[sage-support] How to do it in cython?
Hi, I have a small (nonsense) example of a program I would like to be able to convert to cython. But I don't know how to convert: R.A,B,C=QQ[], .factor(), .unit() and .factor(proof=False,limit=10^5). I could not find anything in the documentation about for instance handling elements of R.A,B,C=QQ[], thus sage.rings.polynomial.multi_polynomial_libsingular.MPolynomial_libsingular. R.A,B,C=QQ[] def test(trio,expr=(A,B,C)): (a,b,c)=sorted(map(lambda x: abs(x(trio)),expr)) basis=prod(expr).factor() te_ontbinden=[abs(w[0](trio)) for w in basis]+[QQ(basis.unit())] radl=abs(prod(uniq([p for g in te_ontbinden for p,_ in ZZ(g).factor(proof=False,limit=10^5)]))) return radl test((1,8,9),(A^2,C^2-A^2,C^2)) 30 Any help is appreciated! Roland -- 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
Re: [sage-support] How to do it in cython?
On Jun 11, 2010, at 11:23 PM, Rolandb wrote: Hi, I have a small (nonsense) example of a program I would like to be able to convert to cython. But I don't know how to convert: R.A,B,C=QQ[], .factor(), .unit() and .factor(proof=False,limit=10^5). I could not find anything in the documentation about for instance handling elements of R.A,B,C=QQ[], thus sage .rings .polynomial.multi_polynomial_libsingular.MPolynomial_libsingular. R.A,B,C=QQ[] def test(trio,expr=(A,B,C)): (a,b,c)=sorted(map(lambda x: abs(x(trio)),expr)) basis=prod(expr).factor() te_ontbinden=[abs(w[0](trio)) for w in basis]+[QQ(basis.unit())] radl=abs(prod(uniq([p for g in te_ontbinden for p,_ in ZZ(g).factor(proof=False,limit=10^5)]))) return radl test((1,8,9),(A^2,C^2-A^2,C^2)) 30 Any help is appreciated! Roland Sage is preparsed. To see what comes out, do sage: preparse(3.factor()) 'Integer(3).factor()' sage: print preparse( R.A,B,C=QQ[] def test(trio,expr=(A,B,C)): (a,b,c)=sorted(map(lambda x: abs(x(trio)),expr)) basis=prod(expr).factor() te_ontbinden=[abs(w[0](trio)) for w in basis]+[QQ(basis.unit())] radl=abs(prod(uniq([p for g in te_ontbinden for p,_ in ZZ(g).factor(proof=False,limit=10^5)]))) return radl ) R = QQ['A, B, C']; (A, B, C,) = R._first_ngens(3) def test(trio,expr=(A,B,C)): (a,b,c)=sorted(map(lambda x: abs(x(trio)),expr)) basis=prod(expr).factor() te_ontbinden=[abs(w[Integer(0)](trio)) for w in basis]+ [QQ(basis.unit())] radl=abs(prod(uniq([p for g in te_ontbinden for p,_ in ZZ(g).factor(proof=False,limit=Integer(10)**Integer(5))]))) return radl - Robert -- 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
Re: [sage-support] Re: XPPAUT and Sage
Hi On Fri, Jun 11, 2010 at 10:30:04AM -0700, Rob wrote: I guess an XPPAUT wrapper and having xppaut included in sage is first prize. As a long-time user of XPP and python I disagree strongly. I don't think wrapping that software would be a smart way to proceed for Sage. OK. Your experience trumps my guess. Regarding another poster's comment about XPP: Of all the things to criticise, I think the complaint that XPP looks and acts old because of its X11 Tk/tcl style interface is a bit bizarre! I don't have any trouble working with it. Many, many students and faculty still pick it up and use it, especially if they don't want to get too bogged down in programming. But I agree that if you want to invest your time wisely for the future, and you are willing to learn a proper programming language, a python-based approach is the way to go. Same poster :) I respectfully disagree on the sentiment 1. Interface matters. A lot. Nothing bizarre about that. 2. Many, many do. Many, many don't. Tit for tat. I work with students and researchers new to computing. They do not have the memory we have of when this style was advanced. 3. My advice was that XPP is worth it despite its atrocious cursor focus and cut/copy/paste behaviour, in this day and age. I guess we're making the same point there. regards, Jan -- .~. /V\ Jan Groenewald /( )\www.aims.ac.za ^^-^^ -- 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
Re: [sage-support] loading files
Hi Amelia,
How did you try to load the file?
I guess you are using the notebook.
There it is possible to load a file with
load('absolute_path').
If you are using the command line version you can also use
run absolute or relative path
or
run -i absolute or relative path
for running your script in the actual namespace.
Cheers..
On 06/12/2010 06:07 AM, ataylor wrote:
Hi.
I have a MacOS 10.5.8 and while I used sage a long time ago, I have
students who need to use sage now and so am being reintroduced.
Today we wrote a little for loop and called the file sageprogram.sage
just to get started. However, we cannot, for the life of us load the
file into sage.
(1) we did check the sage path and put the file into a folder that is
definitely on the path --- namely /Applications/sage/
(2) The error we get is
Traceback (click to the left of this block for traceback)
...
IOError: [Errno 2] No such file or directory: 'sageprogram.sage'
Which makes sense if the file is not on the path searched by sage, but
it appears to be so.
Clearly sage is not finding the program. However, we can't find
anything (looked in the tutorial and the reference manual) to help us
help sage find the file. In the tutorial where it talks about loading
and attaching files it does not say anything about paths or where to
place the files.
- Amelia
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[sage-support] Re: How to do it in cython?
On 12 Jun., 08:56, Robert Bradshaw rober...@math.washington.edu wrote: Sage is preparsed. ... ... and the preparser is not used on .pyx and .py files. So, when you write 3 in a .pyx file, it becomes a python int, but if you write 3 on the Sage command line, it is interpreted (by the preparser) as a Sage integer. However, if I am not mistaken, Cython code *is* preparsed if it is put into a .spyx (not .pyx) filed. Cheers, Simon -- 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
Re: [sage-support] Re: Building from source sage 4.4.3 under Debian lenny amd64: gcc and g++ versions do not match
On 12 June 2010 06:56, Jan Groenewald j...@aims.ac.za wrote: Hi On Fri, Jun 11, 2010 at 03:30:54PM -0700, orca wrote: Furthermore, if I type $ sudo update-alternatives --config java I get a list of java systems I can choose from. I think you might get a similar list for gcc and g++? I think the correct way is CC and CXX variables. That does not have a hope in hell's chance of working. Too man parts in Sage have 'gcc' or 'g++' encoded in them and will ignore CC and CXX. I find it very frustrating this myself. https://bugs.launchpad.net/ubuntu/+source/gcc-4.2/+bug/145486 Possible in alternatives, but not advised: http://www.doitian.com/2009/06/switch-gcc-41-and-43-in-ubuntu/ regards, Jan Dave -- 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: loading files
Tobias,
We are using the notebook, but knowing how to do it command line is
also helpful.
So it is true that we did not know to use . However, I'm still
doing something wrong. I entered
load /Users/ataylor/research/Students/EliseAndrew/sageprogram.sage
and I know this is closer because my error changed. The error now
says
ValueError: argument
(='/Users/ataylor/research/Students/EliseAndrew/sageprogram.sage\
') to load or attach must have extension py, sage, or pyx
But our program does have the extension sage. So I'm not sure why it
is telling me this.
- Amelia
On Jun 12, 1:28 am, Tobias Katz tobi...@web.de wrote:
Hi Amelia,
How did you try to load the file?
I guess you are using the notebook.
There it is possible to load a file with
load('absolute_path').
If you are using the command line version you can also use
run absolute or relative path
or
run -i absolute or relative path
for running your script in the actual namespace.
Cheers..
On 06/12/2010 06:07 AM, ataylor wrote:
Hi.
I have a MacOS 10.5.8 and while I used sage a long time ago, I have
students who need to use sage now and so am being reintroduced.
Today we wrote a little for loop and called the file sageprogram.sage
just to get started. However, we cannot, for the life of us load the
file into sage.
(1) we did check the sage path and put the file into a folder that is
definitely on the path --- namely /Applications/sage/
(2) The error we get is
Traceback (click to the left of this block for traceback)
...
IOError: [Errno 2] No such file or directory: 'sageprogram.sage'
Which makes sense if the file is not on the path searched by sage, but
it appears to be so.
Clearly sage is not finding the program. However, we can't find
anything (looked in the tutorial and the reference manual) to help us
help sage find the file. In the tutorial where it talks about loading
and attaching files it does not say anything about paths or where to
place the files.
- Amelia
--
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To unsubscribe from this group, send email to
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URL: http://www.sagemath.org
Re: [sage-support] Re: loading files
Hi,
x has been only a placeholder.
In your case you probably would have to enter
load('/Users/ataylor/research/Students/EliseAndrew/sageprogram.sage')
Good luck with it!
Tobi
On 06/12/2010 04:06 PM, ataylor wrote:
Tobias,
We are using the notebook, but knowing how to do it command line is
also helpful.
So it is true that we did not know to use . However, I'm still
doing something wrong. I entered
load /Users/ataylor/research/Students/EliseAndrew/sageprogram.sage
and I know this is closer because my error changed. The error now
says
ValueError: argument
(='/Users/ataylor/research/Students/EliseAndrew/sageprogram.sage\
') to load or attach must have extension py, sage, or pyx
But our program does have the extension sage. So I'm not sure why it
is telling me this.
- Amelia
On Jun 12, 1:28 am, Tobias Katz tobi...@web.de wrote:
Hi Amelia,
How did you try to load the file?
I guess you are using the notebook.
There it is possible to load a file with
load('absolute_path').
If you are using the command line version you can also use
run absolute or relative path
or
run -i absolute or relative path
for running your script in the actual namespace.
Cheers..
On 06/12/2010 06:07 AM, ataylor wrote:
Hi.
I have a MacOS 10.5.8 and while I used sage a long time ago, I have
students who need to use sage now and so am being reintroduced.
Today we wrote a little for loop and called the file sageprogram.sage
just to get started. However, we cannot, for the life of us load the
file into sage.
(1) we did check the sage path and put the file into a folder that is
definitely on the path --- namely /Applications/sage/
(2) The error we get is
Traceback (click to the left of this block for traceback)
...
IOError: [Errno 2] No such file or directory: 'sageprogram.sage'
Which makes sense if the file is not on the path searched by sage, but
it appears to be so.
Clearly sage is not finding the program. However, we can't find
anything (looked in the tutorial and the reference manual) to help us
help sage find the file. In the tutorial where it talks about loading
and attaching files it does not say anything about paths or where to
place the files.
- Amelia
--
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To unsubscribe from this group, send email to
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URL: http://www.sagemath.org
[sage-support] Re: Building from source sage 4.4.3 under Debian lenny amd64: gcc and g++ versions do not match
Hi, I do not understand the suggestion in this thread, but Sage compiles fine on Debian Lenny The compiled Sage is at http://user.mendelu.cz/marik/temp/sage-4.4.3-x86_64-Linux.tar.gz My configuration: ma...@um-bc107:/opt$ uname -a Linux um-bc107 2.6.26-2-amd64 #1 SMP Wed May 12 18:03:14 UTC 2010 x86_64 GNU/Linux Hope this helps Robert -- 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: loading files
Got It. Success. Thanks! I'm surprised at my syntax troubles with
this, but it all makes sense now.
Appreciated,
Amelia
On Jun 12, 8:21 am, Tobias Katz tobi...@web.de wrote:
Hi,
x has been only a placeholder.
In your case you probably would have to enter
load('/Users/ataylor/research/Students/EliseAndrew/sageprogram.sage')
Good luck with it!
Tobi
On 06/12/2010 04:06 PM, ataylor wrote:
Tobias,
We are using the notebook, but knowing how to do it command line is
also helpful.
So it is true that we did not know to use . However, I'm still
doing something wrong. I entered
load /Users/ataylor/research/Students/EliseAndrew/sageprogram.sage
and I know this is closer because my error changed. The error now
says
ValueError: argument
(='/Users/ataylor/research/Students/EliseAndrew/sageprogram.sage\
') to load or attach must have extension py, sage, or pyx
But our program does have the extension sage. So I'm not sure why it
is telling me this.
- Amelia
On Jun 12, 1:28 am, Tobias Katz tobi...@web.de wrote:
Hi Amelia,
How did you try to load the file?
I guess you are using the notebook.
There it is possible to load a file with
load('absolute_path').
If you are using the command line version you can also use
run absolute or relative path
or
run -i absolute or relative path
for running your script in the actual namespace.
Cheers..
On 06/12/2010 06:07 AM, ataylor wrote:
Hi.
I have a MacOS 10.5.8 and while I used sage a long time ago, I have
students who need to use sage now and so am being reintroduced.
Today we wrote a little for loop and called the file sageprogram.sage
just to get started. However, we cannot, for the life of us load the
file into sage.
(1) we did check the sage path and put the file into a folder that is
definitely on the path --- namely /Applications/sage/
(2) The error we get is
Traceback (click to the left of this block for traceback)
...
IOError: [Errno 2] No such file or directory: 'sageprogram.sage'
Which makes sense if the file is not on the path searched by sage, but
it appears to be so.
Clearly sage is not finding the program. However, we can't find
anything (looked in the tutorial and the reference manual) to help us
help sage find the file. In the tutorial where it talks about loading
and attaching files it does not say anything about paths or where to
place the files.
- Amelia
--
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
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URL: http://www.sagemath.org
[sage-support] Re: Building from source sage 4.4.3 under Debian lenny amd64: gcc and g++ versions do not match
Sorry Marik and Bradshaw, but I use Debian for some five years now and I just have a plain vanilla Debian lenny (current stable) and the NORMAL gcc, g++ and gfortran, as I have suggested in my first post in this thread, and as I state categorically now, sure do not all match: the stock lenny gcc is 4.3.2, g++ is 4.2.4, and gfortran is 4.3.2. I have now installed both versions 4.2 and 4.3 from the official Debian lenny repositories for all three mentioned compilers. I have now tried the following make command in order to drive the building with the matched 4.2 versions of all these compilers: make CC=gcc-4.2 FC=gfortran-4.2 The following error is now issued: Found gcc 4 or later make[2]: Entering directory `/home/orca/sage/sage-4.4.3/spkg/build/ flint-1.5.0.p4/src' gcc-4.2 -I/home/orca/sage/sage-4.4.3/local/include/ -I/home/orca/sage/ sage-4.4.3/local/include -fPIC -funroll-loops -O2 -DNDEBUG -o zn_mod.o -c zn_poly/src/zn_mod.c In file included from zn_poly/src/zn_poly_internal.h:50, from zn_poly/src/zn_mod.c:23: zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_negate’: zn_poly/src/../../mpn_extras.h:75: error: ‘for’ loop initial declaration used outside C99 mode zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_copy’: zn_poly/src/../../mpn_extras.h:96: error: ‘for’ loop initial declaration used outside C99 mode zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_copy_forward’: zn_poly/src/../../mpn_extras.h:104: error: ‘for’ loop initial declaration used outside C99 mode zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_clear’: zn_poly/src/../../mpn_extras.h:118: error: ‘for’ loop initial declaration used outside C99 mode zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_set’: zn_poly/src/../../mpn_extras.h:129: error: ‘for’ loop initial declaration used outside C99 mode zn_poly/src/../../mpn_extras.h: In function ‘F_mpn_printx’: zn_poly/src/../../mpn_extras.h:145: error: ‘for’ loop initial declaration used outside C99 mode make[2]: *** [zn_mod.o] Error 1 make[2]: Leaving directory `/home/orca/sage/sage-4.4.3/spkg/build/ flint-1.5.0.p4/src' Error building flint shared library. real0m0.098s user0m0.068s sys 0m0.024s sage: An error occurred while installing flint-1.5.0.p4 Please email sage-devel http://groups.google.com/group/sage-devel explaining the problem and send the relevant part of of /home/orca/sage/sage-4.4.3/install.log. Describe your computer, operating system, etc. If you want to try to fix the problem yourself, *don't* just cd to /home/orca/sage/sage-4.4.3/spkg/build/flint-1.5.0.p4 and type 'make check' or whatever is appropriate. Instead, the following commands setup all environment variables correctly and load a subshell for you to debug the error: (cd '/home/orca/sage/sage-4.4.3/spkg/build/flint-1.5.0.p4' '/home/ orca/sage/sage-4.4.3/sage' -sh) When you are done debugging, you can type exit to leave the subshell. make[1]: *** [installed/flint-1.5.0.p4] Error 1 make[1]: Leaving directory `/home/orca/sage/sage-4.4.3/spkg' real26m35.080s user21m55.518s sys 3m11.324s Error building Sage. ./sage -docbuild all html 21 | tee -a dochtml.log python: can't open file '/home/orca/sage/sage-4.4.3/devel/sage/doc/ common/builder.py': [Errno 2] No such file or directory I wil take the liberty to forward this error to the sage-dev list as well... Any other concrete directions are warmly appreciated! On Jun 12, 1:06 pm, Robert Bradshaw rober...@math.washington.edu wrote: On Jun 12, 2010, at 7:51 AM, ma...@mendelu.cz wrote: Hi, I do not understand the suggestion in this thread, but Sage compiles fine on Debian Lenny Yes, it does. This thread was started due to a mismatch in the gcc and g++ versions. If both versions are the same (which is the norm), it should compile from source just fine. - Robert -- 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: Building from source sage 4.4.3 under Debian lenny amd64: gcc and g++ versions do not match
On 12 čvn, 23:10, orca mocal...@gmail.com wrote: Sorry Marik and Bradshaw, but I use Debian for some five years now and I just have a plain vanilla Debian lenny (current stable) and the I have the same version of gcc and g++, see also http://packages.debian.org/lenny/g++ and http://packages.debian.org/lenny/g++ -- both versions are 4.3.2 You may have broken installation, installation which is not up to date or frozen package g++ ... Do you have 64 bit system? Does my package work on your computer? Another my suggestion is to install new Debian Lenny in virtual machine, compile in this virtual machine and finally move to physical machine. Does this help? Robert M. -- 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] strange behavior in matrix substitution
Please tell me if this is a bug, or, I'm missing something obvious... sage: a = 3 # Assign a value to a variable a sage: b = a # Create a copy of a sage: b = 2 # Change the value of b sage: b 2 sage: a # The value of a remains unchanged, as expected. 3 So far, it looks good to me. But, when I do a similar thing with matrices, it doesn't look to be the same. sage: v = matrix(ZZ, 3, range(9)) sage: u = v sage: u[2] = [0,0,0] sage: u [0 1 2] [3 4 5] [0 0 0] sage: v [0 1 2] [3 4 5] [0 0 0] Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? -- 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
Re: [sage-support] strange behavior in matrix substitution
On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: Please tell me if this is a bug, or, I'm missing something obvious... sage: a = 3 # Assign a value to a variable a sage: b = a # Create a copy of a sage: b = 2 # Change the value of b sage: b 2 sage: a # The value of a remains unchanged, as expected. 3 So far, it looks good to me. But, when I do a similar thing with matrices, it doesn't look to be the same. sage: v = matrix(ZZ, 3, range(9)) sage: u = v sage: u[2] = [0,0,0] sage: u [0 1 2] [3 4 5] [0 0 0] sage: v [0 1 2] [3 4 5] [0 0 0] Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? You might think the behavior should be the same, but that's not the case. Objects with structure (matrices, for example) are copied by reference, while things like integers, which have little or no structure (from the user's perspective at any rate) are copied by value. What that means is that, for matrices, u=v means that the names u,v now refer to the same Sage object, so when you modify one, you are modifying the other (since you are really modifying the underlying object). For, e.g., integers, u=v means that the names u,v both refer to their own copies of the value in question. This is, BTW, the way Python works, and Python is the language with which (most of) Sage is implemented. In case you didn't already know that :-} HTH. Justin -- Justin C. Walker, Curmudgeon at Large Director Institute for the Enhancement of the Director's income --- -- They said it couldn't be done, but sometimes, it doesn't work out that way. - Casey Stengel -- -- 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
Re: [sage-support] strange behavior in matrix substitution
Hello, On Sat, Jun 12, 2010 at 5:27 PM, Byungchul Cha cha3...@gmail.com wrote: Please tell me if this is a bug, or, I'm missing something obvious... sage: a = 3 # Assign a value to a variable a sage: b = a # Create a copy of a This does not create a copy of a. When you do a = 3, this creates new object for the integer 3 and then makes a point to that object. When you do b = a, it makes b point to the object that you originally created. When you do b = 2, it makes a new object for the integer 2 and makes b point to that. Notice that you are never changing (mutating) any of the objects. So far, it looks good to me. But, when I do a similar thing with matrices, it doesn't look to be the same. ... Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? Here, the line sage: u[2] = [0,0,0] change the object that u in referencing. Since u and v point to that same object (as above), you see the changes when you look at v. You can use copy() to actually make a copy of v: sage: sage: v = matrix(ZZ, 3, range(9)) sage: v = matrix(ZZ, 3, range(9)) sage: u = copy(v) sage: u[2] = [0,0,0] sage: u [0 1 2] [3 4 5] [0 0 0] sage: v [0 1 2] [3 4 5] [6 7 8] --Mike -- 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
Re: [sage-support] strange behavior in matrix substitution
On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: Please tell me if this is a bug, or, I'm missing something obvious... sage: a = 3 # Assign a value to a variable a sage: b = a # Create a copy of a sage: b = 2 # Change the value of b sage: b 2 sage: a # The value of a remains unchanged, as expected. 3 So far, it looks good to me. But, when I do a similar thing with matrices, it doesn't look to be the same. sage: v = matrix(ZZ, 3, range(9)) sage: u = v sage: u[2] = [0,0,0] sage: u [0 1 2] [3 4 5] [0 0 0] sage: v [0 1 2] [3 4 5] [0 0 0] Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? You might think the behavior should be the same, but that's not the case. Objects with structure (matrices, for example) are copied by reference, while things like integers, which have little or no structure (from the user's perspective at any rate) are copied by value. What that means is that, for matrices, u=v means that the names u,v now refer to the same Sage object, so when you modify one, you are modifying the other (since you are really modifying the underlying object). For, e.g., integers, u=v means that the names u,v both refer to their own copies of the value in question. Are you sure??? I think you statement that u is a new copy is wrong. I bet u is v would still return true above. I can't check this now, since am on iPhone This is, BTW, the way Pythttp://www.cnn.com/2010/HEALTH/05/29/energy.boosters/hon works, and Python is the language with which (most of) Sage is implemented. In case you didn't already know that :-} HTH. Justin -- Justin C. Walker, Curmudgeon at Large Director Institute for the Enhancement of the Director's income --- -- They said it couldn't be done, but sometimes, it doesn't work out that way. - Casey Stengel -- -- 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 -- William Stein Professor of Mathematics University of Washington http://wstein.org -- 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
Re: [sage-support] strange behavior in matrix substitution
On Jun 12, 2010, at 19:07 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: [snip] Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? [snip] For, e.g., integers, u=v means that the names u,v both refer to their own copies of the value in question. Are you sure??? I think you statement that u is a new copy is wrong. I bet u is v would still return true above. Picky picky picky. I was hoping to avoid a trip into the twisty maze of passages in language definition (all of which are subtly different :-}). But you are correct. u is v does return true and the two actually refer to the same (physical) value. And, if one variable is modified, this doesn't modify the other, or the value that both previously referred to. I can't check this now, since am on iPhone I find that hard to believe. I thought you had Sage running on all things digital... Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income When LuteFisk is outlawed, Only outlaws will have LuteFisk -- 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
Re: [sage-support] strange behavior in matrix substitution
On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 19:07 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: [snip] Shouldn't the value of v remain the same? Why does the change in u (or, a row of u) affect v? [snip] For, e.g., integers, u=v means that the names u,v both refer to their own copies of the value in question. Are you sure??? I think you statement that u is a new copy is wrong. I bet u is v would still return true above. Picky picky picky. I was hoping to avoid a trip into the twisty maze of passages in language definition (all of which are subtly different :-}). But you are correct. u is v does return true and the two actually refer to the same (physical) value. And, if one variable is modified, this doesn't modify the other, or the value that both previously referred to. I can't check this now, since am on iPhone I find that hard to believe. I thought you had Sage running on all things digital... Your right that I could check it on my iPhone, but I was lazy.I'm working on building sage *on* my ipad bit haven't finished yet Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income When LuteFisk is outlawed, Only outlaws will have LuteFisk -- 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 -- William Stein Professor of Mathematics University of Washington http://wstein.org -- 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
Re: [sage-support] strange behavior in matrix substitution
On Jun 12, 2010, at 20:30 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 19:07 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: [snip] [snip] I find that hard to believe. I thought you had Sage running on all things digital... Your right that I could check it on my iPhone, but I was lazy.I'm working on building sage *on* my ipad bit haven't finished yet OK, that would be cool. Would one have to jailbreak to run it? Justin -- Justin C. Walker, Curmudgeon at Large Institute for the Absorption of Federal Funds --- Like the ski resort full of girls hunting for husbands and husbands hunting for girls, the situation is not as symmetrical as it might seem. - Alan MacKay -- -- 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 on iPhone - Re: [sage-support] strange behavior in matrix substitution
On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 20:30 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 19:07 , William Stein wrote: On Saturday, June 12, 2010, Justin C. Walker jus...@mac.com wrote: On Jun 12, 2010, at 17:27 , Byungchul Cha wrote: [snip] [snip] I find that hard to believe. I thought you had Sage running on all things digital... Your right that I could check it on my iPhone, but I was lazy. I'm working on building sage *on* my ipad bit haven't finished yet OK, that would be cool. Would one have to jailbreak to run it? Yes, unfortunately. Also there's no iPhone fortran (yet), so only parts of sage will build. I'll show you at MSRI at sage days 22... Justin -- Justin C. Walker, Curmudgeon at Large Institute for the Absorption of Federal Funds --- Like the ski resort full of girls hunting for husbands and husbands hunting for girls, the situation is not as symmetrical as it might seem. - Alan MacKay -- -- 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 -- William Stein Professor of Mathematics University of Washington http://wstein.org -- 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
