From bug-octave-request at che dot utexas dot edu  Mon Dec  5 07:32:58 1994
Subject: OCTAVE: Bug - Report
From: nowottny at mathematik dot uni-stuttgart dot de (Dietrich Nowottny)
To: bug-octave at che dot utexas dot edu
Date: Mon, 5 Dec 1994 14:32:46 +0100


Octave - Version: 1.0

Machine:          IBM Risc 6000

Operating System: AIX 3.2.5


--------------------------------------------

1.) BUG-Report
==============

The problem (which did NOT arise with Octave 0.82) is about
     Inf, NaN and division by zero.

Example:

octave:1> 1/0
error: division by zero attempted
error: evaluating binary operator `/' near line 1, column 2
octave:2> NaN
error: `NaN' undefined near line 2 column 1
error: evaluating expression near line 2, column 1
octave:3> Inf
Inf = Inf
octave:4> a=Inf, b=Inf, a/b
a = Inf
b = Inf
ans = 1

I just can't imagine that such faults arise in a new version which worked
correctly in old versions. But what could cause these problems?


--------------------------------------------

2.) Suggestion to OCTAVE-Syntax
===============================

Suggestion: Indexing matrices with one index only

Having used MATLAB for quite a long time, I found it useful to make
matrices behave like a column-vector of its columns.

Example: A = 1 3 5     => A(1)=1, A(4)=3, A(8)=7, ...
             2 4 7
             6 8 0
         v = A(:)      => v = [1 2 6 3 4 8 5 7 0]'
         B = zeros(3,3)
         B(:) = v      => B = 1 3 5
                              2 4 7
                              6 8 0

In my opinion this does not contradict the theory of indexing matrices
with two indices only, because column- or row-vectors can be looked at
as special (n,1)- or (1,n)-Matrices - and it is possible to evaluate v(1)!

I would be very pleased if this topic would be changed in the OCTAVE
syntax in later versions.


--------------------------------------------

I'm looking forward for your answer. Thank you very much in advance !

Dietrich Nowottny