Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I attempted to use convolution in AudioTools to convolve 2 vectors with arbitrary values, but could not since the operation is expecting numeric values.  Can this be done?    Is there not a convolution operastor in the LinearAlgebra package?  See attached:

convolutionWithAu[1].mw

I am new to Maple.

If i have a list (or a table) A:=[[1,2],[3,4],[5,6]

how can i split it into two lists B:=[1,3,5] and C:=[2,4,6] ? (all the 1st numbers in one list, and all 2nd numbers in another list).

Hello guys

Before starting, i must tell you that english is not my mother tongue, so sorry for my spelling errors :)

 

I have a work to do that ask me to solve the equation : e^((x))-x-5 with the Fixed Point Iteration method. (starting value=2 ; shutoff parameter = 10^(-8) and maximum number of iterations = 100).

I already try and at this time, I did that :

http://imgur.com/PGvmusk

But it doesn't seem to work. 

I am not very good with Maple...

I need some help :)

Thanks !

I'm trying to plot the lines that are based on eigenvectors of the matrix. (Functions r1(t),r2(t), q(t) are defined earlier. I can upload file if necessary)

with(LinearAlgebra):
x1:=t->-r1(t)*cos(Pi/2-q(t)/2):
y1:=t->-r1(t)*sin(Pi/2-q(t)/2):
z1:=t->0:
x2:=t->r2(t)*cos(Pi/2-q(t)/2):
y2:=t->-r2(t)*sin(Pi/2-q(t)/2):
z2:=t->0:
Ixx:=t->m*(y1(t)^2+z1(t)^2)+m*(y2(t)^2+z2(t)^2):
Iyy:=t->m*(x1(t)^2+z1(t)^2)+m*(x2(t)^2+z2(t)^2):
Izz:=t->m*(x1(t)^2+y1(t)^2)+m*(x2(t)^2+y2(t)^2):
Ixy:=t->-m*x1(t)*y1(t)-m*x2(t)*y2(t):
Ixz:=t->-m*x1(t)*z1(t)-m*x2(t)*z2(t):
Iyz:=t->-m*y1(t)*z1(t)-m*y2(t)*z2(t):

InertiaTensor:=t-><<Ixx(t),Ixy(t),Ixz(t)>|<Ixy(t),Iyy(t),Iyz(t)>|<Ixz(t),Iyz(t),Izz(t)>>:

 Here I define the matrix as a function of time. 

EV:=t->Eigenvectors(InertiaTensor(t));
V1:=t->Column(Re(EV(t)[2]),1);
V2:=t->Column(Re(EV(t)[2]),2);

Producing two eigenvectors also as functions of time.

InertiaAxis1 := t->plot(x, V1(t)[2]*x/V1(t)[1], x = -2 .. 2);
InertiaAxis2 := t->plot(x, V2(t)[2]*x/V2(t)[1], x = -2 .. 2);

InertiaAxis1(1);

And here I've got an error:

Error, (in plot) unexpected options: [-HFloat(7.378655652881484e-6)*x, x = -2 .. 2]

I tried to set "datatype=float"-option in plot function, to evaluate the coefficient by eval-function, it wouldn't help. What does this error mean exactly? 

I can not find a solution to the integral of the function below the maple, can anyone help me?

 

restart;
with(Student[MultivariateCalculus]);
with(Student[Calculus1]);

assume(-1 < rho and rho < 1, alpha1 > 0, beta1 > 0, alpha2 > 0, beta2 > 0, t1 > 0, t2 > 0)

f := proc (t1, t2, alpha1, beta1, alpha2, beta2, rho) options operator, arrow; (1/4)*(sqrt(beta1/t1)+(beta1/t1)^(3/2))*(sqrt(beta2/t2)+(beta2/t2)^(3/2))*exp(-((sqrt(t1/beta1)-sqrt(beta1/t1))^2/alpha1^2+(sqrt(t2/beta2)-sqrt(beta2/t2))^2/alpha2^2-2*rho*(sqrt(t1/beta1)-sqrt(beta1/t1))*(sqrt(t2/beta2)-sqrt(beta2/t2))/(alpha1*alpha2))/(2-2*rho^2))/(alpha1*beta1*alpha2*beta2*Pi*sqrt(1-rho^2)) end proc

int(int(f(t1, t2, alpha1, beta1, alpha2, beta2, rho), t2 = 1 .. infinity), t1 = 0.1e-2 .. y)

 

I run into a problem that really suprised me. I have a program that solves a system of differential equations with different initial conditions. I wrote a cycle that goes through initial conditions, solves differential equations and saves the picture (displaying dynamic behaviour of the system) in the given directory. All seemed fine and working until I once checked one of the pictures by running the program on the only one initial condition. It turned out that the picture program gave me this time is not the one that program gave me earlier (while running through cycle). So I panicked and started checking other pictures and it turned out that some of them are right and some of them are not, remarkably, with no particular pattern.

I reckon that I somehow need to manage the memory, clear it after every iteration. (I'm not absolutely sure that problem is here but I just don't have another explanation why this thing could happen.)

File:ClassicalTrajectoriesH2X_morse_pictures.mw

Quite often when i use maple I generate expressions that are of vast length, that with a pen and paper can be reduced in length by carefully factorizing, multiplying out and dividing through.

I am wondering if i am missig somethig- if this is a problem all maple users deal with, or if its just a limitation of the program.

Today, maple generated:

d*B[2211](t)/dt = 2*k[a2]*beta*k[d2]*B[2211]*(alpha*beta*R[b]*k[a1]^2+alpha*beta*R[b]*k[a1]*k[a2]+2*alpha*R[b]*k[a1]*k[d1]+2*alpha*R[b]*k[a1]*k[d2]+alpha*R[b]*k[a2]*k[d1]+alpha*R[b]*k[a2]*k[d2]+beta*k[a1]*k[d1]+beta*k[a1]*k[d2]+k[d1]^2+3*k[d1]*k[d2]+2*k[d2]^2)
/(alpha*beta^2*R[b]*k[a1]^2*k[a2]+alpha*beta^2*R[b]*k[a1]*k[a2]^2+alpha*beta*R[b]*k[a1]^2*k[d1]+alpha*beta*R[b]*k[a1]^2*k[d2]+3*alpha*beta*R[b]*k[a1]*k[a2]*k[d1]+3*alpha*beta*R[b]*k[a1]*k[a2]*k[d2]+alpha*beta*R[b]*k[a2]^2*k[d1]+alpha*beta*R[b]*k[a2]^2*k[d2]+alpha*R[b]*k[a1]*k[d1]^2+3*alpha*R[b]*k[a1]*k[d1]*k[d2]+2*alpha*R[b]*k[a1]*k[d2]^2+2*alpha*R[b]*k[a2]*k[d1]^2+3*alpha*R[b]*k[a2]*k[d1]*k[d2]+alpha*R[b]*k[a2]*k[d2]^2+beta^2*k[a1]*k[a2]*k[d1]+beta^2*k[a1]*k[a2]*k[d2]+2*beta*k[a1]*k[d1]^2+3*beta*k[a1]*k[d1]*k[d2]+beta*k[a1]*k[d2]^2+beta*k[a2]*k[d1]^2+3*beta*k[a2]*k[d1]*k[d2]+2*beta*k[a2]*k[d2]^2+2*k[d1]^3+7*k[d1]^2*k[d2]+7*k[d1]*k[d2]^2+2*k[d2]^3)
+(-2*k[d1]-2*k[d2])*B[2211]
+2*k[d1]*B[2211]*(alpha*beta*R[b]*k[a1]*k[a2]+alpha*beta*R[b]*k[a2]^2+alpha*R[b]*k[a1]*k[d1]+alpha*R[b]*k[a1]*k[d2]+2*alpha*R[b]*k[a2]*k[d1]+2*alpha*R[b]*k[a2]*k[d2]+beta*k[a2]*k[d1]+beta*k[a2]*k[d2]+2*k[d1]^2+3*k[d1]*k[d2]+k[d2]^2)*k[a1]*beta
/(alpha*beta^2*R[b]*k[a1]^2*k[a2]+alpha*beta^2*R[b]*k[a1]*k[a2]^2+alpha*beta*R[b]*k[a1]^2*k[d1]+alpha*beta*R[b]*k[a1]^2*k[d2]+3*alpha*beta*R[b]*k[a1]*k[a2]*k[d1]+3*alpha*beta*R[b]*k[a1]*k[a2]*k[d2]+alpha*beta*R[b]*k[a2]^2*k[d1]+alpha*beta*R[b]*k[a2]^2*k[d2]+alpha*R[b]*k[a1]*k[d1]^2+3*alpha*R[b]*k[a1]*k[d1]*k[d2]+2*alpha*R[b]*k[a1]*k[d2]^2+2*alpha*R[b]*k[a2]*k[d1]^2+3*alpha*R[b]*k[a2]*k[d1]*k[d2]+alpha*R[b]*k[a2]*k[d2]^2+beta^2*k[a1]*k[a2]*k[d1]+beta^2*k[a1]*k[a2]*k[d2]+2*beta*k[a1]*k[d1]^2+3*beta*k[a1]*k[d1]*k[d2]+beta*k[a1]*k[d2]^2+beta*k[a2]*k[d1]^2+3*beta*k[a2]*k[d1]*k[d2]+2*beta*k[a2]*k[d2]^2+2*k[d1]^3+7*k[d1]^2*k[d2]+7*k[d1]*k[d2]^2+2*k[d2]^3)

quite clearly there are expressions in there that can be factorised by (k[a1]+k[a2]) and the two quotients have the same denominator. Is there any way of minimizing the length of this expression by factorizing where appropriate, merging denominators when appropriate etc?

I am interested in the behaviour of a system of equations close to the origin- these equations are quite long, and there are a lot of them so i would like to have commands that i can use to assume products of variables are zero. 

here are the first two polynomials:


alpha*k[a1]*B[1]^2+(-alpha*k[a1]-alpha*k[a2])*B[2]*B[1]+2*alpha*k[a1]*B[1]*B[11]+alpha*k[a1]*B[12]*B[1]+2*alpha*k[a1]*B[1]*B[211]+alpha*k[a1]*B[221]*B[1]+2*alpha*k[a1]*B[1]*B[2211]+(-alpha*R[b]*k[a1]-k[d1])*B[1]+2*B[11]*k[d1]+B[12]*k[d2]+k[d1]*B[211]+k[d2]*B[221]

(-alpha*k[a1]-alpha*k[a2])*B[2]*B[1]+alpha*k[a2]*B[2]^2+2*alpha*k[a2]*B[2]*B[22]+alpha*B[2]*B[12]*k[a2]+alpha*k[a2]*B[2]*B[211]+2*alpha*k[a2]*B[2]*B[221]+2*alpha*k[a2]*B[2]*B[2211]+(-alpha*R[b]*k[a2]-k[d2])*B[2]+B[12]*k[d1]+2*B[22]*k[d2]+k[d1]*B[211]+k[d2]*B[221]

the varables are the terms with B and a subsript and everything else is a parameter.

My intuition was to use coeffs but I couldn't get anything helpful

The material below was presented in the "Semantic Representation of Mathematical Knowledge Workshop", February 3-5, 2016 at the Fields Institute, University of Toronto. It shows the approach I used for “digitizing mathematical knowledge" regarding Differential Equations, Special Functions and Solutions to Einstein's equations. While for these areas using databases of information helps (for example textbooks frequently contain these sort of databases), these are areas that, at the same time, are very suitable for using algorithmic mathematical approaches, that result in much richer mathematics than what can be hard-coded into a database. The material also focuses on an interesting cherry-picked collection of Maple functionality, that I think is beautiful, not well know, and seldom focused inter-related as here.

 

 

Digitizing of special functions,

differential equations,

and solutions to Einstein’s equations

within a computer algebra system

 

Edgardo S. Cheb-Terrab

Physics, Differential Equations and Mathematical Functions, Maplesoft

Editor, Computer Physics Communications

 

 

Digitizing (old paradigm)

 

• 

Big amounts of knowledge available to everybody in local machines or through the internet

• 

Take advantage of basic computer functionality, like searching and editing

 

 

Digitizing (new paradigm)

• 

By digitizing mathematical knowledge inside appropriate computational contexts that understand about the topics, one can use the digitized knowledge to automatically generate more and higher level knowledge

 

 

Challenges


1) how to identify, test and organize the key blocks of information,

 

2) how to access it: the interface,

 

3) how to mathematically process it to automatically obtain more information on demand

 

 

 

 

                                           Three examples


Mathematical Functions

 

"Mathematical functions, are defined by algebraic expressions. So consider algebraic expressions in general ..."

The FunctionAdvisor (basic)

 

"Supporting information on definitions, identities, possible simplifications, integral forms, different types of series expansions, and mathematical properties in general"

Examples

   

General description

   

References

   

 

Differential equation representation for generic nonlinear algebraic expressions - their use

 

"Compute differential polynomial forms for arbitrary systems of non-polynomial equations ..."

The Differential Equations representing arbitrary algebraic expresssions

   

Deriving knowledge: ODE solving methods

   

Extending the mathematical language to include the inverse functions

   

Solving non-polynomial algebraic equations by solving polynomial differential equations

   

References

   

 

Branch Cuts of algebraic expressions

 

"Algebraically compute, and visualize, the branch cuts of arbitrary mathematical expressions"

Examples

   

References

   

 

Algebraic expresssions in terms of specified functions

 

"A conversion network for arbitrary mathematical expressions, to rewrite them in terms of different functions in flexible ways"

Examples

   

General description

   

References

   

 

Symbolic differentiation of algebraic expressions

 

"Perform symbolic differentiation by combining different algebraic techniques, including functions of symbolic sequences and Faà di Bruno's formula"

Examples

   

References

   

 

Ordinary Differential Equations

 

"Beyond the concept of a database, classify an arbitrary ODE and suggest solution methods for it"

General description

   

Examples

   

References

   

 

Exact Solutions to Einstein's equations

 

 

Lambda*g[mu, nu]+G[mu, nu] = 8*Pi*T[mu, nu]

 

"The authors of "Exact solutions toEinstein's equations" reviewed more than 4,000 papers containing solutions to Einstein’s equations in the general relativity literature, organized the whole material into chapters according to the physical properties of these solutions. These solutions are key in the area of general relativity, are now all digitized and become alive in a worksheet"


The ability to search the database according to the physical properties of the solutions, their classification, or just by parts of keywords (old paradigm) changes the game.

More important, within a computer algebra system this knowledge becomes alive (new paradigm).

• 

The solutions are turned active by a simple call to one commend, called the g_  spacetime metric.

• 

Everything else gets automatically derived and set on the fly ( Christoffel symbols  , Ricci  and Riemann  tensors orthonormal and null tetrads , etc.)

• 

Almost all of the mathematical operations one can perform on these solutions are implemented as commands in the Physics  and DifferentialGeometry  packages.

• 

All the mathematics within the Maple library are instantly ready to work with these solutions and derived mathematical objects.

 

Finally, in the Maple PDEtools package , we have all the mathematical tools to tackle the equivalence problem around these solutions.

Examples

   

References

   

 

Download:  Digitizing_Mathematical_Information.mw,    Digitizing_Mathematical_Information.pdf

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

I have tried everything to find out how to customise the header and footer for my tutor marked assignments. 

I want to have a heading on the top of the page which has a continuous line running underneath the text of the heading. And I want to have a footing on the bottom of each page which has a continuous line running above the text of the footing text.

I noticed that the 2015 Maple user manual has this feature so it must be possible.

I cannot see how to do this using the standard customise header and footer menu.

Thanks in anticipation of an answer.

DLW

Hello guys, i have some matrix equations.

A^(T)*X+X*A+Q = 0 , where A,Q - matrixs, X - unknown matrix, i need to solve this.

i tried to solve this from http://www.mapleprimes.com/questions/200940-How-To-Solve-Matrix-Equation-Problem-In-Maple#answer203570 methods, but not successfully.

How can to solve this problem?

multMatrix.mw

thx.

A string is wound symmetrically around a circular rod. The string goes exactly
4 times around the rod. The circumference of the rod is 4 cm and its length is 12 cm.
Find the length of the string.
Show all your work.

(It was presented at a meeting of the European Mathematical Society in 2001,
"Reference levels in mathematics in Europe at age16").

Can you solve it? You may want to try before seing the solution.
[I sometimes train olympiad students at my university, so I like such problems].

restart;
eq:= 2/Pi*cos(t), 2/Pi*sin(t), 3/2/Pi*t; # The equations of the helix, t in 0 .. 8*Pi:
               
p:=plots[spacecurve]([eq, t=0..8*Pi],scaling=constrained,color=red, thickness=5, axes=none):
plots:-display(plottools:-cylinder([0,0,0], 2/Pi, 12, style=surface, color=yellow),
                         p, scaling=constrained,axes=none);
 

VectorCalculus:-ArcLength(<eq>, t=0..8*Pi);

                           20

 

Let's look at the first loop around the rod.
If we develop the corresponding 1/4 of the cylinder, it results a rectangle  whose sides are 4 and 12/4 = 3.
The diagonal is 5 (ask Pythagora why), so the length of the string is 4*5 = 20.

 

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

A student of mine has a problem, when trying to open a *.mw file directly from Finder, by double clicking og right-click and choose Open or Open with.  

Maple will prompt - the file does not exist.

 

If she uses Maple and and opening the same file thru file -> open etc. There is no problem. 

 

Any suggestions?

Kind regards 

Per Kirkegaard

 

 

Hello,

To summarize, I have a variable ε = order(1),  which maple has assumed is a funtion ε(x,y,z) and so when I differentiate epsilon with respect to x (or y or z) I do not get 0. I get ε(or εy, εz). How do I ensure maple does not assume this?

More detail of my process:

I declare functions,

I have the function I want to transform,

Now I transform the variables to the new co-ordinate system. i.e. from (x,n,q) to (s,Y,z)

                   

Good! - Everything correct so far. 

Now I want to linearise so i introduce x=x0+ε*x1; and the same for (Y,z), 

               

As you can see, epsilon has derivatives, which it should not. 

How I can avoid this? 

Thanks in advance - im well and truely stumped over this.

P.s. if the images do not show, the script can be found here: 

https://www.dropbox.com/sh/34gepa60xf4droq/AAAJlUcQ_Jwkc96topPvcxtXa?dl=0 

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