norm problem

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

norm problem

Ludger Leushacke

Hello again !

Thanks for your prompt and accurate answer to my help request.
Some comments:

:: My problem is that Octave first calls the functions and
:: collects all text for screen output and displays it after all
:: calculations have been finished.

:There are two possible solutions.  You can turn paging off completely
:by setting the variable page_screen_output to the string "false", or
:you can force the output buffer to be flushed to the pager at any time
:by using the command fflush (stdout).  For an example of this, look at
:the menu function (it's implemented as an M-file).
:Let me know if this isn't what you want, or it doesn't work quite the
:way you expect.

This is exactly what I meant. The simplest solution is to set
page_screen_output="false".


:: - The function norm(A,"fro") seems to work not correctly in
::   every case

:Can you send a specific case that fails?

If A is a scalar or vector, octave gives
error: failed to convert `fro' to a numeric type -- default
       conversion turned off
In principle this might be correct, since the F-norm of a scalar or
vector makes no sense. But from the definition of the F-norm
sqrt(sum(diag(A'*A))) it should work and really does. MATLAB
reports no error (I guess "fro" is ignored for scalars and vectors).
I think you want to avoid overhead in your functions, but a simple
check of input dimensions could help.

A last question: What is the search hirarchy for commands in octave?
(internal command, octave library m-file, m-file in current directory, ...)

Thank you very much again

Ludger

-------------------------------------------------------------------------
Dr. Ludger Leushacke
Research Establishment for Applied Science (FGAN)
Research Institute for High Frequency Physics (FHP)
Neuenahrer Str. 20
D-53343 Wachtberg-Werthhoven, Germany
phone:  049-228-852-261
e-mail: [hidden email]