bugGNU Octave - Bugs: bug #41268, symbolic package: heaviside...

 
 

bug #41268: symbolic package: heaviside function is not implemented

Submitter:  None
Submitted:  Sat 18 Jan 2014 08:08:52 AM UTC
   
 
Category:  Octave Package Severity:  1 - Wish
Priority:  5 - Normal Item Group:  Feature Request
Status:  Fixed Assigned to:  None
Originator Name:  Borys Niekurzak Originator Email:  -email is unavailable-
Open/Closed:  * Closed Release:  * dev
Operating System:  * Any Fixed Release:  None
Planned Release:  None
* Mandatory Fields

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Sun 22 Feb 2015 06:24:58 AM UTC, comment #2: 

This appears to be fixed in the new symbolic package.

Mike Miller <mtmiller>
Group Member
Sun 19 Jan 2014 06:29:52 PM UTC, comment #1: 

This is because the heaviside function in Octave is a numerical implementation, not a symbolic implementation as it is in Matlab. Retitling this bug as a feature request to implement this function symbolically.

Please note that the symbolic package is largely unmaintained and needs a lot of work. See the following links.

Mike Miller <mtmiller>
Group Member
Sat 18 Jan 2014 08:08:52 AM UTC, original submission:  

Dear Developers :)

I hope I do not duplicate the bug.

The following code from my university classes, which worked on MATLAB 13, produces an error on octave:


t=sym('t')
w=sym('w')

a=2;
A=2;
t0=0;

f=A.*heaviside(t-(t0-a/2)) - A.*heaviside(t-(t0+a/2));info
F=fourier(f,t,w);


It gives the following error:


error: cast: type name `sym' is not a built-in type
error: called from:
error:   /usr/share/octave/3.6.2/m/miscellaneous/cast.m at line 36, column 9
error:   /usr/share/octave/packages/specfun-1.1.0/heaviside.m at line 39, column 5
error:   /home/borys/politechnika/3 semestr/sygnaƂy/4/prostokat.m at line 12, column 2


Line 12 is where the heaviside function is called.

Even the simplest commend, which I suppose would work on matlab (I am not a MATLAB expert yet, I just started learning, so I am not 100% sure) for example:

x=sym('x')
heaviside(x)


gives the same error.

Anonymous

 

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    Follow 8 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2015-02-22 mtmiller StatusConfirmed Fixed
        Open/ClosedOpen Closed
    2014-01-19 mtmiller Severity3 - Normal 1 - Wish
        Item GroupMatlab Compatibility Feature Request
        StatusNone Confirmed
        Release3.6.2 dev
        Operating SystemGNU/Linux Any
        Summaryheaviside function does not work with sumbolic variables symbolic package: heaviside function is not implemented

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