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 - 1212.12121212*Duty)*
(90909.0909091*Duty - 45454.5454545)*(s + 1058537.10173)) +
1053270.74799*s/(s*((s + 22.4212271973)*(s + 1058537.10173) +
127669181.574) - (606.060606061 - 1212.12121212*Duty)*
(90909.0909091*Duty - 45454.5454545)*(s + 1058537.10173)))*
(1212.12121212*Vb + 9.09090909091) - 90909.0909091*ILf*
(0.00497512437811*(1212.12121212*Duty - 606.060606061)*(s +
1058537.10173)/(s*((s + 22.4212271973)*(s + 1058537.10173) +
127669181.574) - (606.060606061 - 1212.12121212*Duty)*
(90909.0909091*Duty - 45454.5454545)*(s + 1058537.10173)) -
1053270.74799*(606.060606061 - 1212.12121212*Duty)/(s*((s +
22.4212271973)*(s + 1058537.10173) + 127669181.574) - (606.060606061 -
1212.12121212*Duty)*(90909.0909091*Duty - 45454.5454545)*(s +
1058537.10173)))
On Feb 24, 10:18 pm, Maurizio <maurizio.gran...@gmail.com> wrote:
> 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)?
>
> thanks
>
> Maurizio
>
> On 23 Feb, 09:35, Maurizio <maurizio.gran...@gmail.com> wrote:
>
> > 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 ( <class 'sage.calculus.calculus.SymbolicArithmetic'> )
>
> > (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*rCf + Lf*Rs) + rCf*rLf/(Lf*rCf + Lf*Rs) + Rs*rLf/(Lf*rCf +
> > Lf*Rs) + 2*Iin*rCb*rCf/(Lf*rCf + Lf*Rs) + Rs*rCf/(Lf*rCf + Lf*Rs) +
> > Rs*2*Iin*rCb/(Lf*rCf + Lf*Rs) + s) + Rs^2/((Cf*rCf + Cf*Rs)*(Lf*rCf +
> > Lf*Rs))) - (2*Duty/Cb - 1/Cb)*(1/Lf - 2*Duty/Lf)*(1/(Cf*rCf + Cf*Rs) +
> > s))) + Rs*s/((rCf + Rs)*(Cf*rCf + Cf*Rs)*(s*((1/(Cf*rCf + Cf*Rs) +
> > s)*(2*rCf*rQ/(Lf*rCf + Lf*Rs) + 2*Rs*rQ/(Lf*rCf + Lf*Rs) +
> > rCf*rLf/(Lf*rCf + Lf*Rs) + Rs*rLf/(Lf*rCf + Lf*Rs) +
> > 2*Iin*rCb*rCf/(Lf*rCf + Lf*Rs) + Rs*rCf/(Lf*rCf + Lf*Rs) +
> > Rs*2*Iin*rCb/(Lf*rCf + Lf*Rs) + s) + Rs^2/((Cf*rCf + Cf*Rs)*(Lf*rCf +
> > Lf*Rs))) - (2*Duty/Cb - 1/Cb)*(1/Lf - 2*Duty/Lf)*(1/(Cf*rCf + Cf*Rs) +
> > s)))) - 2*ILf*((2*Duty/Lf - 1/Lf)*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*rCf + Lf*Rs) + rCf*rLf/(Lf*rCf + Lf*Rs) + Rs*rLf/(Lf*rCf +
> > Lf*Rs) + 2*Iin*rCb*rCf/(Lf*rCf + Lf*Rs) + Rs*rCf/(Lf*rCf + Lf*Rs) +
> > Rs*2*Iin*rCb/(Lf*rCf + Lf*Rs) + s) + Rs^2/((Cf*rCf + Cf*Rs)*(Lf*rCf +
> > Lf*Rs))) - (2*Duty/Cb - 1/Cb)*(1/Lf - 2*Duty/Lf)*(1/(Cf*rCf + Cf*Rs) +
> > s))) - (1/Lf - 2*Duty/Lf)*Rs/((rCf + Rs)*(Cf*rCf + Cf*Rs)*(s*((1/
> > (Cf*rCf
> > + Cf*Rs) + s)*(2*rCf*rQ/(Lf*rCf + Lf*Rs) + 2*Rs*rQ/(Lf*rCf + Lf*Rs) +
> > rCf*rLf/(Lf*rCf + Lf*Rs) + Rs*rLf/(Lf*rCf + Lf*Rs) +
> > 2*Iin*rCb*rCf/(Lf*rCf + Lf*Rs) + Rs*rCf/(Lf*rCf + Lf*Rs) +
> > Rs*2*Iin*rCb/(Lf*rCf + Lf*Rs) + s) + Rs^2/((Cf*rCf + Cf*Rs)*(Lf*rCf +
> > Lf*Rs))) - (2*Duty/Cb - 1/Cb)*(1/Lf - 2*Duty/Lf)*(1/(Cf*rCf + Cf*Rs) +
> > s))))/Cb
>
> > and
>
> > params = [
> > rCf == 1*m_, Cf == 4.7*u_,
> > rCb == 10*m_, Cb == 22*u_,
> > rLf == 1*m_, Lf == 1.65*m_,
> > rQ == 10*m_,
> > Iin == 300/400,
> > Rs == 0.2,
> > Vrms == 220,
> > Vgr_pk == 220*sqrt(2),
> > ]
>
> > paramsd = {
> > "rCf" : 1*m_, "Cf" :4.7*u_,
> > "rCb" :10*m_, "Cb" :22*u_,
> > "rLf" :1*m_, "Lf" :1.65*m_,
> > "rQ" :10*m_,
> > "Iin" :300/400,
> > "Rs" :0.2,
> > "Vrms" :220,
> > "Vgr_pk" :220*sqrt(2),
>
> > }
>
> > NOTE: the m_, u_, etc. are just the multipliers previously defined in
> > a .sage file (m_ = 1e-3, u_ = 1e-6, etc.)
>
> > They are exactly the same subset
>
> > If I do
>
> > time dizSub = G_igr_d.subs(paramsd)
> > CPU time: 14.40 s, Wall time: 31.44 s
>
> > time G_id = subList(G_igr_d,params)
> > CPU time: 1.17 s, Wall time: 5.59 s
>
> > Why is it so? Please note that this has been done with SAGE : 'SAGE
> > Version 3.1.2, Release Date: 2008-09-19'
>
> > I've tried out this at home (but with simpler expressions) with the
> > latest SAGE, and the subs with the dictionary actually was faster.
>
> > Thank you
>
> > Maurizio
>
> > On Feb 21, 4:48 pm, Robert Bradshaw <rober...@math.washington.edu>
> > wrote:
>
> > > 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(expr, x=<value>) was SOOOO much
> > > > faster (are the dictionaries so slow to deal with?).
>
> > > > So, I implemented a subList function, where I can pass an expression,
> > > > and a list of substitution, in the very same way that the solve()
> > > > function returns the results.
>
> > > > So, now I put all my subsets of numerical values in list like this:
> > > > set = [x == 10, y == 20, z == 30, ...]
> > > > and do the substitution like this:
> > > > result = subList(expr, set)
>
> > > > Within the function, I just iterate the subs(expr, x = <value>) on the
> > > > number of list elements.
>
> > > > This seems to me much faster than using dictionaries, especially for
> > > > complex expressions.
>
> > > If this is the case, this is clearly a bug.
>
> > > - Robert
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