bugGNU Octave - Bugs: bug #49576, ** On entry to ZLASCL parameter...

 
 

bug #49576: ** On entry to ZLASCL parameter number 4 had an illegal value

Submitter:  None
Submitted:  Fri 11 Nov 2016 03:15:20 AM UTC
   
 
Category:  Octave Function Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Fixed Assigned to:  None
Originator Name:  SFU Originator Email:  -email is unavailable-
Open/Closed:  * Closed Release:  * 4.0.0
Operating System:  * GNU/Linux Fixed Release:  None
Planned Release:  None
* Mandatory Fields

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Fri 11 Nov 2016 06:28:27 PM UTC, comment #2: 

Yes, I get the same BLAS error message as the OP with Octave 4.0.3, and with 4.2.0-rc4 the warning that Rik shows in comment #1 instead. I agree this looks like a misunderstanding about the division operator and not a bug.

Mike Miller <mtmiller>
Group Member
Fri 11 Nov 2016 04:21:09 AM UTC, comment #1: 

Under the soon to be released 4.2.0, I get the following warning


warning: matrix singular to machine precision
warning: called from
    func541 at line 74 column 8
    No541 at line 82 column 5


Line 74 is


    Fx = ((X / (log10(X - 1).^4)) - 3) ;


This shows you are trying to divide a matrix by another matrix.  Did you mean to use the operator './' instead which would divide each entry in X instead?

My guess is that you have something wrong in the code, rather than a problem with Octave itself.  You can use the debugger to step through your code to see what is happening.

Try


dbstop No541
No541
dbstep


Keep hitting return to step through the code line by line.  You can print out variables just by typing their name. 


Rik <rik5>
Group administrator
Fri 11 Nov 2016 03:15:20 AM UTC, original submission:  

I do homework, and I find error:
 ** On entry to ZLASCL parameter number  4 had an illegal value
error: func541: exception encountered in Fortran subroutine zgelsd_
error: called from
    func541 at line 74 column 8
    No541 at line 82 column 5
error: evaluating argument list element number 2
error: called from
    No541 at line 82 column 5

where

line 73   |function Fx = func541(X)
line 74   |    Fx = ((X / (log10(X - 1).^4)) - 3) ;
line 75   |end

line 81   |     X = -10:0.001:10 ;
line 82   |     plot(X,func541(X))

(It's in No541.m)
I don't now, where mistackes, maybe my code have mistackes.



double octave dropped without an error message.
(This was done no51.m program)


$ uname -a
Linux victor-Aspire-4520 4.4.0-45-generic #66-Ubuntu SMP Wed Oct 19 14:12:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
(LM 18 mate)

GNU Octave, version 4.0.0
Copyright (C) 2015 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  For details, type 'warranty'.

Octave was configured for "x86_64-pc-linux-gnu".

Anonymous

 

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Attach Files:
   
   
Comment:
   

Attached Files
file #38933:  No51.m added by None (7KiB - text/x-objcsrc)
file #38934:  No541.m added by None (4KiB - text/x-objcsrc)

 

Depends on the following items: None found

Items that depend on this one: None found

 

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  • -email is unavailable- added by mtmiller (Posted a comment)
  • -email is unavailable- added by rik5 (Posted a comment)
  • -email is unavailable- added by None (Submitted the item)
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    Follow 4 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-11-11 rik5 Open/ClosedOpen Closed
    2016-11-11 rik5 StatusNone Fixed
    2016-11-11 None Attached File- Added No51.m, #38933
        Attached File- Added No541.m, #38934

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