[sage-support] Re: simplify more quickly?

[Eric Gourgoulhon]

I've edited my answer at 
https://ask.sagemath.org/question/45959/grad-at-glacial-speed/ 
to indicate how to change the simplification algorithm.

Best wishes,

Eric.

-- 
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 https://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.

[sage-support] simplify more quickly?

[Andreas Schuldei]

i had sage perform grad() on a scalar field and the calculation was really
slow. grad() consists of several steps and apparently the derivative() is
not the issue, but rather the simplification of the resulting terms
thereafter. The process is described here:
http://doc.sagemath.org/html/en/reference/manifolds/sage/manifolds/utilities.html#sage.manifolds.utilities.simplify_chain_real

How can i perhaps skip that step and use a faster alternative? My scalar
field is a sum of some broken rational functions with a few sqrt() and
squares in it. No trigonometric stuff. I guess that might make it possible
to skip some steps in the simplification process. It is also possible to
calculate all the grad()s on the individual broken rational functions
seperatly and add them up afterwards. I don't think the terms will become
simpler as a whole compared to individually.

I would perfer if i could just plug in an other simplification algorithm
for large terms, perhaps tweakable. Is that possible? what other options do
i have?

-- 
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 https://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.

[sage-support] Can Sage be used to find a particular matrix?

[Anonymous]

Can the following problem be solved by Sage:

Prove that there is a matrix with 117 elements containing the digits such 
that one can read the squares of the numbers 1, 2, ..., 100.

Here read means that you fix the starting position and direction (8 
possibilities) and then go in that direction, concatenating the numbers. 
For example, if you can find for example the digits 1,0,0,0,0,4 
consecutively, you have found the integer 14, which contains the square 
numbers of 1, 2, 10, 100 and 20, since you can read off 1, 4, 100, 1, 
and 400 (reversed) from that sequence.

But there are so many numbers to be found (100 square numbers, to be 
precise, or 81 if you remove those that are contained in another square 
number with total 312 digits) and so few integers in a matrix that you have 
to put all those square numbers so densely that finding such a matrix is 
difficult, at least for me.

I found that if there is such a matrix mxn, we may assume without loss of 
generalty that m<=n. Therefore, the matrix must be of the type 1x117, 3x39 
or 9x13. But what kind of algorithm will find the matrix?

I have managed to do the program that checks if numbers to be added can be 
put on the board. But how can I implemented the searching algorithm?


Source, 
https://stackoverflow.com/questions/44983929/proving-that-a-particular-matrix-exists?noredirect=1=1

-- 
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 https://groups.google.com/group/sage-support.
For more options, visit https://groups.google.com/d/optout.

Re: [sage-support] Re: Sage options not recognized.

[Jose Garcia]

Hey thanks,

I took your advice, and everything is working fine now. Didn't have to use
sudo for the rest of the process. Clearly i'm new to linux and didn't know
that you could change file ownership like that. I was also able to get my
new package installed.

-Jose

On Sun, Mar 31, 2019 at 5:13 PM Dima Pasechnik  wrote:

>
>
> On Sun, 31 Mar 2019 at 21:45, Jose Garcia  wrote:
>
>> Do you think I should have installed sage somewhere other than in /opt ?
>>
>
> you can change the owner of your installation to be the “normal” user, not
> root
> using “chown”,
> no need to reinstall it.
>
>
>
>> Would it have been best to install it in my home directory?
>>
>> Any advice is appreciated.
>>
>> On Sun, Mar 31, 2019 at 4:37 PM Dima Pasechnik  wrote:
>>
>>>
>>>
>>> On Sun, 31 Mar 2019 at 21:05, Jose Garcia 
>>> wrote:
>>>
 Great news guys, turns out I just forgot to purge the SageMath
 Installation from when i used apt. So now my sage installation recognizes
 the "--package" option as well as the "-i" option for installing sagemath
 packages.

 However now I have this issue related to what appears to be writing
 right? What do you all think i should do?

 sudo sage -i conjecturing

>>>
>>> sudo? why? Sage goes out of its way to prevent one from doing
>>> installations under root,
>>> and for a good reason.
>>>
>>> make build/make/Makefile --stop
 make[1]: Entering directory '/opt/SageMath'
 rm -f config.log
 mkdir -p logs/pkgs
 ln -s logs/pkgs/config.log config.log
 running CONFIG_SHELL=/bin/bash /bin/bash ./configure --no-create
 --no-recursion
 checking for a BSD-compatible install... /usr/bin/install -c
 checking whether build environment is sane... yes
 checking for a thread-safe mkdir -p... /bin/mkdir -p
 checking for gawk... no
 checking for mawk... mawk
 checking whether make sets $(MAKE)... yes
 checking whether make supports nested variables... yes
 checking whether to enable maintainer-specific portions of Makefiles...
 yes
 checking for root user... yes
 configure: error: You cannot build Sage as root, switch to an
 unpriviledged user
 If you would like to try to build Sage anyway (to help porting),
 export the variable 'SAGE_PORT' to something non-empty.
 Makefile:39: recipe for target 'build/make/Makefile' failed
 make[1]: *** [build/make/Makefile] Error 1
 make[1]: Leaving directory '/opt/SageMath'
 Makefile:31: recipe for target 'all-toolchain' failed
 make: *** [all-toolchain] Error 2


 On Sun, Mar 31, 2019 at 10:05 AM Antonio Rojas 
 wrote:

> You are still running sage from the debian repo. You need to run
> ./sage from the dir where you installed the sage binary (or add such dir 
> to
> your PATH)
>
> El domingo, 31 de marzo de 2019, 15:29:04 (UTC+2), Jose Garcia
> escribió:
>>
>> Thank you for the response. I tried installing Sage from Binary and
>> it was successful.
>>
>> However, i still get error messages when trying to run the commands
>> to install this optional package i keep talking about.
>>
>> sage --package fix-checksum conjecturing
>> sage-run received unknown option: --package
>> usage: sage [options]
>> Try 'sage -h' for more information.
>>
>>>
>>> --
> 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 https://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 https://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 https://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