TITLE: Increasing precision of Octave
QUESTION [17 upvotes]: I notice the values I get from octave are rounded to 5 decimal places. How can I increase that to 6 or 8 for example?

REPLY [14 votes]: The real answer was never posted to this and I ended up here while trying to find it. The output_precision command is what you want. Setting format long provides much more than the requested amount of precision. That may be okay, but if you want a specific precision, use output_precision instead.
>> help output_precision
'output_precision' is a built-in function from the file libinterp/corefcn/pr-output.cc

 -- VAL = output_precision ()
 -- OLD_VAL = output_precision (NEW_VAL)
 -- output_precision (NEW_VAL, "local")
     Query or set the internal variable that specifies the minimum
     number of significant figures to display for numeric output.

     When called from inside a function with the "local" option, the
     variable is changed locally for the function and any subroutines it
     calls.  The original variable value is restored when exiting the
     function.

     See also: format, fixed_point_format, output_max_field_width.

Additional help for built-in functions and operators is
available in the online version of the manual.  Use the command
'doc <topic>' to search the manual index.

Help and information about Octave is also available on the WWW
at http://www.octave.org and via the help@octave.org
mailing list.
>> output_precision
ans =  15
>> output_precision(7)
>> a = [1 4.4 4.4^2 4.4^3 4.4^4 4.4^5;]
a =
      1.000000      4.400000     19.360000     85.184000    374.809600   1649.162240
>> output_precision(4)
>> a = [1 4.4 4.4^2 4.4^3 4.4^4 4.4^5;]
a =                                                                                                                                                     
      1.0000      4.4000     19.3600     85.1840    374.8096   1649.1622