[Octave-bug-tracker] [bug #55249] function ones does not always return a valid matrix

[Anders Lennartsson]

URL:
  <https://savannah.gnu.org/bugs/?55249>

                 Summary: function ones does not always return a valid matrix
                 Project: GNU Octave
            Submitted by: andersbertil
            Submitted on: Wed 19 Dec 2018 10:40:35 PM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Unexpected Error
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.4.1
        Operating System: GNU/Linux

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Details:

The function ones seems to return an object which is not always a matrix. 

With Octave 4.4.1-2~bpo9+1 running on Debian I can recreate the problem as
follows:

a=linspace(-2,2,6)
b=ones(length(a),1)
c=ones(1,length(a))
d=[1 1 1 1 1 1]
ff=zeros(1,length(a))


Everything looks fine, but checking the variables with an extended version of
paramdemo.cc, it turns out that c is not a matrix although a, b, d and ff
passes the test.

The code for paramdemo.cc is attached as a file. It was compiled with gcc
6.3.0 on Debian stretch by mkoctfile paramdemo.cc

Output for the 4 variables that are matrices is

Number of input arguments  : 1
Number of output arguments : 0
Argument is of type numeric.
  Argument is a matrix.
    Argument number of dimensions are : 2
    Dimension 0 is : 1
    Dimension 1 is : 6
    Number of ones : 1
    Chopping trailing singletons.
    Argument number of dimensions are : 2
    Number of ones : 1
    Chopping all singletons.
    Argument number of dimensions are : 2
    Number of ones : 1
    Dimension 0 is : 6
    Dimension 1 is : 1
    vector length is 6.
    Argument is vector: 1
    Argument length: 2
    Argument num_ones: 1
  real matrix
    vector length is 6.
    Argument is vector: 1
    Argument length: 2
    Argument num_ones: 1
Properties of input array:
  includes only int, Inf or NaN values
  includes only integers in [-10,10]



while output for the variable c is

Number of input arguments  : 1
Number of output arguments : 0
Argument is of type numeric.
Properties of input array:
  includes only int, Inf or NaN values
  includes only integers in [-10,10]


If c is added to zeros(1,length(a)) the result passes the test. 

As I do not see any use case for this behaviour, it seems this is a bug. 




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File Attachments:


-------------------------------------------------------
Date: Wed 19 Dec 2018 10:40:35 PM UTC  Name: paramdemo.cc  Size: 4KiB   By:
andersbertil

<http://savannah.gnu.org/bugs/download.php?file_id=45701>

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