[sage-support] Re: feature request - worksheets labels.
On 1 Lut, 00:34, William Stein wrote: > 2010/1/31 Kakaz : > > > I have several worksheets in my sage, and when I have some new ideas I > > create other one, somethimes just for fun. So there are worksheets > > named: "Idea 1", "Matrices", 'FFT", "FFT3" etc. After a month I do not > > remember what is inside. Of course I may open them and check, but I > > thing that there should be something better to depict my worksheets. > > Folders would be interesting in order to do that, but in fact I mean > > something like labels. > > > Like "comments" in Excel - something what You see, when You point with > > mouse cursor to worksheet name, and what normally is not visible, You > > only see it, when You stay with cursor on worksheet name for example > > for 1 second, without clicking, or entering workseet. > > I thought it would be useful, because You do not have to open > > worksheet in order to have an idea what is inside... > > As a temporary workaround you might note the following: > > (1) From the home screen (the list of all worksheets), you can do a > fulltext search of the *contents* of all worksheets by typing a list > of words in the upper right text box and clicking "Search Worksheets". > > (2) You could put text in the worksheets themselves such as > "label:foo" or something, then search for label:foo to find only such > worksheets. > > William Thanks a lot! I have a habit to name worksheet with long names, which is enough for me right now. But I suppose, when You have several fields of activity, some examples imported from web etc. having labels would be very useful feature, and I suppose developing effort would be not so high to get this. Best Regards Kazek -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: feature request
Thanks, I think I'll do both: ask for an account, so that I can report bugs, and post about my feature request here (I'll open a new thread, so that the subject will be informative) Flávio On 7 abr, 16:20, davidloeffler wrote: > Hi Flavio, > > You can have a trac account if you like -- it's only as an anti-spam > measure that we require a login. Just email Michael Abshoff (address > on the trac front page). It's possible to create new tickets for > feature requests; these should be allocated to the milestone "sage- > wishlist". > > That said, it's a better idea to post your request here on sage- > support. That way, more Sage developers will see it, and might be > inspired to implement the feature you're after; and if the feature > does exist, but in a nonobvious way, we can point you to where to find > it. > > David > > On Apr 7, 2:29 pm, Flavio Coelho wrote: > > > Hi, > > > what is the official channel for feature requests? > > I checked the trac site but the ticket system doesn't allow anonymous > > users to create new tickets. > > > thanks, --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request
Hi Flavio, You can have a trac account if you like -- it's only as an anti-spam measure that we require a login. Just email Michael Abshoff (address on the trac front page). It's possible to create new tickets for feature requests; these should be allocated to the milestone "sage- wishlist". That said, it's a better idea to post your request here on sage- support. That way, more Sage developers will see it, and might be inspired to implement the feature you're after; and if the feature does exist, but in a nonobvious way, we can point you to where to find it. David On Apr 7, 2:29 pm, Flavio Coelho wrote: > Hi, > > what is the official channel for feature requests? > I checked the trac site but the ticket system doesn't allow anonymous > users to create new tickets. > > thanks, --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request ...
On Apr 3, 3:15 am, Georg <[EMAIL PROTECTED]> wrote: > > exponentiation, > i don't konw if this is implemented or a topic here, but there exists also the logarithm of a matrix. h --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request ...
Hello, > sage: r = matrix(SR, 4, 4, [[21,17,6,8], [-5,-1,-6,-3], [4,4,16,2], > [2,3,-4,-1]]) > sage: r.exp() > . This is happening since Maxima is failing to do the computation for reasons that I don't know. I suppose it wouldn't be too difficult to write our own matrix exponentiation. --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request ...
> sage: matrix(SR, 3, 3, [[21,17,6],[-5,-1,-6],[4,4,16]]).exp() > > [ (13*e^16 - e^4)/4 (13*e^16 - 5*e^4)/4 (e^16 - e^4)/2] > [ (e^4 - 9*e^16)/4 (5*e^4 - 9*e^16)/4 (e^4 - e^16)/2] > [ 4*e^16 4*e^16e^16] > this does not work for 4x4 matrices, try sage: r = matrix(SR, 4, 4, [[21,17,6,8], [-5,-1,-6,-3], [4,4,16,2], [2,3,-4,-1]]) sage: r.exp() . Georg --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request ...
Georg wrote:
> Thank you for the fast answer Mike,
>
>> What functionality did you envision having in a symmetric matrix class?
>>
>
> In general (not specific to the hermitian (symmetric) property)
> exponentiation,
> determinate,
> elementary matrix operations:
> - changing rows(colums)
> - multiplication of specific rows(colums) with a scalar
> - adding one row(colum) to another
> .i.e. simmilar transformations
> and one command for doing both in each case, i.e
> - changing row i with row j and additionally changing colum i with
> colum j
> - multiplying of row i with a scalar \lambda and additionally
> multiplying colum i with \bar{\lambda} (conjugated)
> - adding row i to row j and additionally adding colum i to j
> i.e. kongruent transformations (I'm not sure now if this is the
> right notation)
> , this may be useful for educational purposes (proofs in basic linear
> algebra)
>
There is some work going on right now to make assigning a column or row
much easier and more natural (so it will be about as easy as matlab is).
Thanks,
Jason
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[sage-support] Re: feature request ...
Thank you for the fast answer Mike,
>
> What functionality did you envision having in a symmetric matrix class?
>
In general (not specific to the hermitian (symmetric) property)
exponentiation,
determinate,
elementary matrix operations:
- changing rows(colums)
- multiplication of specific rows(colums) with a scalar
- adding one row(colum) to another
.i.e. simmilar transformations
and one command for doing both in each case, i.e
- changing row i with row j and additionally changing colum i with
colum j
- multiplying of row i with a scalar \lambda and additionally
multiplying colum i with \bar{\lambda} (conjugated)
- adding row i to row j and additionally adding colum i to j
i.e. kongruent transformations (I'm not sure now if this is the
right notation)
, this may be useful for educational purposes (proofs in basic linear
algebra)
specific to the hermitian (symmetric) case:
- diagonalization
- trace (which must be real then),
- check for definitness, i.e. something like is_positiv,
is_semipositiv, is_indefinite, is_definite (positive or
negativ), ..
(- associated quadratic (hermitian) form as a function in 2
vectorvalued variables), this is easy to workaround, just x^T A y
.
.
Georg
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[sage-support] Re: feature request ...
Hi Georg, There is currently support for taking the matrix exponential of a symbolic matrix already in Sage since it is using Maxima in the background. I suppose that this should be extended to other types of matrices. sage: matrix(SR, 3, 3, [[21,17,6],[-5,-1,-6],[4,4,16]]).exp() [ (13*e^16 - e^4)/4 (13*e^16 - 5*e^4)/4 (e^16 - e^4)/2] [ (e^4 - 9*e^16)/4 (5*e^4 - 9*e^16)/4 (e^4 - e^16)/2] [ 4*e^16 4*e^16e^16] What functionality did you envision having in a symmetric matrix class? --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: feature request/proposal concerning the method nearby_rational
John,
> A variation of this, which would be useful in some elliptic curve
> calculations, would be a function
> RR(x).nearby_rational_whose_denominator_is_a_perfect_square().
>
> For either problem, is there a better solution than going through the
> continued fraction convergents until one is found which has the
> required property? I hope so, since as I wrote that I could see that
> this would certainly fail on most inputs
the answer is yes. You want to find small integer solutions of
q^2*x - p = small, or if you write x=y/z, q^2*y - p*z = r with p,q,r small
(here y and z are known integers, and p,q,r are the unknowns).
Or modulo z: q^2*y = r (mod z) with r small. There are algorithms from
Coppersmith to find small roots of such modular equations.
The main idea is to build a lattice which contains (polynomial) multiples
of the equation to solve, to reduce the lattice (using LLL), and then one
obtains a set of polynomial equations with small coefficients, whose roots
modulo z necessarily are also roots over the integers.
@InProceedings{Coppersmith96b,
author = {Don Coppersmith},
title ={Finding a Small Root of a Univariate Modular Equation},
booktitle ={Proceedings of Eurocrypt'96},
pages ={155--165},
year = 1996,
volume = 1070,
series = lncs,
publisher =sv
}
@InProceedings{Coppersmith01,
author = {Don Coppersmith},
title ={Finding Small Solutions to Small Degree Polynomials},
booktitle ={Proceedings of CALC'01},
pages ={20--31},
year = 2001,
volume = 2146,
series = lncs,
publisher =sv
}
Paul
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[sage-support] Re: feature request/proposal concerning the method nearby_rational
A variation of this, which would be useful in some elliptic curve calculations, would be a function RR(x).nearby_rational_whose_denominator_is_a_perfect_square(). For either problem, is there a better solution than going through the continued fraction convergents until one is found which has the required property? I hope so, since as I wrote that I could see that this would certainly fail on most inputs John On 31/01/2008, Georg <[EMAIL PROTECTED]> wrote: > > Hi, > there is a method > RR(x).nearby_rational(...) > which returns a rational number > it would be convenient for me to have a method which returns a > rational number which has also a rational square root, something like > RR(x).nearby_rational_perfect_square(...) > , I'm not asking for a workaround, at least not for the most obvious > one (taking the square root of x and using .nearby_rational with > adjusted tolerance...), > may this method could be useful for others, too > Thanks, Georg > > > > > -- John Cremona --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
