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2017-07-21 16:45:30 -0500 commented question How to plot a complicated function in Sage Math

My bad I thought it was abs(x) instead of floor(x)

2017-07-01 17:51:28 -0500 commented question How to plot a complicated function in Sage Math

So do you want to plot a function which is 1 for x>=0 and +Infinity for x<0?

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2017-04-13 22:07:09 -0500 answered a question Launch Sage Notebook directly from linux menu

I found the solutions above way too slow. I have all my sagemath notebooks on a sagemathNB folder in Documents. In my ~/bin I created a script called sage_nb

#!/bin/bash
cd ~/Documents/sagemathNB
$SAGE ROOT/sage -n jupyter

Remember to chmod +x sage_nb Then I create a SageMath.desktop file in my desktop

[Desktop Entry]
Name=Jupyter notebook with Sage
Name[en]=Jupyter notebook with Sage
Comment=Scientific Computing using Jupyter notebook and Sage
Comment[en]=Scientific Computing using Jupyter notebook and Sage
Exec=sage_nb
Icon=$SAGE ROOT/src/ext/notebook-ipython/logo.svg
Terminal=false
Type=Application
Categories=Education;Math;Science;
StartupNotify=true
Name[en_US]=SageMath

Finally you can copy to sudo cp SageMath.desktop /usr/share/applications/

2017-04-01 07:05:37 -0500 received badge  Scholar (source)
2017-03-31 19:23:12 -0500 asked a question weird behavior of set and uniq

Hi all, I have a list of coefficients (which are variables) and I want to remove duplicates. In my original file (from May 2015) I could use set and or unique now both of them give me the same error

TypeError: <class 'sage.manifolds.coord_func_symb.CoordFunctionSymbRing_with_category.element_class'> is not hashable

Whenever I try to use the same commands with another list I don't have any error. I'm still scratching my head. here is the notebook. I don't have enough karma to publish a link

cloud.sagemath.com/projects/263f082f-dc10-4817-a88d-d87700640552/files/Ask+sage.html

2016-04-23 06:39:09 -0500 commented question Assume that n is positive integer

It is pretty weird. If you type

assume(n,'integer')
assume(n>0)

The command

assumptions()

returns

[ n is integer,n > 0,]

and

n.is_integer()

returns false. But if you assume the other way around

assume(n>0)
assume(n,'integer')

then

n.is_integer()

returns true. I guess it's a sort of bug

2016-04-23 06:39:08 -0500 commented answer Fast show()? (for cached plots for @interact)

Do you know if things are changed right now? I can't load the module Image.

2015-05-23 17:39:21 -0500 answered a question what is the command for unzipping a folder in sagemathCloud

Open a terminal and use linux commands:

http://askubuntu.com/questions/86849/...

2015-05-23 17:37:51 -0500 answered a question Matrix/Tensor derivative for Stress Tensor

Have you tried SageManifolds? sagemanifolds.obspm.fr

I do tensor calculus with it and I think it's good. Then as Juanlu001 already told you try to use diff and post your code.

2015-05-17 07:31:48 -0500 commented answer Solving a symbolic inequality

In the first case your solution is fine:

var('b,c,d')

assume(c<0)

solve(18bcd - 4b^3d + b^2c^2 - 4c^3 - 27d^2==0,d)

But I would like to know if there is a way to have a solution without "trying to understand" where the sign change. I think is the main point to use a math software. Furthermore it'll be pretty annoying if there is anything like that implemented already as with Mathematica is a one line command

Reduce[{b^2 c^2-4 c^3-4 b^3 d+18 b c d-27 d^2>0,c<0},d]