How long will MAPLE 16 and future versions of MAPLE will support running on Windows 7? 

MRB

(I hope to defer transferring to Windows 10 until MS stop supporting for Windows 7.)

Hello,

I am unable to use subs() command when using subscript : I'd like to replace YP__1 with dGx in the equation :

"Eq:= YP__1 = Y__2" (Eq:= YP₁=Y₂)

 so I have tried : subs({YP__1=dGx},Eq)

But it doesn't work... It give me : YP__1 = Y__2 and I would like to have dGx = Y__2

I have tried also with subs({YP[1]=dGx},Eq) but doesn't work too.

If I am not using subscript, for exemple : Eq:= YP1 = Y2

And do : subs({YP1=dGx},Eq)

That works great...

But I must use subscript __ because Eq is a result from ODEtools (convertsys).

Can you help me please ?

Thanks you very much.

Regards.

Consider the list [x,y,z], say. Does there in Maple exist some fundamental function for querying the position in the list of x,y, and z, respectively? I am unable to locate any such. Such a function can, of course, be constructed, an example being the following:

listPos := (l::list) -> table(zip(`=`,l,[$(1..nops(l))])):
pos := listPos([x,y,z]);
pos[x],
pos[y],
pos[z];

But that seems unsatisfactory. The same question concerning Vectors: Consider Vector([x,y,z]), say. Here, the following code, say, will perform the task:

VectorPos := (V::Vector) -> table([map(rhs = lhs,op(2,V))[]]):
pos := VectorPos(Vector([x,y,z]));
pos[x],
pos[y],
pos[z];

PS: Of course, list and Vectors can be converted into one another, so any one of the codes above can in practice be used to perform both tasks.

The following code is part of my attempt to answer the recent Question about the bifurcation of the map f:= x-> exp(x^2*(a-x)). Two very weird things are happening. They can be seen by applying trace to f. The first is that the input argument to f seems to be changed to a very large integer. The second is that for some real values of a and x, I get imaginary results from this obviously real-valued function. Why are these things happening?

Download bifurcation.mw

How to show what class of bifurcation is in this function :   exp(x²*(a-x)) ?

I have a long list of two element lists, for example,

A := [ [2,3], [4,5] ,[6,7]];

I want apply '/' to the elements of each sublist.

The result will be

R := [2/3, 4/5, 6/7];

I do not need the list, I could use vectors or matrices.

Is it possible to do this other than by iteration?

Tom Dean

I want to set up a couple of tables. One problem I have is setting up the list of names for the columns.  u0 etc are actual variables. Being trying to use  ` ` and ' ' to stop them evaluating. I have even more problems with  h₆ as a name and symbols Sigma etc.

How do you do this so it looks neat and the name preferably doesn`t display the  ` ` or " " or '  '?

Download Table_Headers.mw

greatings all,

I want to calculate energy momentum tensor for a given metric. is it possible to calculate it in the physics package?
thanks.

Hi

Please find the attached file

The command PolynomialInterpolation doesn't work, I will be appreciate if you can help me

Thanks

Question.mw

hi.i am a problem for solving this non linear algebric equation.

please help me...thanks

FSOLVE.mw

FSOLVE.mw

With the RationalFunctionTutor generated then modified code (see egn2.mw attached).  Is it possible to make linestyle=spacedash for the two vertical asymtotes?  By selecting the graph and choosing from the plot menu the linestyle can be changed, but is there a way to do this with commands in the program code? 

egn2.mw

When I was editing the head of the question (? instead of .), its body disappeared. Please, insert it again.

Regard,

Markiyan Hirnyk

Maple 15.

I have a set of equations I can solve manually, but, solve fails.

restart;
eq1 := tgtX[1] = 0;
eq2 := tgtY[2] - y[2]    = m[2]*(tgtX[2]-x[2]);
eq3 := tgtY[3] - y[3]    = m[3]*(tgtX[3]-x[3]);
eq4 := tgtY[4] - y[4]    = m[4]*(tgtX[4]-x[4]);
eq5 := tgtY[2] - tgtY[1] = vy*t[2];
eq6 := tgtY[3] - tgtY[1] = vy*t[3];
eq7 := tgtY[4] - tgtY[1] = vy*t[4];
eq8 := tgtX[2]           = vx*t[2];
eq9 := tgtX[3]           = vx*t[3];
eq10:= tgtX[4]           = vx*t[4];
#
# solve the equations
eqs  := {eq1,eq2,eq3,eq4,eq5,eq6,eq7,eq8,eq9,eq10};

solvx := solve(eq10,vx);
solvy := solve(eq7,vy);
sol1  := subs(vx=solvx,{eq8,eq9});
sol2  := subs(vy=solvy,{eq5,eq6});

soln  := subs(sol1,{eq2,eq3});

soln  := subs(tgtY[2]=solve(sol2[1],tgtY[2]),soln);
soln  := subs(tgtY[3]=solve(sol2[2],tgtY[3]),soln);
soln  := subs(tgtY[1]=solve(soln[1],tgtY[1]),soln[2]);
soln  := solve({eq4,soln},{tgtX[4],tgtY[4]});

# this returns empty solution
solve(eqs,{tgtX[4],tgtY[4]});

Any ideas?

Tom Dean

Hello,

Is there an option/ or a way so as to ask pointplots to plot a interpolated curve for the points defined ?

Thank you for you help.

Hello,

I have a complex set of non linear diff eqns in the form :

y1'' = f(y1',y1,y2'',y2',y2,y3'',y3',y3,y4'',....,y6'',y6',y6,u1,u2,u3,u4) ;

y2'' = f(y1'',y1',y1,y2',y2,y3'',y3',y3,y4'',....,y6'',y6',y6,u1,u2,u3,u4)

and so on ... y6''=(...)

As I want to resolve this coupled systeme in matlab using @ODE45... I wanted the equations in the form : y1''=f(y1',y1,y2',y2,....) and so on ... => X'[] = f(X[],U[])

How can I force maple to rearrange a system of coupled eqns with only the variables i want ?

I know this is possible beacause it is a nonlinear state space model but maple do not work with nonlinear state space model... It give me error when I tried to create statespace model with my non linear diff eqns.

Thanks a lot !