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RSS Feed for Wolfram Community showing any discussions in tag Physics sorted by active[✓] Solve coupled differential-algebraic equations (Stiff-system suspected)
http://community.wolfram.com/groups/-/m/t/1167637
I am trying to plot a graph between eta and tau using NDSolve method . But i am getting the message at output 'Stiff-system suspected'.
Kindly help me to solve the problemshivi sv2017-08-20T09:32:41Z[✓] Calculate Bessel Function zeros? (Can PayPal for solution)
http://community.wolfram.com/groups/-/m/t/1165759
I am working on a drum synthesizer based off the Bessel Function zeros. (The modal frequencies of a circular drum membrane are predicted by the Bessel Function zeros.)
To built it, I have been manually calculating Bessel zeros using Casio's calculator:
http://keisan.casio.com/exec/system/1180573472
This is working. However, it is very slow work, as I am calculating each zero one by one, manually.
Bessel equations in Wolfram are incredibly easy by contrast. How they work is summarized here:
http://mathworld.wolfram.com/BesselFunctionZeros.html
> the Bessel function ![enter image description here][1] for nonnegative integer values of n and k can be found in the Wolfram Language using the command BesselJZero[n, k].
In an ideal world, I'd like bessel zeros to 6 significant digits for, n = 0...99 and k = 1...100. This would produce a table or list of 10,000 Bessel zeros.
If it is easy, can anyone here maybe do me a huge favor and punch these into your Wolfram Language system to produce a table or list you can share? I would be happy to PayPal you $20 for your effort if so. If it's more work than that, let me know what it would cost.
Otherwise, how would I set up my Windows system to do this? Can I work with Wolfram Language from Windows? I don't have a Raspberry Pi.
I've calculated 1200 of these things manually which as you can imagine has been very tedious. While I'm getting the results I want, I will likely need at least 2000 more to get truly realistic results. I'd hate to spend days and weeks manually working out Wolfram can spit out in 5 minutes!
In an ideal world, I'd like a table like this in Excel or any other workable format:
![enter image description here][2]
Very hopeful for any help. Thank you very much.
Mike
[1]: http://community.wolfram.com//c/portal/getImageAttachment?filename=Inline16.gif&userId=1165745
[2]: http://community.wolfram.com//c/portal/getImageAttachment?filename=wolframbessels.PNG&userId=1165745Michael M2017-08-16T04:54:28ZDoes "FindRoot" work with numerical functions?
http://community.wolfram.com/groups/-/m/t/1158470
I have a problem with FindRoot, I want to find the root of a function but it consist of two parts, an analytical function and a numerical function, for example: imagine I have f1(x)= x that's my analytical function but the other one it doesn't depends on a variable it just print me a number when I call it, if I do f2(1.2)=5.6 for say something, but i can not do f2(x) that is not how is built my second function, it doesn't have a known shape because is quite complicated so is a numerical approach.
The thing is I want to solve this two equations for Liquid-Vapor equilibrium, there are 2 equations and this two depend on two functions, one analytic ant the other numeric, as I explained before, I don't show how they depend because the code is large and complicated, but in the document I attached, you can see in a good way what I want to solve.
p[ T, \[Rho]V] == p[ T, \[Rho]L],
\[Beta]\[Mu][ T, \[Rho]V] == \[Beta]\[Mu][ T, \[Rho]L]
Thank you and I hope you understood my problem.Charls Mejía2017-08-04T03:06:08Z