[sage-support] Correctness of Extended Quadratic Residue Code over GF(4)
Hi, I'm working on vectors of varying sizes on GF(4) and I'm currently trying to implement the code given in http://www.iks.kit.edu/home/grassl/codetables/BKLC/BKLC.php?q=4n=8k=2 The first step (Extend the QRCode over GF(4) of length 11) should give me a [12, 6, 6] linear code - vectors of length 12, dimension 6, minimum (Hamming) distance 6. But the execution sage: codes.ExtendedQuadraticResidueCode(11, GF(4,'a')) Linear code of length 12, dimension 11 over Finite Field in a of size 2^2 gives me a linear code of dimension 11. If my field size is prime, then I do get a code with dimension 6. According to that source, the dimension should be 6 with field size 4 as well. Why isn't it? I'm running Sage Version 6.1.1, Release Date: 2014-02-04 on Ubuntu 12.04. Thank you in advance, Gerli -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
Re: [sage-support] Correctness of Extended Quadratic Residue Code over GF(4)
On Mon, Mar 24, 2014 at 6:28 AM, Gerli Viikmaa gerliviik...@gmail.com wrote: Hi, I'm working on vectors of varying sizes on GF(4) and I'm currently trying to implement the code given in http://www.iks.kit.edu/home/grassl/codetables/BKLC/BKLC.php?q=4n=8k=2 The first step (Extend the QRCode over GF(4) of length 11) should give me a [12, 6, 6] linear code - vectors of length 12, dimension 6, minimum (Hamming) distance 6. But the execution sage: codes.ExtendedQuadraticResidueCode(11, GF(4,'a')) Linear code of length 12, dimension 11 over Finite Field in a of size 2^2 gives me a linear code of dimension 11. If my field size is prime, then I do get a code with dimension 6. According to that source, the dimension should be 6 with field size 4 as well. Why isn't it? Quadratic residue codes are defined over prime fields: http://en.wikipedia.org/wiki/Quadratic_residue_code If there is a generalization of QR codes to the extension field case, it is not implemented in Sage. Sorry. Feel free to implement it and submit a patch:-) (Alternatively, share your code on sage-devel.) I'm running Sage Version 6.1.1, Release Date: 2014-02-04 on Ubuntu 12.04. Thank you in advance, Gerli -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
Re: [sage-support] Correctness of Extended Quadratic Residue Code over GF(4)
Hi, Thank you for your reply. I will look into the implementation of QR codes over non-prime fields. All the best, Gerli esmaspäev, 24. märts 2014 12:54.29 UTC+2 kirjutas David Joyner: On Mon, Mar 24, 2014 at 6:28 AM, Gerli Viikmaa wrote: Hi, I'm working on vectors of varying sizes on GF(4) and I'm currently trying to implement the code given in http://www.iks.kit.edu/home/grassl/codetables/BKLC/BKLC.php?q=4n=8k=2 The first step (Extend the QRCode over GF(4) of length 11) should give me a [12, 6, 6] linear code - vectors of length 12, dimension 6, minimum (Hamming) distance 6. But the execution sage: codes.ExtendedQuadraticResidueCode(11, GF(4,'a')) Linear code of length 12, dimension 11 over Finite Field in a of size 2^2 gives me a linear code of dimension 11. If my field size is prime, then I do get a code with dimension 6. According to that source, the dimension should be 6 with field size 4 as well. Why isn't it? Quadratic residue codes are defined over prime fields: http://en.wikipedia.org/wiki/Quadratic_residue_code If there is a generalization of QR codes to the extension field case, it is not implemented in Sage. Sorry. Feel free to implement it and submit a patch:-) (Alternatively, share your code on sage-devel.) I'm running Sage Version 6.1.1, Release Date: 2014-02-04 on Ubuntu 12.04. Thank you in advance, Gerli -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] int() on real numbers broken?
I am working on a Z80 project and I needed 72 bits of precision for 64 elements of the form log2(1+2^-i) (so log2(3/2), log2(5/4),...). I needed to convert these to hexadecimal, and it worked until I tried the following for i=56: int(256*log(1+2^-56,2)) This returns 1, when in fact it should be 0. Actually, instead of multiplying by 256, multiplying by 65536, or 600, or many other numbers would also return the integer part as 1. As a note, I used RealField(80) as my precision. -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] question
Is anyone there? I am trying to get sage to understand latex input. I get an error saying that pdflatex is not installed. How do I do this on a Mac? I have texlive and texshop installed. -Walter Wilcox -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] xlrd, xlwt, xlutils with sage
Hello everyone I want to use xlrd, xlwt, xlutils with sagemath. I have installed them in my system's Python but sage environment is not recognizing them. Any idea how can I make them work inside sage?? I am using Ubuntu 12(quantal) with 32 bits and Sage Version 5.8 with Python 2.7.5 Got same problem with Tkinter too but solved it using sudo apt-get install tk8.5-dev got solution form http://www.sagemath.org/doc/faq/faq-usage.html#how-to-get-sage-s-python-to-recognize-my-system-s-tcl-tk-install But what for other libraries? I tried to install them manually inside /usr/lib/sagemath/local/lib/python2.7/site-packages/ folder by putting tar files then extract them and then sudo python setup.py install but still not working -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
Re: [sage-support] question
On Mon, Mar 24, 2014 at 10:05 AM, Wilcox, Walter walter_wil...@baylor.edu wrote: Is anyone there? I am trying to get sage to understand latex input. I get an error saying that pdflatex is not installed. How do I do this on a Mac? I have texlive and texshop installed. I'm not sure what you mean. Can you give an example of the input and expected output? -Walter Wilcox -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Re: extension de corps
Bonjour, Il est malheureusement un peu problématique de construire des tours (extensions successives) de corps. Sage sait bien vérifier que votre F6 est un corps, mais F6 est toujours représenté comme anneau quotient et non comme corps fini ; c'est pourquoi certaines opérations naturelles ne marchent pas. Une solution possible est de commencer par construire F12 et de voir les autres corps comme des sous-corps de F12. Un calcul montre que le polynôme minimal de l'élément primitif w de F12 est x^12 - 2x^6 + 2. On peut maintenant faire sage: t=-(2^62 + 2^55 +1) sage: p=36*t^4+36*t^3+24*t^2+6*t+1 sage: F=GF(p) sage: R.x = PolynomialRing(F) sage: f = x^12 - 2*x^6 + 2 sage: F12.w = FiniteField(p^12, modulus=f) sage: v = w^2 sage: i = v^3 - 1 sage: i^2 == -1 True En principe, il est possible de construire explicitement les sous-corps et les plongements F2 - F6 - F12, mais il est sans doute plus facile de faire tous les calculs directement dans F12. Peter بتاريخ الأربعاء، 19 مارس، 2014 UTC+1 9:26:58 م، كتب ghamma...@gmail.com: Bonsoir SVP, j'ai besoin de definir sur Sage 3 extensions de corps, mais je n'arrive pas. Je peux definir que deux extensions. When i find the test F6.is field() the answer is true, in this representation i have Fp^2, Fp^6 and Fp^12 are fields. But I need that Fp^2 be a field extension bacause I need to seperate his elements(a in Fp^2=a0+i*a1 and i need the value of a0=a[0] and a1=a[1]) #t=2^62-2^54+2^44 t=-(2^62 + 2^55 +1) #t=2^63-2^49 p=36*t^4+36*t^3+24*t^2+6*t+1 r=36*t^4+36*t^3+18*t^2+6*t+1 tr=6*t^2+1 #-- Fp-- F=GF(p) #--- b=2 #--Fp^2-- K2.x=PolynomialRing(F) F2.i=FiniteField(p^2,modulus=x^2+1) # #-Fp^6- K6.y=PolynomialRing(F2) F6.v=F2.extension(y^3-i-1) #- #---Fp^12--- K12.z=PolynomialRing(F6) F12.w=F6.extension(z^2-v) F12.is_field=lambda:True # -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Re: int() on real numbers broken?
Hello, I am working on a Z80 project and I needed 72 bits of precision for 64 elements of the form log2(1+2^-i) (so log2(3/2), log2(5/4),...). I needed to convert these to hexadecimal, and it worked until I tried the following for i=56: int(256*log(1+2^-56,2)) This returns 1, when in fact it should be 0. Actually, instead of multiplying by 256, multiplying by 65536, or 600, or many other numbers would also return the integer part as 1. As a note, I used RealField(80) as my precision. Typing log(1 + 2^-56, 2) gives the result as a symbolic expression, not as an element of a real field. Applying int() to this internally uses a RealIntervalField with 53 bits of precision, which is not enough in this case. Here is a way to get the desired precision: sage: x = RealField(80)(256*log(1+2^-56,2)) sage: x 5.1254824061038682620123e-15 sage: int(x) 0 Peter -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Polynomial division without remainder
Working in a stack of multivariate polynomial rings, how can I compute the quotient of two polynomials in those cases where I know the remainder to be zero? Reading the docs I found two likely approaches, but neither seems to work as I'd have hoped. See below for error messages. Example: sage: PR1.a,b=QQ[] sage: PR2.x,y=PR1[] sage: n=(x-y)*(x+3*y) sage: d=(x-y) sage: n/d (x^2 + 2*x*y + (-3)*y^2)/(x - y) sage: PR2(n/d) --- TypeError Traceback (most recent call last) ipython-input-6-cc8d100cc210 in module() 1 PR2(n/d) …/sage/rings/polynomial/multi_polynomial_ring.pyc in __call__(self, x, check) 449 return x.numerator() 450 else: -- 451 raise TypeError, unable to coerce since the denominator is not 1 452 453 elif is_SingularElement(x) and self._has_singular: TypeError: unable to coerce since the denominator is not 1 sage: n.quo_rem(d) --- TypeError Traceback (most recent call last) ipython-input-7-d17781c77d90 in module() 1 n.quo_rem(d) …/sage/structure/element.so in sage.structure.element.NamedBinopMethod.__call__ (sage/structure/element.c:24924)() …/sage/rings/polynomial/multi_polynomial_element.pyc in quo_rem(self, right) 1730 return self.quo_rem(right) # this looks like recursion, but, in fact, it may be that self, right are a totally new composite type 1731 R = self.parent() - 1732 R._singular_().set_ring() 1733 X = self._singular_().division(right._singular_()) 1734 return R(X[1][1,1]), R(X[2][1]) …/sage/rings/polynomial/polynomial_singular_interface.pyc in _singular_(self, singular) 213 return R 214 except (AttributeError, ValueError): -- 215 return self._singular_init_(singular) 216 217 def _singular_init_(self, singular=singular_default): …/sage/rings/polynomial/polynomial_singular_interface.pyc in _singular_init_(self, singular) 229 230 if not can_convert_to_singular(self): -- 231 raise TypeError, no conversion of this ring to a Singular ring defined 232 233 if self.ngens()==1: TypeError: no conversion of this ring to a Singular ring defined -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Re: xlrd, xlwt, xlutils with sage
Here's the answer I just posted to your question on Stack Overflow (http://stackoverflow.com/questions/22612301/xlrd-xlwt-with-sagemath): Rather than installing them with the system Python, install them with Sage's Python: you can either do sage --sh: this starts a subshell with various environment variables set appropriately for use with Sage, in particular $PATH will have $SAGE_ROOT/local/bin first. Then install the packages with python setup.py install etc. Or you can just run Sage's Python directly with sage --python setup.py install -- John On Monday, March 24, 2014 7:07:23 AM UTC-7, Shaifali Agrawal wrote: Hello everyone I want to use xlrd, xlwt, xlutils with sagemath. I have installed them in my system's Python but sage environment is not recognizing them. Any idea how can I make them work inside sage?? I am using Ubuntu 12(quantal) with 32 bits and Sage Version 5.8 with Python 2.7.5 Got same problem with Tkinter too but solved it using sudo apt-get install tk8.5-dev got solution form http://www.sagemath.org/doc/faq/faq-usage.html#how-to-get-sage-s-python-to-recognize-my-system-s-tcl-tk-install But what for other libraries? I tried to install them manually inside /usr/lib/sagemath/local/lib/python2.7/site-packages/ folder by putting tar files then extract them and then sudo python setup.py install but still not working -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Re: xlrd, xlwt, xlutils with sage
Hey John Thanks alot!! -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Passing graphics objects
I want to create a plot by traversing a tree where some leaves of the data structure add line segments. I am trying to pass one graphics object to a function that adds a line segment to the graphics object. I assumed the graphics object is passed by reference so that changes inside the function would affect the original graphics object. However, that is not the case. How can one build up a graphics object via function calls? -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
[sage-support] Re: Passing graphics objects
Hi! Can you give a more explicit example of what you'd like to have happen? I want to create a plot by traversing a tree where some leaves of the data structure add line segments. I am trying to pass one graphics object to a function that adds a line segment to the graphics object. I assumed the graphics object is passed by reference so that changes inside the function would affect the original graphics object. However, that is not the case. How can one build up a graphics object via function calls? I'm wondering, since you just want to add, whether you could just use the + operator for this? But I may be misunderstanding this. - kcrisman -- You received this message because you are subscribed to the Google Groups sage-support group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
