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2017-12-08 05:58:01 +0200 marked best answer numerical approximations of complex_embedding

How can I get a numerical approximation of an expression like 3^(1/2)/2 which is not 0.866025403784439?

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2015-03-27 04:12:33 +0200 marked best answer cannot run: from sage.rings.number_field.splitting_field import SplittingData

When I type this line

from sage.rings.number_field.splitting_field import SplittingData

in Sage, I get the following error message:

Traceback (click to the left of this block for traceback)
...
ImportError: No module named splitting_field

I see in the online documentation that splitting fields of polynomials over number fields is very recent in Sage:

2014-01-02 Jeroen Demeyer
2015-03-27 04:12:33 +0200 marked best answer how to plot poset and subposet in a graph?

hot to put poset and subposet and order_filter and order_ideal in one graph,but different color?

PP = Posets(6)[18];show(PP,vertex_size=100,vertex_colors='yellow');

Q = PP.subposet([2,4]);Q;show(Q,vertex_size=100,vertex_colors='green')

PP.order_filter([3,2]);PP.order_ideal([4,3])

2015-03-27 04:12:32 +0200 marked best answer why sagenb.mc.edu cannot register?

sage.lacim.uqam.ca cannot register too ,why?

and sage.lacim.uqam.ca not in wiki.sagemath.org servers lists,why?

2015-03-27 04:12:28 +0200 marked best answer is notebook(interface='', secure=False) a loophole?

I try command:notebook(),it is some information about SAGENB servers......

I have no more secrity knowledge about computer,It maybe change admin passwords?

2015-03-27 04:12:25 +0200 marked best answer question about hilbert_class_polynomial

I run sagecell hilbert_class_polynomial sqrt(-5),but different with below:

http://echidna.maths.usyd.edu.au/kohe...

http://sagenb.skku.edu/home/pub/155/

2015-03-27 04:10:25 +0200 marked best answer AttributeError: 'NumberFieldFractionalIdeal' object has no attribute 'ray_class_number'

ray_class_number canot run.....

I tried an example from doc/reference:

K.<z> = QuadraticField(-23);
p = K.primes_above(3)[0];
p.ray_class_number()

x = polygen(K)
L.<w> = K.extension(x^3 - z)
I = L.ideal(5)
I.ray_class_number()
2015-03-27 04:10:01 +0200 marked best answer when I unloading a *.sws,how cannot find it out ?

I download SM_sphere_S2.sws,and uploading it (project/new/to Upload files from your computer),but where is it? no save button..... link text

2015-03-27 04:09:58 +0200 marked best answer what matrix.plot meanings?

when I run bolow,a graph appears,how to understand it?

matrix([[3,-1,1],[2,0,1],[1,-1,2]]).plot()

2015-03-27 04:09:58 +0200 marked best answer some links cannot back Sage Reference Manual

1 https://sage.epsevg.upc.edu:8000/doc/...

when link below,no button to back to Sage Reference Manual

REFERENCES:

[WpJacobianVariety] http://en.wikipedia.org/wiki/Jacobian...

2

https://sage.epsevg.upc.edu:8000/doc/...

when link below,no button to back to Sage Reference Manual,it link to http://trac.sagemath.org/13100,but blank page...

there are more links like above troubles at other places in Sage Reference Manual,I meet several times

2015-03-27 04:09:57 +0200 marked best answer where is all others published in cloud sage?

where is all others published in cloud sage?

I try cloud.sage can plot and published myself, it very well

but where others published?

the cloud projects use like labyrinth, it is too complex.......

2015-03-27 04:09:57 +0200 marked best answer how to transfer *.svg to *.gif or jepg?

how to transfer *.svg to *.gif or jepg?

2015-03-27 04:09:57 +0200 marked best answer how to define var vector?
sage: a,b,c=var("a,b,c")
sage: v = vector(QQ, ["a", "b", "c"]);v
...
TypeError: unable to convert a to a rational

cannot run

2015-03-27 04:09:56 +0200 marked best answer how to use the function ord()?

ord? there no example.

and other function like lambda?, no in index of Sage Reference Manual

2015-03-27 04:09:56 +0200 marked best answer why lim((x^2-x+1)^(1/2)+x,x=-oo,dir='below') is red error

x=-oo, negative infinity,the answei is appear,but red error,1/2 is right?

lim((x^2-x+1)^(1/2)+x,x=-oo,dir='below')

Error in lines 0-2
Traceback (most recent call last):
  File "/projects/9e8c4ed8-0b57-4535-b8f1-a0d0ef1b015b/.sagemathcloud/sage_server.py", line 841, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "<string>", line 1
    )
    ^
SyntaxError: invalid syntax
2015-03-27 04:09:56 +0200 marked best answer what meanings about global_height of AffineSpace'point

P.<x,y>=AffineSpace(QQ,2) Q=P(41,1/12) Q.global_height()

2015-03-27 04:09:19 +0200 marked best answer can sagecloud open many windows like sagenb?

sagenb has many windiws when need,how to do in sagecloud?