[Gmat-developers] Octave Instead of Matlab

[Steven H. <Ste...@na...>]

I've tried posting this to existing threads and it keeps failing, so 
I'll start a new thread with this.

Haisam,

     I recognize that Matlab is expensive software that not everyone has 
access to.  In fact, once I leave the office, I'm one of them... at home 
I can't use the Matlab interface.   In my opinion, there's a more 
important reason to minimize dependence on Matlab and that is 
performance.  The same could be said of Octave.  Many of the features 
we've implemented, or are currently implementing, are designed to 
minimize dependence on MATLAB:

1)   GMAT has an inline math capability that uses MATLAB's syntax.  This 
capability uses a math parser internal to GMAT to evaluate expressions 
so there is no need to use MATLAB.
2)   We are currently implementing a feature to write your own functions 
in GMAT.  This will be a very powerful new feature.
 3)   We are evaluating new optimizers so optimization does not require 
MATLAB's fmincon function.  I looked into Octave, and as of 6 months 
ago, it didn't have an open source optimizer.  While Octave supports 
optimization, you have to obtain proprietary software to use the feature.

    We currently don't have plans in the schedule to put in an Octave 
interface.  This is not because it would not be useful, rather, it's 
because with limited resources there are other features such as those 
above that are more beneficial to implement because they minimize 
dependence on any external software be it Matlab or Octave.  However, if 
someone in the community were to implement the interface, that would be 
great!

    I  have two concerns about Octave if the interface is implemented, 
and perhaps someone can lay them to rest.   The first regards 
stability.  I installed Octave on my laptop several months ago and found 
it very unstable.  I couldn't even edit a file without it crashing. 
Perhaps the recent stable release is ok.  Secondly, GMAT is used to 
support NASA flight projects, so, we have to be confident that if we use 
Octave, it is working correctly.  I don't have any experience with 
Octave so I don't know much about how it is validated, and what types of 
numerical issues it has.  Does anyone have any info they could point me to?