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Luiz Roberto Meier's profile - activity

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2013-11-09 20:31:07 +0100 answered a question jmol Applet failure in any distro.

Using SAGE 5.12 , jmol applet will runs only in the same window where the notebook was opened. When the pop-up for the help/tutorials is used jmol applet fails to load.

2013-11-09 12:27:52 +0100 commented answer Limit of complex functions

Thank you!

2013-11-09 12:27:34 +0100 marked best answer Limit of complex functions

I am not sure i understand you question since you gave two fixed values to x and x1. If you want to find the limit of the function some_function = (z -> z*z1) when z goes to z1, you can define a symbolic function (not to be confused with a python function) :

sage: z1 = 3 + 4*I
sage: some_function(z) = z * z1
sage: some_function
z |--> (4*I + 3)*z
sage: some_function.limit(z=z1)
24*I - 7
2013-11-08 16:03:01 +0100 asked a question Limit of complex functions


Suppose I have 2 complex numbers, z and z1 , where z = 1+2I and z1 = 3 + 4I (just an example). How can I compute the following: some_function = z * z1 and I want to know how to find the limit of some_function when z = z1.

I tried hard to find an answer. I used def to define a function, I could define the complex numbers and I can use the limit with rational / real values, but, when I use a complex number, the limit just return the entire explession.

Thank you for any idea / URL to help me.

2013-10-25 10:10:07 +0100 answered a question Running SAGE in the own network

I figure out the problem: I had to flush my iptables and then I set it again to accept connections from 192.168.x.y only at port 8080 (I can change the default port) and worked fine. Now I can 'see' my SAGE server from my tablet, laptops and desktops. No need to install it in more than 2 computers.

Also I probed the port 8080 from outside the network and it is closed/stealth (both) , so , my guess it is secure.

Thank you all !

2013-10-25 09:12:22 +0100 commented answer Running SAGE in the own network

I will try now to redo all the steps.. 1) Install of SAGE binary and test if it runs normally in localhost; 2) Reconfigure the firewall of Fedora 18; Can you please show me the line you added in your ipchains to let other from your own network access the SAGE server?

2013-10-25 09:11:07 +0100 commented answer Running SAGE in the own network

Still not working. Just can't find the local ip address with the port 8080 or 80 whatever. But all the other services (running for lan only) runs normally, I can use apache, oracle, anything. Thanks anyway.

2013-10-23 20:33:13 +0100 commented answer Running SAGE in the own network

@Luca The errors has gone , but I still unable to connect.

2013-10-23 15:29:00 +0100 commented answer Running SAGE in the own network

Still not working... maybe there is some .htaccess in somewhere in SAGE folders?

2013-10-23 13:50:48 +0100 commented answer Running SAGE in the own network

After running the command told by @ppurka I got the following errors: Executing twistd --pidfile="sage_notebook.sagenb/" -ny "sage_notebook.sagenb/twistedconf.tac" 2013-10-23 14:46:26-0200 [-] Log opened. 2013-10-23 14:46:26-0200 [-] twistd 12.3.0 (/home/lm/sage-5.11-linux-64bit-fedora_release_16_verne-x86_64-Linux/local/bin/python 2.7.5) starting up. 2013-10-23 14:46:26-0200 [-] reactor class: twisted.internet.epollreactor.EPollReactor. 2013-10-23 14:46:26-0200 [-] Traceback (most recent call last):

2013-10-23 10:44:02 +0100 commented answer Running SAGE in the own network

Yes, @Luca , I can connect to Oracle and tested FTP and Apache. Also, I changed the 8080 to 5000, 6000, 7000 ports and still not working. I can run only in the machine , using the localhost, 192.168.2.x port 8080. I ping and the ports answers but 8080

2013-10-23 01:38:07 +0100 commented answer Running SAGE in the own network

Thank you for the links but none solved my problem. I still not be able to connect from another PC or tablet to the IP of where sage server is running. I can run it via notebook() and using interface, so, in the computer where the server is I can just type (my local_ip, path + user that I created) and it works.. but if I try from any other pc/tablet I can't connect.. maybe it isn't a sage issue but my local firewall.. I got no error message from Sage, the browsers just can't find the server.

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2013-10-23 01:32:47 +0100 commented answer Running SAGE in the own network

Still not working.

2013-10-23 00:28:45 +0100 asked a question Running SAGE in the own network


I'm using Fedora 18 64bits where I installed the SAGE and it runs normally when I'm using localhost:8080 and with local ip of the machine: (as an example).

I checked the firewall (ipchains) , any computer can connect to . I'm trying to run in my tablet (and several computers in a class) the SAGE in the LAN (others programs/servers are working fine).

I did a search in google and here, I'm almost 1 week trying to solve this. I can't connect in the SAGE machine/server from other computers in the local network.

1) Can someone please explain how to set it to run locally?

2) Why not include in future releases an option to automatically turn it on to an entire network and maybe outside (public)? The security issues is up to the admin of the server.

Thank you very much for the attention.

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2013-04-19 21:09:44 +0100 commented answer Showing options after writing "." when you choose an element of a list

Thank you.

2013-04-19 20:59:33 +0100 commented answer Using "j" for Imaginary Unit?

Mr... kcrisman, You keep warning my helps. I'm just trying to help. If later the solution isn't sufficient or the correct one, it isn't my fault but the lack or organizational documentation. There is a pain to find some simple solutions when it isn't in the name of a section of some kind of manual. As you know much more than me, why don't you help to solve? Give a best answer to the above question, you will help the user and forget my ignorance.

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2013-04-19 07:32:14 +0100 marked best answer Notebook environment ( cell width)


If it is the output's withd what you aim to increase, just go to "Settings" (top-left of the notebook), then "Notebook settings", and increase the value of "Number of word-wrap columns" (e.g. I have it at 150). Then just "Save" with the button at the bottom and you are done.

2013-04-19 06:59:56 +0100 commented answer Notebook environment ( cell width)

Thank you!

2013-04-19 04:56:18 +0100 answered a question Showing options after writing "." when you choose an element of a list

Will be practical for you to use a loop with this inside:


some loop here


z = c[0]

z. <tab> will work.

2013-04-19 04:38:27 +0100 answered a question Using "j" for Imaginary Unit?

After peruse a lot of files and docs maybe I have found a simple solution:

sage: var('j,w,t')

(j, w, t)

sage: j = complex(I)

sage: exp( j * w * t )

e^( 1j * w * t )

2013-04-19 01:43:21 +0100 asked a question Notebook environment ( cell width)


I'm trying to find in manuals and sites how can I extend the cell width (I'm using the notebook environment) because while the notebook itself occupies the entire screen, normally the output cell is breaking with the \ symbol . The command show() put the entire output in a single line.. so.. How can I have the option or what should I read about to change the cell width? I'm needing that because of some matrix and group theory output tables.

Thank you in advance.

2013-04-15 07:48:13 +0100 commented answer Problem using GAP

I thank you very much for your entire time/answer. That's correct! I will try to identify how to display or produce only positive powers and if I sucess I will post it here. Thank you again!

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2013-04-14 21:55:38 +0100 asked a question Problem using GAP


I'm starting to use the GAP package/software with the follow commands to define a simple finite group:

gap> f := FreeGroup("x");

<free group="" on="" the="" generators="" [="" x="" ]&gt;<="" p="">

gap> AssignGeneratorVariables(f);

I Assigned the global variables [ x ]

gap> x^5 * x^-7;


gap> g := f/[x^5];

<fp group="" on="" the="" generators="" [x]&gt;<="" p="">

gap> AssignGeneratorVariables(g);

I Global Variable ‘x’ already defined and will be overwritten I Assigned the global variables [ x ]

gap> Size(g);


gap> List(g);

Here is the problem, I should get:

[ identity ..., x, x^2, x^3, x^4 ]

but instead, I got:

[ identity ..., x, x^-1, x^2, x^-2 ]

1) What am I doing wrong, please?

Also, the command:

gap> MultTable(g);

Error, Variable: 'MultTable' must have a value not in any function at line 8 of stdin

Can someone please help with that? I have a lot of ideas on Group / Abstract Algebra but despite I use/read the GAP manual I can't create a simple multiplication table.

Any hint/help will be appreciate.

Thank you in advance.

2013-03-27 00:09:09 +0100 commented question Table of primes

You can think about it as a group too. But, forget. I can learn it alone without your funny help.