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Feb
10
comment Does NRoots own an abstract counterpart? If not, can we write one?
Any plan to implement the other 2 method of NRoots[]? Though I admit this question is motivated by my competitive mood against Matlab, now its target is to get the counterpart of NRoots[] anyway :)
Feb
10
comment Does NRoots own an abstract counterpart? If not, can we write one?
Translation for the comment of @chyaong: According to your new-added code, NRoots in v10.0.2 is more than 4 times as fast as that in v9.0.1. The roots[] in my answer has similar performance as roots() of matlab. Well, that's interesting.
Feb
10
comment Alternative to Series
Do you need a numeric series solution or a symbolic series solution?
Feb
10
comment Alternative to Series
I think you forgot 2 initial conditions in the code?
Feb
9
comment Does NRoots own an abstract counterpart? If not, can we write one?
@chyaong Yeah, list.x^Range[0, n] is simper, but Amita has chosen the latter and take the screenshot, so let it be, anyway it's not the main issue here :)
Feb
9
comment Precision of NIntegrate
You'd better add a concrete example. BTW, have you tried the WorkingPrecision option?
Feb
9
comment Does NRoots own an abstract counterpart? If not, can we write one?
@DanielLichtblau Yeah, and eliminating the preprocessing is the target of this question. I just edited the question and made this part clearer (I think).
Feb
9
comment Does NRoots own an abstract counterpart? If not, can we write one?
@DanielLichtblau That sounds reasonable. Question edited. (Thanks for the test from Amita!)
Feb
6
comment Does NRoots own an abstract counterpart? If not, can we write one?
To the downvoter, I am interested in what's wrong with my question, would you please elaborate. I'm not trying to complain here, I just want improve my question if possible.
Feb
3
comment Bug? Kernel Crash on SparseArray access
Confirmed in v8.0.4 and v9.0.1, vista 32bit.
Jan
31
comment NIntegrate and Integrate of a Spherical Bessel function
You misread OP's expression again, it should be BesselJ[15/2, BesselJZero[15/2, 1] r]^2 r
Jan
29
comment NIntegrate and Integrate of a Spherical Bessel function
Well, I'm afraid this isn't the integrand OP struggling with…
Jan
26
comment Brevity of denoting Conjugate[]
TraditionalForm?
Jan
24
comment Boundary sphere partial differential equation
Er… so what's your boundary condition of θ, in traditional math notation? BTW I think it'll be better if you mention some background information of your PDE.
Jan
22
comment Differential equation with a Heavisidetheta function running for ever
You've made a small mistake. y[L] == 0 and y''[L] == 0 can't be used in the first half as boundarys. If you Show the numeric and symbolic result, you'll see they're different :)
Jan
19
comment Least effort to handle a point source inside the domain of PDE(s)
Interesting……Well, does this mean if we stick a infinite thin rod on an unbroken membrane, the membrane won't have any displacement except on the stuck point?
Jan
17
comment VectorScale Explanation
I tried to improve the format and fix possible typo, if I misunderstood some part of your question, feel free to roll back… Well, with all due respect, as a member for 2 years, you should have format this question better.
Jan
17
comment One less arrow vector than asked for
Desired result in v8.0.4 and v9.0.1. I think it's reasonable to consider it as a bug.
Jan
17
comment Least effort to handle a point source inside the domain of PDE(s)
@Jens Yeah, that sounds reasonable. Maybe you can consider giving an answer?
Jan
16
comment The default ColorFunction of DensityPlot before v10?
@BrettChampion Oh……I see. You can make this into an answer, anyway it's not that obvious, I think.