[sage-support] Re: plot 3d complex function

2010-09-04 Thread sps
On 3 Set, 23:40, Marshall Hampton hampto...@gmail.com wrote: Here's a slightly different workaround that doesn't require any lambda expressions: var('z,z0,x,y') f=abs(1/(z-z0)).subs({z:x+I*y,z0:1/2+i}) ff = fast_callable(f,vars=[x,y],domain=CDF) plot3d(ff,(x,-2,2),(y,-2,2)) -Marshall

Re: [sage-support] Re: plot 3d complex function

2010-09-04 Thread Minh Nguyen
Hi, On Sat, Sep 4, 2010 at 7:01 PM, sps debernasave...@libero.it wrote: But what is fast_callable function ? Where can I find adaguate documentation? See this page in the reference manual

[sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread ma...@mendelu.cz
What about to use polynomial division to get polynomial q=Q/p and then return P/q ? I do not remember the command for polynomial division, but should be in the manual or help. Robert On 4 zář, 05:54, Cary Cherng cche...@gmail.com wrote: I have a rational function P(x)/Q(x) with numerators and

[sage-support] sticking matricies together

2010-09-04 Thread andrew ewart
How do u stick a matrix on the bottom of antoher martix, in particular the identity matrix so if had M (l,k) how do I stick Id(k) on the bottom to produce a new matrix N=M and N is dimension (l+k,k) Id -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe

Re: [sage-support] sticking matricies together

2010-09-04 Thread Robert Bradshaw
On Sat, Sep 4, 2010 at 8:15 AM, andrew ewart aewartma...@googlemail.com wrote: How do u stick a matrix on the bottom of antoher martix, in particular the identity matrix so if had M (l,k) how do I stick Id(k) on the bottom to produce a new matrix N=M   and N is dimension (l+k,k)    Id Look

Re: [sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Robert Bradshaw
On Sat, Sep 4, 2010 at 3:25 AM, ma...@mendelu.cz ma...@mendelu.cz wrote: What about to use polynomial division to get polynomial q=Q/p and then return P/q ? I do not remember the command for polynomial division, but should be in the manual or help. If Q and p are polynomials, polynomial

[sage-support] matrix questions

2010-09-04 Thread andrew ewart
if a have a matrix M of dimension (m,n) how do i first check for j columns deep (from left), j=n for when the ith row will be all zeros eg M=([1,0,1],[0,0,1],[1,1,1]) check j=1 gives output of 1 j=2 gives output of 1 and j=3 gives output of 3 also how do i take out a matrix N of dimension (k,l)

[sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Cary Cherng
I should have given the original full context. These polynomials P,Q, and p are all in Z[x1,...,xn]. They are all multivariate. On Sep 3, 8:54 pm, Cary Cherng cche...@gmail.com wrote: I have a rational function P(x)/Q(x) with numerators and denominators of very large degree. From the context I

[sage-support] Re: Implication

2010-09-04 Thread tvn
HI Jason, I tried what you posted and get some errors , I am using the latest Sage version 4.5.2 -- | Sage Version 4.5.2, Release Date: 2010-08-05 | | Type notebook() for the GUI, and license() for

[sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Cary Cherng
And thats another problem. How do I tell sage to give me the denominator of this rational function? On Sep 4, 3:25 am, ma...@mendelu.cz ma...@mendelu.cz wrote: What about to use polynomial division to get polynomial q=Q/p and then return P/q ? I do not remember the command for polynomial

Re: [sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Justin C. Walker
On Sep 4, 2010, at 13:54 , Cary Cherng wrote: And thats another problem. How do I tell sage to give me the denominator of this rational function? In general, the .denominator and .numerator methods will (should) give you the components of a rational element. HTH Justin -- Justin C.

[sage-support] Re: matrix questions

2010-09-04 Thread Jason Grout
On 9/4/10 12:56 PM, andrew ewart wrote: if a have a matrix M of dimension (m,n) how do i first check for j columns deep (from left), j=n for when the ith row will be all zeros eg M=([1,0,1],[0,0,1],[1,1,1]) check j=1 gives output of 1 j=2 gives output of 1 and j=3 gives output of 3 I realize

[sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Cary Cherng
.denominator() gave me 1. Sage prints out the rational function as R1 + .. + R2 where Ri is a rational function and each having a different denominator. Sage doesn't seem to be automatically writing this as one fraction with a common denominator, could that be the reason it is returning 1 for the

[sage-support] Re: Implication

2010-09-04 Thread Simon King
Hi! On 4 Sep., 22:52, tvn nguyenthanh...@gmail.com wrote: HI Jason,  I tried what you posted and get some errors , I am using the latest Sage version 4.5.2 -- | Sage Version 4.5.2, Release Date: 2010-08-05                    

[sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Cary Cherng
Ok i think I've resolved my problems by avoiding var for declaring variables and instead using R.g17,g19,g27,g29,g37,g38,g47,g48,g58,g59,g68,g69 = PolynomialRing(QQ) -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to

Re: [sage-support] Re: Factoring denominator of a rational function

2010-09-04 Thread Robert Bradshaw
On Sat, Sep 4, 2010 at 7:00 PM, Cary Cherng cche...@gmail.com wrote: Ok i think I've resolved my problems by avoiding var for declaring variables and instead using R.g17,g19,g27,g29,g37,g38,g47,g48,g58,g59,g68,g69 = PolynomialRing(QQ) Yes, that should be orders of magnitude faster than doing