Re: dirac(x) and heaviside(x)

[John W. Eaton]

On  7-Dec-2010, Jordi Gutiérrez Hermoso wrote:

| I wish we could make Octave aware of when a particular function exists
| in some 'Forge package, but this would require the tighter integration
| between core and 'Forge I've always wanted. A very frequent question
| in #octave is that people can't find this or that function. So far,
| I've been directing them to
| 
|      http://octave.sf.net/functions_by_alpha.php
| 
| but it would be nice if Octave itself at least knew about which
| functions are in 'Forge packages (and provided appropriate warnings
| about the quality or externality of 'Forge functions, if desired).
| 
| If I write functionality to do this, could the patch be accepted?

In the development version of Octave, we already have the
"missing_function_hook" and "unimplemented" functions, which together
provide this sort of thing:

  octave:1> foobar
  error: `foobar' undefined near line 1 column 1
  octave:1> ode45
  warning: Octave provides lsode for solving differential equations.  For more
  information try `help lsode'.  Matlab-compatible ODE functions are
  provided by the odepkg package.  See `http://octave.sf.net/odepkg/'.

  Please read `http://www.octave.org/missing.html' to learn how you can
  contribute missing functionality.


  error: `ode45' undefined near line 1 column 1

Currently this just prints a special message for core Matlab
functions.  Extending it for package functions would not be hard, but
who maintains the list of functions?

Do Matlab users typically not know that a function they are using
comes from a Matlab Toolbox(TM) instead of Matlab?  It does seem that
Octave users don't know that they are using functions from a package,
so I guess the answer is probably yes.

jwe