Why nothing changes?

Could someone help me understand what is happening to this procedure. When I run it, I get the subject error. Thanks.

game := proc()
  local player1, player2, roll;
  roll := rand( 1..6 );
  player1 := roll():
  player2 := roll(2):
  if player1>player2 then "A wins"
  elif player1=player2 then "Tie"
  else "B wins"
  end if;
end proc:

Derive the orbit of the Moon around the Earth by doing a Verlet algorith of Molecular Dynamics simulation. Use one hour for your step τ. Place the stationary Earth at the origin of the Cartesian system. For initial conditions, use the position and the speed of the Moon when it is at its apogee (furthest from Earth). Plot the orbit.

Dear friends.

I need a simple approach for reading a specified line of a text file.

FileTools[Text] module allows to count the lines. By sequential reading of lines it's possible to reach any position in the file. But for large file this takes a lot of time.

FileTools[Position] allows to set/get position in the file, but the position is counted in bytes.

Are there any workarounds for the problem or the use of Database Package is more preferable?

Hello,

please help check what's wrong with this code. I need the analytic solution and convert to Bessel but return error. Here is the worksheet ID_1.mw

Best regards.

Hi,

this code not answer:

> whit*evalf; tx := evalf((t1+t2)*(1/2));
> t1 := 326*40; t2 := 327*40;
> y1, y2 := eval([y1, y2], Ns(t1), Ns(t2));
>while (t1 < tx) and (tx < t2) do:
yx := rhs(Ns(tx)[c2]):
if yx > 0 then
y2 := yx: t2 := tx:
else
y1 := yx: t1 := tx:
fi;
od;
>Tx = evalf(tx);
> Hx := floor((1/3600)*tx):
> Mx := floor((tx-3600*Hx)*(1/60)):
> Sx := tx-3600*Hx-60*Mx:
> Hx, Mx, Sx;
> XS := [seq(X[i], i = 0 .. 328)]: YS := [seq(Y[i], i = 0 .. 328)]:
> VxS := [seq(Vx[i], i = 0 .. 328)]: VyS := [seq(Vy[i], i = 0 .. 328)]:
> save(G,Mz,Xs,VxS,VyS, 'orbit.sav'):

 can you help me?

This might seem easy but i am a total beginner in Maple and i really need to know how to do this. If i have an expression like this:

X^2 + 3*y + 3*z + X^7

where (y) and (z) are constants of unknown values. I need to integrate the expression over an interval for example (from 1 to 10) so that the answer would still be in terms of (y) and (z).

Would anyone please help me and give me the right expression for writing this on Maple?

Thanks in advance.

(a) Show that if {an} ∞ n=1 is Cauchy then {a 2 n} ∞ n=1 is also Cauchy. (b) Give an example of a Cauchy sequence {a 2 n} ∞ n=1 such that {an} ∞ n=1 is not Cauchy

In case anyone is interested, we recently posted a new application on the Application Center,

Time Series Analysis: Forecasting Average Global Temperatures

While interesting in itself (well, I think so, anyway), this application also provides tips and techniques for analyzing time series data in Maple, and shows how to access online data sets through the new data sets functionality in Maple 2015.

eithne

Show that 2^3 + x ^2 − 3x + 2 is O(x ^3 ).

Hi EveryOne!

In the the answer of the question "How to find k^th root of the given matrix over finite field (at URL: http://www.mapleprimes.com/questions/203997-How-To-Find-Kth-Root-Of-The-Given-Matrix#comment215683). Carl Love helped to find k^th root of the given matrix M over GF(2^m)/f(x).

Now, I need to compute direct exponentiation of the given matrix M in finite field. (If M = [m_i,j], we say Direct Exponent (element-wise exponent matrix), M_d^k of M is a matrix whose each element is the result of exponentiation of corresponding elements of M. If k=2, then we say M_d² is a direct square matrix of M )

Please help me!!! Thank you very much.

I've seen a few maple presentations where a block of code is wrapped in a box. Does anyone know how this is done?

Hello, 

     I an trying to plot a function of a single variable, which is an implicit function of another variable, i.e. I want to plot F(x(t)), given that x and t are related through the implicit constraint equation f(x,t) = 0. Is there any plot stuctures in Maple that would easily let me do this? I tried implicit plot but this seems insufficient. 

     As an example, consider plotting F = x + x^2 subject to f = x + sin(x) + ln (t) = 0. I could also write this as  a function subject o a differential constraint, as is f = diff(x(t), t) + 1/t + (diff(x(t), t))*cos(x(t)) = 0 and try to use some sort of implicit DE plotting routine. 

     Any ideas?

Thanks!

I am running Maple in a windows virtual machine, on a mac computer.

I have a number of worksheets on its disk

Windows advised me to run its error checking utility (chkdsk)

when I try and open them it gives me a number of options:

maple text

plain text 

and maple input

None of these are the same as the original files. What has happened? and how can i fix it?

Hi all,

Thanks for helping me to solve the problem below using Maple.

dsys := {(1-4*(diff(ln(v(z)), z)))*(diff(u(z), z))+((3/2)*z^{-1}-2*(3* z^{-1} *(diff(ln(v(z)), z))+2*(diff(ln(v(z)),z,z )))))*u(z) = 0, -z*(diff(v(z), z))-v(z)+v(z)^(1/2)*u(z) = 0, v(0) = 1, u(0) = 1, (D(v))(0) = 1/4, (D(u))(0) = 3/8}

When trying    sol := dsolve(dsys, numeric)

I got : Error, (in DEtools/convertsys) unable to convert to an explicit first-order system.

Note that the analytic solution for z<=0 is:

if z>-4   then  u(z)=(1+z/4)exp(z/8) and   v(z)=exp(z/4)

else u(z)=0  and v(z)= (-4/z)exp(-1)

Regards