Hello Maple users,
Help me to find all positive real solutions of the polynomial containing a small parameter "c" as:

(solution must be in term of c).

Hello,  after almost a decade not using Maple, I am trying to get going to solve a set of differential equations and I have some problems that are probably pretty basic.

1.  I have the following simplification equations

which rightfully gives

and

which I hoped would give

but gives

"Error, invalid left hand side in assignment".  What am I doing wrong?

2.  The above simplification equations will be used to simplify this vector:

Once I get passed the "Invalid left hand side assignm,ent" issue, I would like to reorganize each line of the above vector and simplify using the small equations above.  What command do I need to use to do this?  The Phi & Beta variables are not necessarily next to one another so the equations need to be reorganized and the substitution for Omega & Omega_dot done.

Any help is appreciated! Thanks

Dear friends,

Download 3Dplot_given_Data_xyz.mw

Hi everibody 

I work with Maple 2015 under OS-X El Capitan.

Using more than one matrix vector product (either M.V  or MatrixVectorMultiply(M,V)  ; M is a n by p matrix and V a column vector of size p) within the same block of commands generates an error.

Do other people have the same problem ?
Thanks for your feedback.

SomethingGoesWrong.mw


PS : I know I can do this   X . <<1, 1, -1> | <-1, 2, 0>> but this doesn't explain the error I get

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 the answer:

In reality, it is the 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 many expressions in a worksheet like this:

latex(%, "equations.tex", append = true)

I should have defined a file name like this:

fname := "C:/home/MyStuff/Economics/MICRO NOTES/equations.tex"

And then replaced the first expression throughit the worksheet by:

latex(%, fname, append = true)

To acheive this I open the Find/Replace dialogue as in picture below:

This does not work. Instead of replacing with fname the result is "fname" .  Is there any way of doing what I want?

interface(prettyprint=0):
interface(screenwidth=500):
with(LinearAlgebra):

expect 

Matrix([[a1,a2,3],[5,6,7],[9,10,12]])

but

it print datatype = anything,storage = rectangular,order = Fortran_order,shape  and (2,1) etc

Matrix(3,3,{(2, 1) = 1, (3, 1) = 1, (3, 2) = 1},datatype = anything,storage = rectangular,order = Fortran_order,shape = []), 

what are the dynamical system which act on invariant manifold?

Hi,

Quick question.  If I was to solve a second order ODE using the dsolve function, and I was to use the numeric option such that I get a Procedure as the result.  Lets say I run something like sol:=dsolve(...,numeric);  If theta is the parameter to sol, then I can obviously call sol(Pi) to return the solution at Pi, I will receive the following result [theta=Pi, r(theta)=..., D(r)(theta)=...].

Now, lets say I wanted a Polarplot of [theta,r(theta)], how can I acheive this?

I have tried several ways, my thinking was something like polarplot(rhs(evalf(sol(theta))[2],theta=0..2*Pi); but I get the following "Error, invalid input: rhs received eqn_n(theta)[2], which is not valid for its 1st argument, expr".

Would anyone of you clever people have any pointers on how to polarplot a numeric solution?

Thankyou.

Hi!

I'm doing an assignment where we are supposed to create a random walk with 3 options (go straight forward, turn left, turn right), and the first step is to be taken to [1,0]. I am supposed to plot the result afterwards, but when I plot it, it's empty...

(The first # is forward, the second # is to the right, and the third # is to the left)

for i to M0 do

X[i, 0] := 1; Y[i, 0] := 0;

for j from 2 to M1 do

r := R3();

if r = 1 then X[i, j] := 2*X[i-1, j]-X[i-2, j]; Y[i, j] := 2*Y[i-1, j]-Y[i-2, j];

elif r = 2 then X[i, j] := X[i-1, j]+Y[i-1, j]-Y[i-2, j]; Y[i, j] := Y[i-1, j]-X[i-1, j]+X[1-2, j];

else X[i, j] := X[i-1, j]-Y[i-1, j]+Y[i-2, j]; Y[i, j] := Y[i-1, j]+X[i-1, j]-X[i-2, j];

end if;

end do;

end do:

Then, for the plot:

plot([[[([X[i, j], Y[i, j]], $j = 0 .. M1)], $i = 1 .. M0)], scaling = CONSTRAINED);

This is what I got for the plot:

Where have I gone wrong? 

Thanks in advance!

Hello everybody, 

I used Maple to reach a function in terms of a few parameters. The issue that I'm facing is that when I copy and paste that equation to excel(after transforming that same equation to 1D math) for evaluating it's value with the real values for the parameters, the result is not the same as the one calculated by Maple 2016 with the exact same parameters. I've inserted the file with this question for further information. One of the parameters (F15) is the cell used in excel.

equation.mw

Download equation.mw

Any help regarding this problem is very much appreciated.

I have tried

assume(n >= 0, n::integer);

But still,

simplify(exp(-n*ln(2*Pi)))

does nothing.

I want to convert it to (2*Pi)^(-n).

Hi,

I am doing Principal Component Analysis (PCA) and I think the Biplot procedure could be improved.

When you use PCA is common to look what happens in other planes than the plane defined by the first two eigenvectors.
Unfortunately Biplot deals only with 2D projections onto this first plane and with 3D projections onto the space spanend but the first three eigenvectors.

I modified slightly the original Biplot procedure for it to handle different 2D and 3D projections planes.
The code is given in the attached mw file (original commands are written red over yellow and the new ones yellof over red).

I'm not at all certain mapleprimes/questions is the best place to post ???


Biplot.mw

Hi,

This sequence of commands works perfectly well

     plotsetup(jpeg, plotoutput=SomeJpegFile);
     plot(x, x=0..1);
     plotsetup(default);


Why this one doesn't create the file SomeJpegFile ?

f := proc()
     plotsetup(jpeg, plotoutput=SomeJpegFile);
     plot(x, x=0..1);
     plotsetup(default);
end proc;

f();


Thanks in advance

Maple gives the integral's face instead of giving a number as the numerical integration, no matter what command for the numerical integration I use. Does any one know what the problem is?

T2start := -5.036645000*10^9*(x[5]^2+.2725890432*x[5]+.3732640349)*x[5]/(5.036645000*10^9*x[5]^2+1.27004241*10^8*x[5]+5.3714241*10^7); 
T2end := -5.036645000*10^9*(x[5]^2+.2871403962*x[5]+.3945934083)*x[5]/(5.036645000*10^9*x[5]^2+1.27004241*10^8*x[5]+5.3714241*10^7);
J := (25183225000000*x[5]^4+(-100732900000000*T[2]+73827142410000)*x[5]^3+(-112645777230000*T[2]+662242877289)*x[5]^2-2398770574578*T[2]*x[5]-393671672289*T[2])/(10000000*x[5]^2+14658000*x[5]);
int(abs(J), [T[2] = T2start .. T2end, x[5] = 0 .. infinity], numeric);

I also used the following.

evalf(Int(abs(J), [T[2] = T2start .. T2end, x[5] = 0 .. infinity]));

The result was same.

Or when I use

evalf(Int(abs(J), [T[2] = T2start .. T2end, x[5] = 0 .. infinity], method = _MonteCarlo));

It gives an error saying:

Error, (in evalf/int) invalid arguments