Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

I know that whattype() is used to find the basic data type of an expression. Unfortunately that information is rarely useful. How can I dig down deeper and get Maple to tell me more about the expression?

I read somewhere that there is a properties() procedure that does that but I cannot find that procedure.

Thanks.

Quite accidentally I discovered incorrect calculation of the simple definite integral:

int(1/(x^4+4), x=0..1);  

evalf(%);

                            1/8*ln(2)-1/16*ln(5)+1/32*Pi+1/8*arctan(1/3)   # This is incorrect result

                                                   0.1244471178

Is this a known bug?

 

If  first we calculate corresponding indefinite integral, and then by the formula of Newton - Leibniz, that everything is correct:

F:=int(1/(x^4+4), x):

eval(F, x=1)-eval(F, x=0);

evalf(%);

                                             1/16*ln(5)+1/8*arctan(2)

                                                     0.2389834593

 

 

In a recent blog post, I found a single rotation that was equivalent to a sequence of Givens rotations, the underlying message being that teaching, learning, and doing mathematics is more effective and efficient when implemented with a tool like Maple. This post has the same message, but the medium is now the Householder reflection.

Given the vector x = , the Householder matrix H = I - 2 uuT reflects x to y = Hx, where I is the appropriate identity matrix, u = (x - y) / ||x - y|| is a unit normal for the plane (or hyperplane) across which x is reflected, and y necessarily has the same norm as x. The matrix H is orthogonal but its determinant is -1, making it a reflection instead of a rotation.

Starting with x and uH can be constructed and the reflection y calculated. Starting with x and yu and H can be determined. But what does any of this look like? Besides, when the Householder matrix is introduced as a tool for upper triangularizing a matrix, or for putting it into upper Hessenberg form, a recipe such as the one stated in Table 1 is the starting point.

In other words, the recipe in Table 1 reflects x to a vector y in which all entries below the kth are zero. Again, can any of this be visualized and rendered more concrete? (The chair who hired me into my first job averred that there are students who can learn from the general to the particular. Maybe some of my classmates in graduate school could, but in 40 years of teaching, I've never met one such student. Could that be because all things are known through the eyes of the beholder?)

In the attached worksheet, Householder matrices that reflect x = <5, -2, 1> to vectors y along the coordinate axes are constructed. These vectors and the reflecting planes are drawn, along with the appropriate normals u. In addition, the recipe in Table 1 is implemented, and the recipe itself examined. If you look at the worksheet, I believe you will agree that without Maple, the explorations shown would have been exceedingly difficult to carry out by hand.

Attached: RHR.mw

I have the following problem consisting of multiple seteps.

I have a vector equation consisting of n equations with n parameters (a[n]). Usually the n <= 15. As example data I will use the case n=4.

equations := Vector[column]([ a[1], a[2], a[3],a[4]])-Vector[column]([ b[1], b[2], b[3],b[4]])=0;

The first thing I want to create is a matrix with a format 2^n x n (here: rows=16 by columns=4). The matrix only consists of ones and zeros which contains all possible combinations of ones and zeros. E.G. for n=4

subsMatrix := Matrix([[ 0 , 0 , 0 , 0 ],[ 1 , 0 , 0 , 0 ],[ 0 , 1 , 0 , 0 ],[ 0 , 0 , 1 , 0 ],[0 , 0 , 0 , 1],[1, 1 , 0 , 0],[1, 0 , 1 , 0],[1, 0 , 0 , 1],[0, 1 , 1 , 0],[0, 1 , 0 , 1],[0,0,1,1],[1, 1 , 1 , 0],[1, 1, 0 , 1],[1, 0 , 1 , 1],[0, 1 , 1 , 1],[1, 1 , 1 , 1]]);

Question 1: How do I create such a matrix for the general case? I have absolutely no idea how to achieve this with Matple

The next thing I want to do is to use the rows as substitution equations for the a[i] values, only if the value of the subsMatrix is 0. E.G. in the first case I want to set a[1]=a[2]=a[3]=a[4]=0, then a[2]=a[3]=a[4]=0, then a[1]=a[3]=a[4]=0, and so forth and save the equation as a new equation

I tried the following:

rows:=RowDimension(subsMatrix);

columns:=ColumnDimension(subsMatrix);

for i from 1 by 1 while  i<=rows do

                 subsEquations[i]:=equations

                 for j from  1 by 1 while  j<=columns do

                     if subsMatrix[i,j] =0 then

                          subsEquations[i]:= subs(a[j]=subsMatrix[i,j],subsEquations[i]) 

                     else      

                          #do nothing if the value in the subsMatrix[i,j]=1

                     end if

                 end do:    

end do:

Question 2: What is my error? Maple says the loop is indeterminate. But I don't see why it is not working.

 


I would be thankful if someone could help me out. I am open to other kind of strategies to this problem :).

what would i write if i wanted to display the full list of variables that be specified by calling kernelopts? like as output in the interface, i naively attempted ops(kernelopts)  which didnt work of course.

It is very important that you learn to pose and solve equations in practical problems. Ernest Mach, a famous scientist of the nineteenth century, said that algebra is characterized by a lightening of mind, because the solution of a problem, after building the equation, you can "forget" all the practical situation to focus on the mathematical expression; everything that is not necessary to solve the problem no longer interfere with your mind. Another famous scientist, Isaac Newton, wrote that the language of algebra is the equation. To see a problem concerning abstract relations of numbers or amounts, simply translate the problem of colloquial language to the algebraic language. Here I leave the application for first order equations developed in 2016 Maple.

 

Aplicativo_Ecuaciones.mw

(In Spanish)

Lenin Araujo Castillo

Ambassador of Maple - Perú

 

 

 

 

 

Can we calculate the following equations in Maple?

Substituting equations (21) and (22) into (17), and then obtain equation (23). How to do that? I have done this, but the results are complex and large. They are not in a sum form, but in an expansion form. The reference and the maple file are attached.

Hope for your help.

Best wishes,

Kang

Dynamic_buckling_of_thin_isotropic_plates_subjected_to_in-plane_impact.pdf

gg.mw

Recently, entered a engineering graduate program and will be taking a graduate engineering class in my retirement.  In our Into classes we reviewed engineering math through ODE. In the second class, we performed some numerical methods using MatLab with a small introduction.  My formal Math wass in the 1980s, but now have to fire it up for a Engineering Analysis using Michael Greenberg's Advanced Engineering Mathematics, 2nd which has Maple imbedded code and directions.

 

What would be my assignment for getting up to speed with using Maple to solve algebraic-symbol-programming problems? For instance, which tutorials in what order, or webinars? i think I once had Fortran 77 and remember zip.

 

Appreciate any good advice.

MathMan2

i tend to study a particular function each day, and noticed that the CAS literally ignores me when i as for an evaluation of the mellin transform for the lerch phi function. i just assume there to return an error if the function has properties that do not satisfy the criteria for a particular transform, in this case, null, it just pretends i didnt ask.

Assuming the maple kernel hasnt evolved conciousness and has decided to hate me im guessing someone else has run into similar circumstance.

Hello 

Is there a way to solve matrices symbolically?

an example would be A*X=B

where the answer would be 

X=A^-1B

 

I have tried to look for a thing in maple that will do this but so far i had no luck. Does anyone know ?

Thanks in advance

Hi,

I am trying to download some MapleSim Robotic models from the Maplesoft website but I have 'Invalid File Format' error. Could you help please?

Best

Onder

Given that I use Maple as a student I've had to update to the newest version to keep using Maple.

However I find I have a lot of problems with the new version.

 

Normally when I write an assignement or work on the given problems I use worksheet mode because it is the best mode to spot any mistakes, and I've grown accostumed to it.

 

My problem however is when I have to use text.

 

Normally I've hit CTRL+T to get Maple to recognize that I write text, whereupon I write the given assignment, and press CTRL+J for when I want to go on and write some math. However we do have a little issue about the symbols.

 

Since I am an engineering student we use a lot of greek letters, and in this case I bring up sigma. In the "old" Maple I pressed F5 to get into math, write the symbol I wanted, pressed F5 again to get back to text and keep writing. In Maple 2016 however I do the same and then at the end of the text paragraph maple spits out lines of blue text with all of the "math" that I have written.


So my question is thus: Can I stop Maple from giving me the blue text, or perhaps is there another way to type symbols without having to go into math?

What is the funcional difference between individual, academic, and professional editions of Maple?

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