Larry Moss's profile - activity

Thanks very much for all of this! This should go a long way towards doing what I need to do here.

Thanks for engaging with this. It's a .py document, but I am not sure why it's listed that way: I wrote it in Sage several years ago, and I think it originally was a .sagews file.

I did share the file with you just now.

Among the issues that I'm having:

(1) Declarations like

var('skunks', 'rabbits', 'quadrupeds', 'deer', 'pests', 'beautiful_creatures', 'ugly_creatures', 'birds', 'bats', 'horses', 'ducks', 'pos', 'neg')

(2) the use of 'exists' and 'forall' in dealing with lists

(3) the use of graph operations like making graphs with DiGraph, and also matrix opearations that are native here that might require a package in Python.

Thanks for engaging with this. It's a .py document, but I am not sure why it's listed that way: I wrote it in Sage several years ago, and I think it originally was a .sagews file.

I did share the file with you just now.

Among the issues that I'm having:

(1) Declarations like

var('skunks', 'rabbits', 'quadrupeds', 'deer', 'pests',
    'beautiful_creatures', 'ugly_creatures', 'birds', 'bats', 'horses',
    'ducks', 'pos', 'neg')

(2) the use of 'exists' and 'forall' in dealing with lists

(3) the use of graph operations like making graphs with DiGraph, and also matrix opearations that are native here that might require a package in Python.

I'd expect that (1) and (2) will be straightforward to change by hand, and I'm wondering if there are automatic resources for them. I know that for special built-ins for sage that will require some package in Python, I'm probably out of luck.

I have a CoCalc notebook running a SageMath program. What I have runs under SageMath 9.1. Someone wants to include my stuff in a Python work environment. So the first step is to convert it to Python. I tried 'preparse', but that doesn't seem to work from the terminal window.

Is there a working automatic translation to help with this conversion?

Thanks -- the point about one technology for my students is a good one.

I'm making a few notebooks for educational use and I'm looking for guidance as to what I should be using: a sage worksheet running Jupyter, or a Jupyter notebook. For the most part, I want users to be able to run existing Python programs.

(I also want them to run some Haskell programs, and for this, the choice is clearer: I want the Jupyter notebook because I can set the mode to Haskell.)

I don't see anything here that offers comparisons, and so here are some of the issues on my mind.

I find the Jupyter notebook cell system more to my liking than a sagews. I believe that users would also, but I have no real experience with that.

I think there's more documentation here for the sagews (right?), but there's more out there on the Jupyter notebook.

I'd like some support for simple tables containing text and numbers; nothing fancier. Is there a difference there?

A final issue: is there any difference in terms of displaying html, either in the application itself or in separate windows?

And on a related point: what is the difference between a sagews set up to run a Jupyter kernel via

py3 = jupyter("python3")

and one via

a3 = jupyter("anaconda3")

Is this an orthogonal issue, or is it related to my overall question?

In the Edit menu, I see options "Toggle write protection" and "Toggle delete protection". Is there a way to make the locked versions the default? I am preparing notebooks for others to use, and so I'd like most of the cells to be locked for for deletion and over-writing.

I figure that there's a configuration file for cells somewhere, but I don't know where it is.

On the pulldown Edit menu, I see 'Toggle write protection' and 'Toggle delete protection'. Is there a way to make the locked option the default, so that the toggling only needs to be done to permit writing or deleting?

The reason I ask is that I'm preparing a notebook for others to use, so I want most of the cells to be locked both ways.

I figure there's a default configuration setting, but I don't know where it would be.

Thanks! But did you fix a bug in my code or in sage? If the bug is with me, I should know so this doesn't happen again. After all, *you* are the one with psychic abilities; I have none. Thanks again -- Larry

I have some code that does fine on my local machine, and it used to work on cloud.sagemath, but currently it gives an error. The error is listed below. I believe that it has to do with the declaration of variables at the top of my worksheet.

But again, copying this to my local installation doesn't give the error.

Thanks!

Error in lines 14-56
Traceback (most recent call last):
  File "/projects/4f1d0d75-55b1-4a27-a977-593efeabe994/.sagemathcloud/sage_server.py", line 828, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "", line 2, in initialize
  File "", line 2, in ina
  File "/projects/4f1d0d75-55b1-4a27-a977-593efeabe994/.sagemathcloud/sage_salvus.py", line 2633, in var
    return var0(*args, **kwds)
  File "/projects/4f1d0d75-55b1-4a27-a977-593efeabe994/.sagemathcloud/sage_salvus.py", line 2605, in var0
    v = sage.all.SR.var(*args, **kwds)
  File "ring.pyx", line 595, in sage.symbolic.ring.SymbolicRing.var (build/cythonized/sage/symbolic/ring.cpp:7887)
TypeError: var() takes at most 3 positional arguments (18 given)

Thanks very much!

sage.logic.propcalc allows one to see if a sentence in propositional logic is satisfiable.

The documentation has

sage: f = propcalc.formula("a|b")
sage: f.is_satisfiable()
True

Is there a syntax that would give a satisfying assignment? I'd like something like

sage: f.is_satisfiable(show)
a:=True, b:=True

The documentation doesn't give the syntax, but I'm betting it's there somewhere.

I think I've had this problem both ways. I just tried it again, and so here's what happened exactly. I was working on http://www.sagenb.org/home/Larry_Moss/3/#, I asked for a new worksheet, and I got http://www.sagenb.org/home/Larry_Moss/9/, but with the option to change then name from 'untitled'. There doesn't seem to be a way for me now to get an absolutely new worksheet.

I'm using the sagenb server, and when I ask for a New Worksheet, here's what happens:

The last worksheet I've used appears, not a new one, and then I'm offered a chance to change its name.

Is there a bug somewhere, either with me or the server?

Thanks. When you email, do you also need to give any special instructions on what to do with the sws file?

I have a worksheet that I'd like to share with a class, so that they can do some further calculations with what I did. I'm wondering what the best way to do that is. I know that if I 'publish' it, nothing really happens, since this kind of sharing is currently enabled. It's too late for me to arrange a server here for this semester. Do I have any good options?

I am looking for a module having to do with preorders (sets with reflexive and transitive relations, also called quasi-orders). I'd like to use a few of the poset methods on preorders, but this doesn't seem to work. That is, I get

Traceback (click to the left of this block for traceback) ... ValueError: Hasse diagram contains cycles.

I figure that either there is a way to indirectly use the poset methods on preorders more generally, or else someone has implemented the quotient operation. (This turns a preorder (A,\leq) into a poset by taking the quotient under the equivalence relation \equiv on A by a \equiv b iff a \leq b and b \leq a.