hello,
why is the below code plotting a flat function rather than a box one?
renato
def box(x,c):
if abs(x) < c:
return 1
else:
return 0
var('x')
plot(box(x,1),(x,-3,3))
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On Fri, Feb 4, 2011 at 11:37 AM, Renato Budinich wrote:
> hello,
> why is the below code plotting a flat function rather than a box one?
When you do,
> plot(box(x,1),(x,-3,3))
it evaluates box(x,1) which returns 0 because the variable x is not
always less than 1. You need to delay the evaluati
> hello,
> why is the below code plotting a flat function rather than a box one?
There are two things going on. First, in the line
plot(box(x,1),(x,-3,3))
box(x,1) is actually being evaluated when the line is executed, and
not thereafter. IOW you're computing box(x, 1), which is 0, so the
abov
I am trying to build Sage 4.6.1. on Ubuntu 10.10 notebook with
Intel(R) Core(TM) i5 CPU M 430 @ 2.27GHz.
I installed all prerequisites, and did
export MAKE="make -j5"
export SAGE_CHECK="yes"
make
which produced error message ending with
323 tests OK.
2 tests failed:
test_distutils test_zlib
On Fri, 4 Feb 2011 19:40:34 +0800
"D. S. McNeil" wrote:
> > hello,
> > why is the below code plotting a flat function rather than a box
> > one?
>
> There are two things going on. First, in the line
>
> plot(box(x,1),(x,-3,3))
>
> box(x,1) is actually being evaluated when the line is executed
plot(lambda x: box(x,1), (x, -3, 3))
but why does this way the execution of the function get delayed?
because lambda is a way to define a function.
This works more or less like the following :
def MyFunction(x)
return box(x,1)
plot(MyFunction,(x,-3,3))
See for example
http://www.sec
Mate Kosor wrote:
I am trying to build Sage 4.6.1. on Ubuntu 10.10 notebook with
Intel(R) Core(TM) i5 CPU M 430 @ 2.27GHz.
I installed all prerequisites, and did
export MAKE="make -j5"
export SAGE_CHECK="yes"
make
Don't set export SAGE_CHECK="yes"
This will fail as you noted.
Jaap
--
To po
I can't produce something completely replicable on this, but the
'published' version of a worksheet I put up the other day was
definitely older than the one I had saved (and it did save,
thankfully).Has anyone had any problems with a 'published'
worksheet looking like a previous version of a wo
On Friday, February 4, 2011 8:50:38 AM UTC-8, jaapspies wrote:
>
> Mate Kosor wrote:
> > I am trying to build Sage 4.6.1. on Ubuntu 10.10 notebook with
> > Intel(R) Core(TM) i5 CPU M 430 @ 2.27GHz.
> > I installed all prerequisites, and did
> > export MAKE="make -j5"
> > export SAGE_CHECK="yes"
Dear Martin,
Many thanks for these explanations...
They point exactly what I was looking for.
a very last question : Is there a link between
ring structure GF(2)[a,b,c] / (a^2-a, b^2-b, c^2-c) where + == xor and *
== and
and Boolean predicates over variables a, b, c with operators "or == |"
Hi, I know of no elegant way of doing that. There are a few ANF
(polynomials) to CNF (ORs and ANFs) strategies which are used for example in
cryptography. Those might be of interrest to you. I have a few pointers in
my thesis.
Cheers,
Martin
On Feb 4, 2011 6:12 PM, "Francois Maltey" wrote:
--
T
Hi all,
I still have not found a solution to this problem. Can anyone help?
Thanks,
Chris
On Jan 26, 5:24 pm, "C. Kelly" wrote:
> Hi all,
>
> I define the following one-parameter functions and their derivatives
>
> x,y,l,L = var('x,y,l,L')
>
> d5 = function('d5',nargs=1)
>
> def d3partderiv(sel
Hi, just FYI.
Cleaning up various old notebook files, I came across the following
Benchmark.
It seems that overall version 4.6 is faster, but not for all
tests.
3.4 4.6 Benchmark
0.4s0.4sFactor the following polynomial over the rational numbers:
(x^97+19*x+1)*(x^103-19*x^97+14)*(x^
C. Kelly wrote :
I define the following one-parameter functions and their derivatives
x,y,l,L = var('x,y,l,L')
d5 = function('d5',nargs=1)
def d3partderiv(self,*args,**kwds): arg = args[0]; return
L*L*d5(arg);
d3 = function('d3',derivative_func=d3partderiv)
def d1partderiv(self,*args,**kwds):
Hello, I came back...
I define the following one-parameter functions and their derivatives
x,y,l,L = var('x,y,l,L')
d5 = function('d5',nargs=1)
def d3partderiv(self,*args,**kwds): arg = args[0]; return
L*L*d5(arg);
d3 = function('d3',derivative_func=d3partderiv)
def d1partderiv(self,*args,**k
On Feb 4, 6:38 am, Mate Kosor wrote:
> I am trying to build Sage 4.6.1. on Ubuntu 10.10 notebook with
> Intel(R) Core(TM) i5 CPU M 430 @ 2.27GHz.
> I installed all prerequisites, and did
> export MAKE="make -j5"
> export SAGE_CHECK="yes"
> make
> [...]
Aside: This probably won't make any differe
Hi list
how can i add a new edge (a->b) to a given graph G (n.n. connected),
just in the case that there is no path (a -> ... -> b) before?
all i found is the all_path(a,b) method wich tooks very long in my case
and generates a huge overhead.
greatz Johanens
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On Fri, Feb 4, 2011 at 11:56 PM, Johannes wrote:
> Hi list
> how can i add a new edge (a->b) to a given graph G (n.n. connected),
> just in the case that there is no path (a -> ... -> b) before?
You should use "shortest_path" which uses Dijkstra's algorithm under the hood.
if g.shortest_path('a'
On Fri, Feb 4, 2011 at 3:26 PM, Mike Hansen wrote:
> On Fri, Feb 4, 2011 at 11:56 PM, Johannes wrote:
>> Hi list
>> how can i add a new edge (a->b) to a given graph G (n.n. connected),
>> just in the case that there is no path (a -> ... -> b) before?
>
> You should use "shortest_path" which uses
>
> how can i add a new edge (a->b) to a given graph G (n.n. connected),
> just in the case that there is no path (a -> ... -> b) before?
>From your question, I can not infer whether you are dealing with directed or
undirected graphs. So just in case :
- If your graph is undirected and there a
>
> Of course finding the shortest path may be (almost) as expensive as
> finding all of them... If you're doing this for a lot of edges you
> might want to break it up into components, then the test would be
> easy. It would be cool if all_paths were an iterator and you could
> just ask for the f
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