Re: Relative strengths: IDL vs. PV-Wave ?

[mcook(at)ti.com (Mark K. Cook)]

Martin,

I can't answer all of your questions, but I can relate my own
experiences for you to consider.  First of all we have site
licenses for PV-Wave on many of our computers here, so it
is more widespread than IDL.  I use IDL on a couple of projects
primarily because I want to use their ENVI package for spectral
remote sensing which is based on IDL.  I have used both IDL and
PV-Wave for my own uses however, and here are some of my 
observations:

* There isn't much difference as far as coding goes for the most 
  part.  For some reason, IDL seems to run faster for me, but
  that may be my particular applications.  Don't use me as
  a benchmark. 

* The main differences come from when the two products split
  from the common source and additions were made:  GUI and
  numerical/stat routines.  Review the two offerings yourself
  to compare their relative merits.

* I'm not crazy about the GUI for either.  If I have to make
  a GUI now, I will use a TCL/TK driver with PV-Wave as an
  engine (I haven't tried it with IDL, simply because I've
  never had to).  This opinion is primarily because I don't
  like messing with the intricacies of low-level widgets and
  the like.  Also they seem much less flexible than I like.

* Some of my work involves using polygon graphics.  PV-Wave
  has quite a few useful routines for polygon manipulation
  (both will render polygons) already included that really
  help here.  It is easy to write your own routines to mimic
  the PV-Wave routines in IDL however.

* The only bug I've noticed between the two was a consistently
  incorrect rendering from PV-Wave of a 3-D surface with shading.  
  IDL produced the correct rendering with essentially the same 
  code and was much faster about it.

* I've only done a little interfacing to other languages, with
  IDL, but didn't have much problem.  Again, it was only minor
  routines.

* I haven't noticed any difference for the image processing
  routines.

* I would surmise that you want your own code for the machine
  learning or NN applications.  I suspect your code would run
  on either about equally well.

* I was told there may be OpenGL support in a future version
  of IDL, which is something particularly useful to me.

* Even though PV-Wave is widespread here, I've noticed most
  engineers use MATLAB.  I firmly believe however that is 
  because they have little or no experience with PV-Wave.
  They don't realize the rich offerings Wave and IDL have
  for their work.


Hope this helps.  I don't think you'll go wrong with either.
If however you have need for a product like ENVI, I have 
found it very useful for my work and it isn't available for
PV-Wave.


Regards,
Mark Cook
mcook@ti.com


Dr. Mark K. Cook, MGTS
Systems Group
Texas Instruments, Inc.