[sage-devel] Re: reusing solutions in functions

2009-03-08 Thread Maurizio
Hello, I was able to reproduce this in Sage 3.3 var('a b c') first = a + b + c first._operands[0]._operands[0] is a True second = loads(dumps(first)) second._operands[0]._operands[0] is a False Should anyone open a bug in trac? I am not sure of how to do that and which function to address th

[sage-devel] Re: reusing solutions in functions

2009-02-27 Thread Kenny
Sorry... i forgot to display the results: + True + False That means the bug is in the dump or the load function! On Feb 27, 10:33 am, Kenny wrote: > I've  took a look a the example code, and so I think that the bug is > in the dumps and load function: > > var('Rs') > mio = Rs + Rs*Rs + sqrt(10

[sage-devel] Re: reusing solutions in functions

2009-02-27 Thread Kenny
I've took a look a the example code, and so I think that the bug is in the dumps and load function: var('Rs') mio = Rs + Rs*Rs + sqrt(10) tuo=loads(dumps(mio)) print mio._operands[0]._operands[0] is Rs print tuo._operands[0]._operands[0] is Rs IAt this time I've not looked inside the code, but

[sage-devel] Re: reusing solutions in functions

2009-02-27 Thread Maurizio
Carl, you were totally right. The results are matching your previsions. I get: var('Cb') G_igr_d._operands[1]._operands[1] is Cb False G_works = SR(repr(G_igr_d)) time G_works.subs(paramsd) Time: CPU 0.16 s, Wall: 0.86 s I add now another aspect: the G_igr_d is symbolically evaluated in ano

[sage-devel] Re: reusing solutions in functions

2009-02-26 Thread Carl Witty
On Wed, Feb 25, 2009 at 2:33 PM, Maurizio wrote: > Is it a problem interfacing to any symbolic package different from the > ordinary maxima one? I don't exactly recall if I took advantage of > others. OK, I spent some time looking at this, and this may indeed be the problem. I have a workaround

[sage-devel] Re: reusing solutions in functions

2009-02-26 Thread Carl Witty
On Thu, Feb 26, 2009 at 9:26 AM, Maurizio wrote: > > You are certainly very kind. > I really appreciate your help. I'm going to email you the expressions. The files are now available at http://sage.math.washington.edu/home/cwitty/slow-substitution/ I won't be able to look at them until this even

[sage-devel] Re: reusing solutions in functions

2009-02-26 Thread Maurizio
You are certainly very kind. I really appreciate your help. I'm going to email you the expressions. Thank you On 26 Feb, 18:15, Carl Witty wrote: > On Thu, Feb 26, 2009 at 12:26 AM, Maurizio wrote: > > > Carl, > > I should thank you in advance for your great help. > > > Unfortunately, the dump

[sage-devel] Re: reusing solutions in functions

2009-02-26 Thread Carl Witty
On Thu, Feb 26, 2009 at 12:26 AM, Maurizio wrote: > > Carl, > I should thank you in advance for your great help. > > Unfortunately, the dumps test doesn't improve the result: > > time test = loads(dumps(G_igr_d.subs(paramsd))) > Time: CPU 13.32 s, Wall: 33.21 s > > Moreover, I'm working from the

[sage-devel] Re: reusing solutions in functions

2009-02-26 Thread Maurizio
Carl, I should thank you in advance for your great help. Unfortunately, the dumps test doesn't improve the result: time test = loads(dumps(G_igr_d.subs(paramsd))) Time: CPU 13.32 s, Wall: 33.21 s Moreover, I'm working from the notebook, so I am not able to get the backtrace by interrupting the

[sage-devel] Re: reusing solutions in functions

2009-02-25 Thread Carl Witty
On Wed, Feb 25, 2009 at 2:33 PM, Maurizio wrote: > > Carl, > this is certainly reasonable, but maybe a little unfeasible. ... > Can you derive some information from this description, or has this > been useless? Maybe I can provide something like the last part of the > notebook, placing some inter

[sage-devel] Re: reusing solutions in functions

2009-02-25 Thread Maurizio
Carl, this is certainly reasonable, but maybe a little unfeasible. The reason is that, I use some scripts of mine in the process of the evaluation, and the whole process is pretty long. The algorithm basically starts from a couple of linear systems of equations; they are solved, and from the sol

[sage-devel] Re: reusing solutions in functions

2009-02-25 Thread Carl Witty
On Wed, Feb 25, 2009 at 11:05 AM, Maurizio wrote: > So I manually write down the same expression in a new variable, I get: > > time dizTemp = temp.subs(paramsd) > Time: CPU 0.01 s, Wall: 0.01 s > > And temp and G_igr_d have the same type!! > > Where can the lag arise from? This seems really subtl

[sage-devel] Re: reusing solutions in functions

2009-02-25 Thread Maurizio
Thank you very much Yann!! Today I upgraded to SAGE 3.3, to check if there was an improvement, but I had the very same results than before. Now I see this strange behaviour: time dizSub = G_igr_d.subs(paramsd) Time: CPU 10.64 s, Wall: 21.53 s But if I do: var('s') temp = (2*Iin*rCb/Lf + 2*Vb/L

[sage-devel] Re: reusing solutions in functions

2009-02-24 Thread YannLC
If I try your example at home with sage-3.3, I obtain: sage: time dizSub=G_igr_d.subs(paramsd) CPU times: user 0.03 s, sys: 0.00 s, total: 0.03 s Wall time: 0.03 s sage: dizsub (0.00497512437811*s*(s + 1058537.10173)/(s*((s + 22.4212271973)*(s + 1058537.10173) + 127669181.574) - (606.060606061 -

[sage-devel] Re: reusing solutions in functions

2009-02-24 Thread Maurizio
excuse me guys, I didn't want to bother you with my long example (I thought that could be a good idea to give something reproducible) , but can you at least tell me some reason why in my case the subs with the dictionary is so slow (especially with respect to the substitution with equations)? tha

[sage-devel] Re: reusing solutions in functions

2009-02-23 Thread Maurizio
People, please let me understand this! Let me give you my example so that you can help me recognizing where is my mistake I've this function: G_igr_d ( ) (2*Iin*rCb/Lf + 2*Vb/Lf)*(s*rCf*(1/(Cf*rCf + Cf*Rs) + s)/((rCf + Rs)*(s*((1/(Cf*rCf + Cf*Rs) + s)*(2*rCf*rQ/(Lf*rCf + Lf*Rs) + 2*Rs*rQ/(Lf*r

[sage-devel] Re: reusing solutions in functions

2009-02-21 Thread Robert Bradshaw
On Feb 21, 2009, at 3:30 AM, Maurizio wrote: > That was the way I used to do it when I discovered the solution_dict > param. > > So, I started using the dictionaries to do substitution even in > complex expressions... The result was to wait so much time! > > On the contrary, I found that the subs

[sage-devel] Re: reusing solutions in functions

2009-02-21 Thread Harald Schilly
On Feb 21, 12:30 pm, Maurizio wrote: > So, I started using the dictionaries to do substitution even in > complex expressions... The result was to wait so much time! That sounds bad, can you give an example? Or create one so that others can investigate it? > result = subList(expr, set) I still

[sage-devel] Re: reusing solutions in functions

2009-02-21 Thread Maurizio
That was the way I used to do it when I discovered the solution_dict param. So, I started using the dictionaries to do substitution even in complex expressions... The result was to wait so much time! On the contrary, I found that the subs(expr, x=) was S much faster (are the dictionaries so

[sage-devel] Re: reusing solutions in functions

2009-02-20 Thread Robert Bradshaw
On Feb 19, 2009, at 2:43 PM, Harald Schilly wrote: > > On Feb 19, 10:18 pm, Mike Hansen wrote: >> I'd do something like this: > > yes, thanks. it's just not very intuitive because you have to know the > solution_dict parameter in advance. i don't know, but it would be > interesting if a syntax l

[sage-devel] Re: reusing solutions in functions

2009-02-20 Thread rjf
Maxima's solve sometimes produces answers (assuming they can be found) as lists of equations, e.g. [x=a,y=b]. The syntax for substitution has several versions. subst(3,x,x+y) ---> y+3. subst(x=3,x,x+y) subst([x=3,y=4],x+y) --> 7 Solve can also produce systems of solutions, e.g. sols

[sage-devel] Re: reusing solutions in functions

2009-02-19 Thread Harald Schilly
On Feb 19, 10:18 pm, Mike Hansen wrote: > I'd do something like this: yes, thanks. it's just not very intuitive because you have to know the solution_dict parameter in advance. i don't know, but it would be interesting if a syntax like f(sol[0]) could be implemented - or does it have too many si

[sage-devel] Re: reusing solutions in functions

2009-02-19 Thread Mike Hansen
On Thu, Feb 19, 2009 at 1:08 PM, Harald Schilly wrote: > > In IRC I had a question and I don't know how to do it ... > > If you have a solution of an equation, how to apply the result to a > function? > > sage: var('x y') > (x, y) > sage: solve([x+y==6, x-y==4], x, y) > [[x == 5, y == 1]] > sage