nerak99's profile - activity

composite function simplify expressions and strings I am using code like x=simplify(f(g(g(h(f(g(f(g(f(k)))))))))) t

composite function simplify expressions and strings I am using code like x=simplify(f(g(g(h(f(g(f(g(f(k)))))))))) t

The title says it all really. I think I can use ‘expand’ but can’t work out the syntax. Eg, given f(x) = a polynomial and g(x) = some other bit of algebra can I expand fg(x)

Thank you for your prompt response. I will have a go later on today.

Can I expand a composite function symbolically in sage The title says it all really. I think I can use ‘expand’ but can’

I can't see the sage command line that you speak of. I am using cloud.sagemath though. I have managed to get jmol import of three.js objects to work. I think that in the screen rendering, three.js is involved.

How do I access the context menu in the jmol applet?

I want to export 3D plots from Sage in some 3D format or other (NOt just a single png frame)

This script produces a jMol file for me. (I am on cloud.sagemath)

> from sage.interfaces.jmoldata import JmolData 3 sage: JData = JmolData() 4
> u,v = var('u v') 5 f_x = u 6 f_y =
> cos(1*v) 7 f_z = sin(3*v) 8
> img=parametric_plot3d([f_x, f_y, f_z],
> (u, 0, 0.6), (v, 0, 6*pi),
> color='blue', mesh=1, frame=False) 9
> img.save('myfile.png') 10
> img.export_jmol('thisjmol') 11 img 12

The file produced is about 20K or so but if I try to open it via JMol standalone viewer I just get black.

Mind you if I try the example jmols I also get black.

My end point is to get the 3D view into a 3D package such as Blender but to start with I need to get my 3D image out of sage.

Any idea of where I am going wrong?

Duh, I haver to restrict the range on the first function. Sorry

I want to plot a function and its inverse. I issue

F=plot ((2*(x^3-2)),-4,0)
G=plot(sign(0.5*x+2.0)*abs(0.5*x+2.0)^(1/3),-4,0)
F+G

Now 2(x^3-2) is the inverse of (0.5x+2)^(1/3) (I even checked with a well known alternative to sage).

The plots come out with the scale of 2(x^3-2) all wrong. They should (obviously) be reflections in y=x.

Any help much appreciated

That command does not appear to call plot anyway.

I plotted the vector field like this

p3= plot_vector_field( ((x+4)/sqrt((x+4)^2+y^2)+(x-6)/sqrt((x-6)^2+y^2), y/sqrt((x+4)^2+y^2)), (x, -10, 10), (y, -10, 10))

I would like to do a contour plot where contour joind points at the same value. How do I do that?

There is a place in the Sage appliance wiki that is out of date. I will fix that, meanwhile I put a document at https://dl.dropbox.com/u/79070435/CAS... which describes the sage appliance install with the errors fixed. I would appreciate any comments about this that anyone cares to make.

Absolutely I didn't, sorry about that. I am using sage as a way of allowing children in class to do some Python coding in a situation where the service provider won't allow installation of any programming software.

How can I write a script that will get user input when the script runs. I am talking about the sage notebook() here rather than the cli sage.

Essentially, the wiki is out of date because the launch is carried out in .xinitrc If you want a multiuser sage then comment out the xinit and shutdown -h now lines in .bash_profile and insert a sage launch line in .bash_profile. The program will now behave as expected.

FYI it appears to launch from .xinitrc. I expect I will be able to fix the thing to work as the wiki describes

Any info about how the launch now works would help me. I just need to intercept where sage is launched and chrome is also launched. Clearly not .bash_profile except via this alias thing?

The sage appliance wiki suggests editing the sage user .bash_profile as follows

"and replace the line

./sage -notebook interface=\'\' port=8000 open_viewer=False require_login=False

with

./sage -notebook interface=\'\' port=8000 open_viewer=False require_login=True secure=True

however the 5.6 appliance does not have thses lines but merely alias=sage-hg

Where do I alter the notebook launch to make the appliance launch for other users.