PatB's profile - activity

Merci Emmanuel pour vos précisons! C'est bien expliqué! Pat

Thanks Max, So the answer is: A*w is well defined because the vector w assumes the column form to complete the operat

Tutorial example matrix multiplication Hi, I'm looking at the tutorial linear algebra: We have sage: A = Matrix([[1,2

Thanks very much John - good catch!

The method lim() does not return a simple integer Hi, I have two cases where I would expect the answer to be a simple

The method lim() does not return a simple integer Hi, I have two cases where I would expect the answer to be a simple

Un gros MERCI Ricardo. That is a great fix! It worked in a context of a more subtle nature: I had to declare an index e

Un gros MERCI Ricardo. That is a great fix! It worked in a context of a more subtle nature: I had to declare an index e

Cannot index an array - causing key error , context astropy.io There seems to be a problem indexing the object class 'as

Un gros merci Ricardo! The sage pip install worked - for python2.7. Yes, I should be ashamed to use this 4 year old sag

import astropy in a sage notebook v Hi Sagesse! I'm wondering if there's an easy way to get a sage notebook (v8.7) to i

Merci encore, il y a toujours un moyen... il faut s'habituer aux objets comme AA, RR,RDF :)

Un gros MERCI Emmanuel! I got the solution I needed for the 3rd part of this piecewise funtion (it agrees with mathema

solving 2 non-linear functions (max degree of 3) fails I'm having trouble solving the following: It's a simple system

solving 2 non-linear functions (max degree of 3) fails I'm having trouble solving the following: var('k','r','c') r = 0

solving 2 non-linear functions (max degree of 3) fails I'm having trouble solving the following: var('k','r','c') r = 0

Yes, that makes perfect sense!

I need to create a reference to this combined object - as you suggested mQ = m+Q allows me to do mQ.set_axes_range(...)

Merci Beaucoup! Une réponse le jour même de Noël!

I have created a matrix plot and a line and combined them as follows:

m = matrix_plot([[1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0]],
                aspect_ratio=1,
                frame=False)
Q = line([(-0.5, 0), (1, 1)], thickness=3)

Combined graphics is (m+Q).

I would like to change the size of (m+Q), but (m+Q).set_axes_range() does not affect the values.

Here is an example showing no change when using set_axes_range():

• https://sagecell.sagemath.org/?q=wnkqye

What method should I use?

Hi, I naively created a chess board with a matrix_plot.

m = matrix_plot([[1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0],
                 [0,1,0,1,0,1,0,1],
                 [1,0,1,0,1,0,1,0]]
                  )

Shown alone, it looks almost like a chess board, but it has axes and white padding on the periphery

 (m).show(aspect_ratio=1)

I then naively tried to add a line to that plot -

Q = line([(-0.5,0),(1,1)])
(m+Q).show()

Somehow I have lost the whole matrix plot . This is version 8.7 in a jupyter notebook

Q = line([(-0.5,0),(1,1)])
(m+Q).show()

i only get 2 rows - the rest is truncated.

Question - how to graph lines on top of this matrix plot without truncating the apprearance?

Merci! Pat

Hi Folks,

Has anyone tried to do some harmonic or rythm analysis for musical instruments using sage?

Also - how easy is it under ubuntu to produce sounds of these harmonics?

Any links will be appreciated.

thanks Pat

Hi folks,

I tried running notebook(require_login=False) .... which produced an error and probably as a side-effect deleted the "lock" file I was looking for with the defunct pid.

Then I restarted the notebook() and it works... The terminal message told me: Executing twistd --pidfile="sage_notebook.sagenb/sagenb.pid" -ny "sage_notebook.sagenb/twistedconf.tac"

I then checked :~/.sage/sage_notebook.sagenb for sagenb.pid .... this file contained 3800 --- which is the currently running server.

So I suspect that if I get this problem again, alls I need to do is delete this "lock" file.

Eh bien!

Pat

Hi Sage users

It looks like a system crash left a lock file for a sage notebook server. I cannot run the notebook: Another Sage Notebook server is running, PID 2128. Opening web browser at http://localhost:8080/ ...

Does anyone know where this lock file is or what the procedure is to clear up this error? I have no PID 2128 running at the time this error occurs. Hence I think it is some lock file or ressource that needs to be freed or deleted. Thanks Pat

Hi Thanks for getting back to me. I'm looking to create various nets of stellations of the icosahedron as shown here for example: https://en.wikipedia.org/wiki/Stellat... I discovered this in Wenninger's book Polyhedron Models - number 27 shows the Second Stellation of the icosahedron - very beautiful. Mathworld shows the first stellated form of the isocasehdron the Triakis Icosahedron and provides a net for it http://mathworld.wolfram.com/TriakisI.... Can we do that in sage? Pat

Hi Sagists, I'm wondering if anyone knows a way to do stellation with the Polyhedron class? Mathematica has a Stellate function but they admit it is really an augment operation and not a true stellation thanks Pat Browne

Is there a way to specify a stopping rule or condition like r[t] < rMin when integrating?

Here's an example in Mathematica:

s = NDSolve[{r''[t] == -GM / r[t]^2, r[0] = 1000 * s0, r'[0] = 0,
             WhenEvent[r[t] < rMin, "**StopIntegration**"]}, r, {t, 0, 86400 * 100}]

Hi, I'm plotting arcs, and they're not doing what I want. When I try to examine them the information is hidden behind the message Graphics object consisting of 1 primitive. How do I find out what the arc object contains?

thanks ./pat

Hi Folks, I'm curious - I could help do the documentation patch - but not sure if I'm allowed. Once that is done, I'd be happy to "Answer my own question" by citing the documentation, and then we could say the case is closed... So how can I help?