Hi,

I started using Maple recently. The output sometime is not simplified like that in the attached picture. How can I simplify such expressions?

http://www.maplesoft.com/applications/view.aspx?SID=1526&view=html

near the middle, it says

I just tried in Maple 2016 and that is not what it did. It says this was in Maple 8. It seems this was "fixed" in Maple 2015.

My question: How could Maple 8 have simplified rand()/rand() to 1 before evaluating rand()?  i.e. why was not rand() evaluated first, before the simplification was made? it seems to have worked as if one typed x/x , but rand() would have been a function, and it should be evaluated before?

Just wondering why Maple 8 did the above, that is all.

How to view the source code for a created .mv file in Maple?

 helo my friends,

i try to do this code, please help me to understant what is the problem

I am tying to compute the wronskian of a fourth order DE: y=C₁e^2x+ C₂e^-x +C₃xe^-x+ C₄x²e^-x Here's what I did:

with(VectorCalculus):
with(LinearAlgebra):

Determinant(Wronskian([e^(2*x), e^(-x), xe^(-x), x^2*e^(-x)], x)):

which gave nothing.
Can anyone please help?

Thanks in advance,

AJ

newbie here. When I give Maple 2016.2  a boundary value ODE with an eigenvalue in it, it returns the trivial solution. I was wondering if Maple supports finding non-trivial solution and also give the eigenvalue values associated with the non-trivial solution?

restart;
ode:=diff(y(x),x$2)+lambda*y(x)=0;
bc:=y(0)=0,y(L)=0:
assume(L>0,L,'real'):
sol:=dsolve({ode,bc},y(x));

The outtput is `y(x)=0`

In Mathematica, it gives both trivial and non-trivial solution:

Clear[L0, lam, x, y, r]
ode = y''[x] + lam y[x] == 0;
bc = {y[0] == 0, y[L0] == 0};
sol = Assuming[Element[L0, Reals] && L0 > 0, 
  DSolveValue[{ode, bc}, y[x], x]]

And the answer is

If Maple does not currently support this, any one knows if this will added to Maple 2017?

Hi, there!

I try to simplify the next expression:

Simplify(LeviCivita[4, sigma, lambda, rho]*LeviCivita[4, xi, eta, mu]*g_[rho, mu]*qp[sigma]*q[lambda]*qp[xi]*q[eta])

Maple gives answer:

In reality it is incorrect answer, because indices must run over 1,2,3 but not 1,2,3,4!

SumOverRepeatedIndices(%) confirms that maple mistakes.

my preamble is:

with(Physics)

Setup(mathematicalnotation = true);
Coordinates(X);

Setup(spaceindices = lowercaselatin)

Setup(tensors = q[mu](X))

PDEtools:-declare(q(X))

Setup(tensors = qp[mu](X))

PDEtools:-declare(qp(X))

I have a derivative distribution function f that is defined:

f:=piecewise(x < .114e-1,0.,x < .129e-1,0.,x < .147e-1,0.,x < .167e-1,0.,x < .189e-1,0.,x < .215e-1,0.,x < .244e-1,0.,x < .278e-1,0.,x < .315e-1,0.,x < .358e-1,0.,x < .407e-1,0.,x < .463e-1,0.,x < .526e-1,0.,x < .597e-1,0.,x < .679e-1,0.,x < .771e-1,0.,x < .876e-1,0.,x < .995e-1,0.,x < .113,0.,x < .128,0.,x < .146,0.,x < .166,0.,x < .188,0.,x < .214,0.,x < .243,0.,x < .276,0.,x < .314,0.,x < .357,0.,x < .405,0.,x < .46,0.,x < .523,0.,x < .594,0.,x < .675,-.8800000000+1.481481481*x,x < .767,-.3935869565+.7608695652*x,x < .872,-.3213333333+.6666666667*x,x < .991,-.2529411765+.5882352941*x,x < 1.13,-.1690647482+.5035971223*x,x < 1.28,-.2026666667+.5333333333*x,x < 1.45,-.1223529412+.4705882353*x,x < 1.65,-.1650000000+.5000000000*x,x < 1.88,-.2726086957+.5652173913*x,x < 2.13,-.5636000000+.7200000000*x,x < 2.42,-.8662068966+.8620689655*x,x < 2.75,-1.200000000+1.000000000*x,x < 3.12,-1.645945946+1.162162162*x,x < 3.55,-1.865581395+1.232558140*x,x < 4.03,-2.075416667+1.291666667*x,x < 4.58,-1.925818182+1.254545455*x,x < 5.21,-1.559682540+1.174603175*x,x < 5.92,-.7967605634+1.028169014*x,x < 6.72,.3320000000+.8375000000*x,x < 7.64,1.942608696+.5978260870*x,x < 8.68,3.791923077+.3557692308*x,x < 9.86,5.850169492+.1186440678*x,x < 11.2,7.902985075-.8955223881e-1*x,x < 12.7,9.737333333-.2533333333*x,x < 14.5,10.82388889-.3388888889*x,x < 16.4,11.78631579-.4052631579*x,x < 18.7,11.34347826-.3782608696*x,x < 21.2,10.85240000-.3520000000*x,x < 24.1,9.311379310-.2793103448*x,x < 27.4,7.619090909-.2090909091*x,x < 31.1,5.814864865-.1432432432*x,x < 35.3,4.025714286-.8571428571e-1*x,x < 40.1,2.544375000-.4375000000e-1*x,x < 45.6,1.519090909-.1818181818e-1*x,x < 51.8,.8370967742-.3225806452e-2*x,x < 58.9,.6700000000,x < 66.9,.5963750000+.1250000000e-2*x,x < 76,.9005494505-.3296703297e-2*x,x < 86.4,1.161538462-.6730769231e-2*x,x < 98.1,1.318461538-.8547008547e-2*x,x < 111,1.544651163-.1085271318e-1*x,x < 127,1.241875000-.8125000000e-2*x,x < 144,1.106470588-.7058823529e-2*x,x < 163,.7721052632-.4736842105e-2*x,x < 186,0,x < 211,0,x < 240,0,x < 272,0,x < 310,0,x < 352,0,x < 400,0,x < 454,0,x < 516,0,x < 586,0,x < 666,0,x < 756,0,x < 859,0,x < 976,0,x < 1110,0,x < 1260,0,x < 1430,0,x < 1630,0,x < 1850,0,x < 2100,0,x < 2390,0,x < 2710,0,0):

I want to do a simple numerical integration of that function - that means I have k points of independent variable x and together with dependent variable points it looks like:

I was trying to resolve this in Maple:

f_list:=convert(f,list):

integralbodyx:=[seq(0+((200-0)/100)*i,i=1..100)]:

integralbodyy:=[seq(sum((eval(f_list[0+((200-0)/100)*j],x=(0+((200-0)/100)*j)))*2,j=1..i),i=1..100)]:

but I get an error 

Error, (in limit/mrv/limsimpl) too many levels of recursion

Can you help me with the syntax? Thank you.
 

Dears 

Hope you would be fine. I want to solve the following PDEs by numerically for v[nf]=alpha[nf]=Ec=mu[nf]=C=1 and Pr=6.2

Eq1 := diff(u(x, t), t) = v[nf]*(diff(u(x, t), x, x));

Eq2 := diff(u(x, t), t) = alpha[nf]*(diff(theta(x, t), x, x))/Pr+Ec*mu[nf]*C*(diff(u(x, t), x))^2;

ICs := u(x, 0) = 0, theta(x, 0);

BCs := u(0, t) = 1, theta(0, t) = 1, u(10, t) = 0, theta(10, t) = 0;

and find the values of (diff(u(0, t), x))/(1-phi)^2.5 for different values of phi. Thanks in advace 

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Please can someone help me with looping involving 4 variables such as S₁ S₂ S₃ S₄ from a series

S_n+1 =f(f-a)+u+V_n+w

V_n+1 =wc+f a-A_n+ u  if A_n = U_n+V_n

I use Ubuntu 14.04 and X, not the desktop.  I use emacs/maple 2016.

GNU Emacs 25.1.2 (x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2017-03-1

;;; maplev.el --- Maple mode for GNU Emacs

;; Authors:    Joseph S. Riel <joer@k-online.com>
;;             and Roland Winkler <Roland.Winkler@physik.uni-erlangen.de>
;; Time-stamp: "2003-10-09 22:49:16 joe"
;; Created:    June 1999
;; Version:    2.155
;; Keywords:   Maple, languages
;; X-URL:      http://www.k-online.com/~joer/maplev/maplev.html
;; X-RCS:      $Id: maplev.el,v 1.14 2006-06-02 14:02:38 joe Exp $

I use emacs/maple mode with maple 2016.  Quite often, emacs looses connection with the maple server.  I do  not remember this happening or maybe not as often, with earlier versions of maple.

After using maple/emacs, I started xmaple.  After a few expression evaluations, the maple server stopped.  Restarting xmaple and repeating the expression evaluations many times, I do not get the crash.  So, this appears to be a difficulty with external connections to the maple server.

Does a later version of maple mode exist?

I expected plot with an undefined name to do nothing, but,

plot(asdf);

actually plots y=x!

How to create a hyperplane which perpendicular to groebner basis

Hello,

I am trying to write a procedure to see, which (di)-graphs are isomorphic (here represented by there 3*3 adjecency-matrices). When I try the procedure for all 3*3-matrices with entries in {0,1} (there are 512 of them), I get the following error:
"Error, (in GraphTheory:-IsIsomorphic) invalid subscript selector"

Can you possibly say, what I am doing wrong? My code is the following:

My input is a list (JJ) of 512 3*3 matrices constructed the following way :

When I run this procedure on some of the 512 matrices it does work, but it crashes somewhere around matrix 350. I have try so split the list of the 512 matrices, and I am able to run the procedure on these splits, but this is very inconvenient :-)

I hope you can help me. Also if this can be done in an easier way - I am new to programming and recieve help with a smile.

Yours, Tomas.