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2015-04-24 00:01:23 +0200 asked a question Sage-mode typesetting problem

I am trying to start using emacs with sage-mode. After editing .emacs file to enable sage-mode and typsetting, I can see that even though the shell is working, the 'sage-view' option is not working propperly. In example, when typing the following text into the shell:

f(x) = x^2 ; f

The output is :

\newcommand{\Bold}[1]{\mathbf{#1}}x \ {\mapsto}\ x^{2}

I am a completley noob regarding emacs, and I have a feeling that the answer is somewhat very simple, but i couldn't find it on the web =/

Thanks in advance, David

2015-04-23 23:46:24 +0200 commented answer Loops get slower as they run

Thank you very much! I did learnt a lot from your answer =]

Sorry for the late response to your answer, actually I just now realized that i forgot to reply earlier

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2015-01-07 12:04:54 +0200 asked a question Sage loops becomes slower and slower on the run

Hello, I am trying to run a simulation in sage as part of my homework. The simulation itself is pretty fast and working fine. The problem starts when i try to run the simulation several times in a loop, then sage becomes incredibly slow in each repeat.

The program I wrote:

def poisson(lmu):
var('mu n')
g(mu,n)=(e^-mu * mu^n)/factorial(n)
num=random()
sum=g(lmu,0)

for i in xrange(1000):
    if num<sum:
        return i-1
    else:
        sum=sum+g(lmu,i)

def galtonwatson(mu,s,gens):
deaths=0
for i in range (gens):
    N=1
    n=0
    while n<s and N!=0:
        N=poisson(N*mu)

        n=n+1
    if N==0:
        deaths=deaths+1
return (deaths/gens).N()

both of the functions works fine, then telling sage to fill a list of 10 arrays with the values, and checking how much time it took for each repeat:

L=np.array([[0,0]for i in range(9)])
for i in xrange (9):
    t=time.time()
    print i
    L[i]= (i,galtonwatson(2,i,100)) 
    print (time.time()-t)

Sage output is:

0
0.000202894210815
1
0.393799066544
2
0.893945932388
3
1.54169392586
4
2.87310600281
5
4.84653711319
6
9.23449707031
7
18.3007540703
8
35.5397469997

It ain't the first time that sage loops becomes slower and slower on the run, and I could'nt understand the reason when searching the net.

Thanks in advanced, David

2015-01-07 12:01:41 +0200 asked a question Loops get slower as they run

Hello, I am trying to run a simulation in sage as part of my homework. The simulation itself is pretty fast and working fine. The problem starts when i try to run the simulation several times in a loop, then sage becomes incredibly slow in each repeat.

The program I wrote:

def poisson(lmu):
    var('mu n')
    g(mu,n)=(e^-mu * mu^n)/factorial(n)
    num=random()
    sum=g(lmu,0)

    for i in xrange(1000):
        if num<sum:
            return i-1
        else:
            sum=sum+g(lmu,i)

def galtonwatson(mu,s,gens):
    deaths=0
    for i in range (gens):
        N=1
        n=0
        while n<s and N!=0:
            N=poisson(N*mu)

            n=n+1
        if N==0:
            deaths=deaths+1
    return (deaths/gens).N()

both of the functions works fine, then telling sage to fill a list of 10 arrays with the values, and checking how much time it took for each repeat:

L=np.array([[0,0]for i in range(9)])
for i in xrange (9):
    t=time.time()
    print i
    L[i]= (i,galtonwatson(2,i,100)) 
    print (time.time()-t)

Sage output is:

0
0.000202894210815
1
0.393799066544
2
0.893945932388
3
1.54169392586
4
2.87310600281
5
4.84653711319
6
9.23449707031
7
18.3007540703
8
35.5397469997

It ain't the first time that sage loops becomes slower and slower on the run, and I could'nt understand the reason when searching the net.

Thanks in advanced, David