troubles with remez

[Dan McMahill]

Hello,

I'm using octave-3.2.4 and signal-1.0.10.  I'm having problems getting 
the remez() function to work and give reasonable answers.

The filter I'm trying to do should be fairly simple.  It is just 
something which has a prescribed amplitude vs freq rolloff over about 
15% of the Nyquist band.  I'm only asking for a fairly low order (less 
than 10) filter.  It seems I can easily get "error: remez: insufficient 
extremals" and also fairly easily get "warning:  remez:  --failed to 
converge -- returned filter may be bad.".

The same code runs fine under matlab.

For example

b = remez(7, ...
   [0.0  0.24 0.25 0.35 0.36 1.0], ...
   [1.0  1.0  1.0  0.7  0.7  0.0], ...
   [0.01      1.0       0.01])

gives the too many extremals where matlab gives a filter which matches 
the desired slope over the 0.25 to 0.35 band.

b = remez(6, ...
   [0.0  0.24 0.25 0.35 0.36 1.0], ...
   [1.0  1.0  1.0  0.7  0.7  0.0], ...
   [0.01      1.0       0.01])

gives the failed to converge.

on matlab, I also get a filter which matches the requested response over 
the 0.25 to 0.35 band.

am I doing something wrong or is the octave remez() just in need of a 
little work?

Thanks
-Dan