Maple 2016 Questions and Posts

These are Posts and Questions associated with the product, Maple 2016

Here is one that the students generated which caused confusion. 

a := 0.76;
eq1 := 2*cot(a*sqrt(2*E)) = (2*E-5.4)/(sqrt(E*(5.4-E));
solve(eq1, E)

And the results are: 0., 4.411954070, 2.423743792

The problem is with the second answer because it does not exist. If we plot the LHS and the RHS of eq1 vs E where E=0..5.4

plot([2*cot(0.76*sqrt(2*E)), (2*E-5.4)/sqrt(E*(5.4-E))], E=0..5.4, -3..3)

And it gets more interesting, if we calculate:

solve(evalf(eq1), E)

The answers are: 0., 2.423743793, 14.33807304+27.39159712*I

where the 3rd answer is again incorrect.

Finally, if a = 0.8 or larger, the incorrect answers disappear. 

Note - fsolve does handle this problem correctly. And despite my attempts to remind them to use fsolve, they see the solve command as the universal truth. Apparently this will be another teaching moment for next year.

So any thoughts about why this happens and why there is a difference in the outcomes between 0.76 and 0.8 for the value of a?

 

hi.

how i can dsolve this differential equations?

thanks

ich.mw
 

restart; Digits := 50; dsol1 := dsolve({diff(F(eta), eta, eta, eta)+.5*H(eta)*((diff(F(eta), eta))^2+F(eta)*(diff(F(eta), eta, eta)))/G(eta)^2+2*(diff(G(eta), eta))*(diff(F(eta), eta, eta))/G(eta)-(diff(H(eta), eta))*(diff(F(eta), eta, eta))/H(eta) = 0, diff(G(eta), eta, eta)+H(eta)*((diff(F(eta), eta))*G(eta)+.5*F(eta)*(diff(eta, eta)))/G(eta)^2+2*(diff(G(eta), eta))^2/G(eta)-((diff(H(eta), eta))*(diff(H(eta), eta)))/H(eta)+(diff(F(eta), eta, eta))^2-(H(eta)/G(eta))^2 = 0, diff(H(eta), eta, eta)+(.5*1.3)*H(eta)*(5*(diff(F(eta), eta))*H(eta)+F(eta)*(diff(H(eta), eta)))/G(eta)^2+2*(diff(G(eta), eta))*(diff(H(eta), eta))/G(eta)-(diff(H(eta), eta))^2/H(eta)+(1.3*1.44)*H(eta)*(diff(F(eta), eta, eta))/G(eta)-(1.3*1.92)*(H(eta)/G(eta))^3 = 0, F(0) = 0, G(0) = 0, H(0) = 0, (D(F))(0) = 1, (D(F))(1) = 0, (D(G))(0) = 0, (D(H))(0) = 0}, 'maxmesh' = 900, numeric, output = listprocedure, method = bvp[middefer], abserr = 0.1e-2); fy := eval(F(eta), dsol1)

Error, invalid input: eval received dsol1, which is not valid for its 2nd argument, eqns

 

 

NULL


 

Download ich.mw

 

I did not realize Maple 2016, since Maple 2015 actually, had stopped Windows XP support. 

When transfering a particular worksheet from my home Windows 7 computer to an office Linux computer I lose some of the end of the worksheet, namely I lose a rather memory intensive animation at the end. And the office compute crashes when I attempt to run the animation. This seems strange since apparently the office computer (see below) is more powerful than my home computer.  When this happens there are apparently few if any other users of the office computer. I  would be grateful for suggestions for remedies for this problem or any ideas of what the problem could be.

Home computer: Windows 7 Intel(R) Core(TM) i7-2600 CPU@3.40GHz, 12 GB RAM 64-bit OS

Office computer: CentOS, Kernel Linux 2.6.32-573.12.1.l6.x86.64, Gnome 2.28.2, Memory 94.4GiB, 6 processors each an Intel(R) Xeon(R) CPU E5-2643 v2@3.5BHz, Available Disk Space 1061.0 BiB

Hello, 

I loaded Maple to my friend's PC. But we can not execute any command in worksheet. When we write some lines and hit enter, it does not respond in anyway. (excluding simple calculations such as: 2+3 etc.) What is the problem and how can we solve it? 

PC: Windows 10 

Maple 2016.1

Hello all, 

A question concerning NetCdf files was asked in 2012 and is still unanswered today.
Browsing the questions only returns this item, suggesting the NetCdf topic is not a concern in the Maple community.
Nevertheless, does it exist some capabilities in reading and writting NetCDF files ?
If not, are there some planned development on the subject ?

Let's hope now for not having to wait four years for an answer, all responses will be greatly appreciated, even negative.

years


PS : NetCdf capabilities already exist in Sage or Mathematica

Can i make Explore with number of parameters differs from parameter in explore?
For excemple i whant to make sum with 'l' values wich will declorate in explore, and 'l' - count of them will declorate in same explore, but it dont work, so is it posible?
 

restart

``

``

Explore(add(cat('c', eval('i')), i = 1 .. l), parameters = [l = [seq(i, i = 1 .. 5)], seq(cat('c', eval('i')) = 0 .. 1.0, i = 1 .. l)])

Error, unable to execute seq

 

``

ec := proc (l) global f, p; f := add(cat('c', eval('i')), i = 1 .. l); print(f); p := [seq(cat('c', eval('i')) = 0 .. 1.0, i = 1 .. l)]; Explore(f, parameters = p) end proc;

proc (l) global f, p; f := add(cat('c', eval('i')), i = 1 .. l); print(f); p := [seq(cat('c', eval('i')) = 0 .. 1.0, i = 1 .. l)]; Explore(f, parameters = p) end proc

(1)

``

ec(4);

c1+c2+c3+c4

(2)

Explore(ec(l), l = [seq(i, i = 1 .. 5)])

c1

(3)

``

NULL


 

Download Explore_Problem_Exemple.mw

 

Dear Friends, I work with physics paсkage. I have a quation. I don't understend how one works with metrics. For example, let:

Nice!
Very good!

1) It doesn't work. Why? (I want exactly gamma_[A,B], rather than g_[A,B], because as i guess gamma_[A,B] has a signature [1,1,1] but g_[A,B] has a signature [-1,-1,-1])

 2) And how may I see what is matrices g_[A, B], gamma_[A, B] explicitly? That is I know how to see what is g_[mu, nu], for this one needs write "g_[];".  But how may I see g_[A, B] and gamma_[A, B] in explicitly forms?

3) Why command Trace(g_[mu, nu]))  does not work?"

HI

please help me for dsolve this nonlinear differential equations

thanls...

HAB.mw
 

restart; Digite := 100; Phi0 := 5; A := b*h; g13 := 31/250000000; g1 := 113/500000; f13 := 1/1000000000; c1 := 226000000000000; b := 10*10^(-9); J := (1/12)*b*h^3; h := 15*10^(-9); L := 100*10^(-9); E1 := (339/10000000000000000000000)*(diff(u(x), x, x, x, x))+(1017/10000000000000000000000)*(diff(w(x), x, x))*(diff(w(x), x, x, x))+(339/10000000000000000000000)*(diff(w(x), x, x, x, x))*(diff(w(x), x))-(339/10000)*(diff(u(x), x, x))-(339/10000)*(diff(w(x), x))*(diff(w(x), x, x)) = 0

E2 := -(1017/1600000000000000000000000000000000000000)*(diff(w(x), x, x, x, x, x, x))+(1589109/2500000000000000000000000)*(diff(w(x), x, x, x, x))-(339/10000*(diff(u(x), x, x)+(diff(w(x), x))*(diff(w(x), x, x))))*(diff(w(x), x))-(diff(w(x), x, x))*((339/10000)*(diff(u(x), x))+(339/20000)*(diff(w(x), x))^2+0.5824000000e-4)+(339/10000000000000000000000)*(diff(w(x), x, x))*(diff(u(x), x, x, x)+(diff(w(x), x, x))^2+(diff(w(x), x, x, x))*(diff(w(x), x)))+(339/10000000000000000000000)*(diff(w(x), x))*(diff(u(x), x, x, x, x)+3*(diff(w(x), x, x))*(diff(w(x), x, x, x))+(diff(w(x), x, x, x, x))*(diff(w(x), x)))-2 = 0:
 

E3 := -5.385803274*10^(-17)*(diff(Phi(x), x, x))+2.659881780*Phi(x)-5.125107476*10^(-20)*(diff(psi(x), x, x))+1.146681319*psi(x)+3.300000000*10^(-8)*(diff(w(x), x, x)) = 0:

E4 := -5.125107476*10^(-20)*(diff(Phi(x), x, x))+1.146681319*Phi(x)+(891/100000000000000)*(diff(psi(x), x, x))/Pi+34976.39822*psi(x)+0.4351500000e-5*(diff(w(x), x, x)) = 0:

dsys3 := {EQ1, EQ2, EQ3, EQ4, c1*J*((D@@2)(w))(0)+A*g13*((D@@2)(w))(0)-2*b*f13*Phi0-g1*J*((D@@4)(w))(0)+g1*A*(((D@@2)(u))(0)+((D@@1)(w))(0)*((D@@2)(w))(0))*((D@@1)(w))(0) = 0, c1*J*((D@@2)(w))(L)+A*g13*((D@@2)(w))(L)-2*b*f13*Phi0-g1*J*((D@@4)(w))(L)+g1*A*(((D@@2)(u))(L)+((D@@1)(w))(L)*((D@@2)(w))(L))*((D@@1)(w))(L) = 0, Phi(0) = 0, Phi(L) = 0, psi(0) = 0, psi(L) = 0, u(0) = 0, u(L) = 0, w(0) = 0, w(L) = 0, (D(u))(0) = 0, (D(u))(L) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(L) = 0}; dsolve(dsys3, numeric, initmesh = 3024, abserr = 0.1e-4)

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

 

``


 

Download HAB.mw

 

Hey, this is not the I've had this encounter. I want to open this saved document but when I open it and Maple starts up it just hits me with "A problem was encountered while opening the workbook. Database is not opened". How can I get to open it properly and see my math notes?

How can this be prevented?

When I try to upload the file in this message it says "Cant open a null file"

Any help?

 

Jacob

 

I am writing a package to define a few Records and collect some quantities and formulae to do some arithmetic with.

At some point I started running into a severe problem: Each time I want to use one of the exports form the module, the Maple kernel dies with a "Stack limit exceeded" message. The issue is: This seems to happen only on Maple 2016. I had some issues in Maple 2015 but that got sorted by rewriting some stuff. I never had any issue like that with Maple 15. I went as far as commenting out most of my .mapleinit code to make sure that did not cause issues. The code works as intended in Maple 15 and in Maple 2015.

I am posting this here and am asking others to see if they can reproduce this. Needless to say I will SCR this. But I actually need to get this to work.

The error can be triggered by simply entering

Booster;

after loading the package. Needless to say, it should just echo the name "Booster", to get more one would need to enter eval(Booster) (due to the last-name evaluation rules).

Thanks,

M.D.

BooMBA.mw

Dear all!.       

I have an expression with ramdom variables. Can i use NLP to optimize it?. In this case, does Maple take the histogram of theses ramdom variables?. Thank!!!

What is the difference between the Expression Palette and the Layout Palette? First I thought that the Layout Palette is supporting the entering of names with e.g. sub- and superscripts, but I learned (the hard way) that the templates of the Layout Palette are "mathematically active".

What is the meaning of the colours green and violett in both palettes?

Dear Community,

Would someone have a good and easy to understand/implement description of the Den Iseger algorithm for the numerical inversion of Laplace transform? Even better if someone would have a Maple script to do it, that would be superb.

Tx in advance,

best regards

Andras

I updated the OSX from El Capitan 10.11 to Sierra 10.12.

After then, whenever I try to input Japanese characters, Internal Error notification appears, and it crashes.
As it is not realistic to go back to the old OS, as the time when I did back up was a little before, I wouldn't do so.
Then, I might end up torelating not using Japanese until the next version of maple appears next year.
Are the situations like this ?

I know there might not be any response as this is about inputting Japanese characters.

Best wishes.

taro

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