that.
>> 
>> SunGP available at that second Web site is the only freeware
>> program that I know about that generates what are sometimes referred to
>> as subsolar and sublunar types of data.  The download code was written
>> using True BASIC.
>> 
>> If you draw a line between the centers of the sun and the Earth
>> then the place where that line crosses the surface of the Earth is the
>> subsolar location.  The sublunar location is the same type of thing.
>> The SunGP program code is also available in Perl code, but not through
>> any Web sites.
>> 
>> 
> If this old program is to be translated or reused, do use this 
> opportunity to fix some bugs in the program.
> 
> The data file contains data for 1200 waves, but the program computes 
> results for 1212 waves. For waves 1201 to 1212, the program ends up 
> calculating results based on uninitialized data. Whether or not this 
> affects the validity of the final output results is something that 
> someone knowledgeable about the field of application has to judge.
> 
> -- mecej4

Indeed! Under NAGWare Fortran it runs to completion with C=all but pulls an
undefined reference when C=undefined is added.

Lots of obsolete features and other warnings but no compiler error messages.

The obvious lessons are that 1. Fortran has very good historical continuity
and 2. the good debugging Fortran compilers do a good job.