bugGNU Octave - Bugs: bug #49410, ode solvers use Hermitian...

 
 

bug #49410: ode solvers use Hermitian conjugate where ordinary transpose is desired

Submitted by:  Rik <rik5>
Submitted on:  Fri 21 Oct 2016 10:41:57 PM UTC  
 
Category:  Octave Function Severity:  3 - Normal
Priority:  5 - Normal Item Group:  None
Status:  Fixed Assigned to:  None
Originator Name:  Open/Closed:  Closed
Release:  4.2.0-rc2 Operating System:  Any

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Sun 23 Oct 2016 10:15:19 AM UTC, comment #6:

Thanks, you are to fast for me :)

Sebastian <sschoeps>
Sun 23 Oct 2016 03:34:00 AM UTC, comment #5:

I changed the additional instances I found in comment #4 and then checked in all of the changes here (http://hg.savannah.gnu.org/hgweb/octave/rev/6b134d294d61).

Rik <rik5>
Project Administrator
Sat 22 Oct 2016 08:34:01 PM UTC, comment #4:

Seems correct. What about these additional instances in ode_event_handler?

private/ode_event_handler.m:91: evt = evt(:)'; term = term(:)'; dir = dir(:)';
private/ode_event_handler.m:118: ynew = (y - (t - tnew) * (y - yold) / (t - told))';
private/ode_event_handler.m:145: evtold = evtold(:)'; told = t; yold = y;

Rik <rik5>
Project Administrator
Sat 22 Oct 2016 08:16:24 PM UTC, comment #3:

A patch for this is attached.
It also adds a test in both ode23 and ode45.
I also spotted an additional instance in
runge_kutta_inerpolate.m.

(file #38796)

Carlo de Falco <cdf>
Project Member
Sat 22 Oct 2016 07:27:05 PM UTC, comment #2:

As further confirmation consider the following example

[sol] = ode45 (@(t, x) 1, [0 1], 1i);

the exact solution should be

sol.y = 1i + sol.x

but the actual solution has the wrong sign for the imaginary part.

Carlo de Falco <cdf>
Project Member
Sat 22 Oct 2016 06:30:42 AM UTC, comment #1:

@Rik

I think this should all be .' and not '

c.

Carlo de Falco <cdf>
Project Member
Fri 21 Oct 2016 10:41:57 PM UTC, original submission:

Attached is a list of the Hermitian conjugates used in the scripts/ode directory.

@Sebastion: If you could take a look at each instance and decide whether ' or .' is appropriate that would be great.

ode23.m:236: solution.x(end,:)', "done", odeopts.funarguments{:});
ode23.m:259: varargout{1}.x = solution.t'; # Time stamps are saved in field x (row vector)
ode23.m:260: varargout{1}.y = solution.x'; # Results are saved in field y (row vector)
ode45.m:227: solution.x(end,:)', "done", odeopts.funarguments{:});
ode45.m:250: varargout{1}.x = solution.t'; # Time stamps are saved in field x (row vector)
ode45.m:251: varargout{1}.y = solution.x'; # Results are saved in field y (row vector)
private/ode_event_handler.m:91: evt = evt(:)'; term = term(:)'; dir = dir(:)';
private/ode_event_handler.m:118: ynew = (y - (t - tnew) * (y - yold) / (t - told))';
private/ode_event_handler.m:145: evtold = evtold(:)'; told = t; yold = y;
private/runge_kutta_interpolate.m:25: u_interp = interp1 (z, u', t, "linear");

Rik <rik5>
Project Administrator

 

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Attached Files
file #38796:  open_l3DBTYkm.txt added by cdf (4KiB - text/plain)

 

Depends on the following items: None found

Items that depend on this one: None found

 

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    Follow 5 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-10-23 rik5 StatusPatch Submitted => Fixed
        Open/ClosedOpen => Closed
    2016-10-22 cdf StatusConfirmed => Patch Submitted
    2016-10-22 cdf Attached File- => Added open_l3DBTYkm.txt, #38796
    2016-10-21 rik5 Carbon-Copy- => Added sschoeps

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