Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

I often create diagrams in Maple and export them so I can embed them in a Word Doc.  Lately, when I right-click on the picture so I can select "export," the entire program closes.   It seems to happen more when the picture is in 3D.   Am I doing something wrong?     Thanks.

           David

Hi, I am trying to enter into the Mini-Course Computer Algebra for Physicists from the help, but instead of going to the page I get the help page of Physics[FeynmanIntegral]. Can anyone confirm that this happens to them on Maple 2021.2?

Kevin

Sorry to bother moderators again but a question from @panke has just disappeared.
I browsed its old questions but found none in a recent past related to the one removed.
Can you please tell me where it has been moved ?

TIA

PS: I understand perfectly the need to avoid multiple occurrences of a same thread, but in case of the displacement of a question, couldn't a systematic message be sent?

But ODEsteps supports simliar ODEs (see attached).
Is the ODESteps command not generic enough to cover the pendulum or have I missed something?

ODESteps.mw

I can't move files in the navigator window anymore in Maple 2021.2.

Anyone else with the same problems?

Other than saving few bytes of memory, why would one use ::static for methods of Object?

I found that if I use ::static, then I have to add prefix _self:- each time an object data member is referenced anywhere, making the code very hard to read.

Imagine having to write  _self:-x + 3* _self:-x^2 + 2* _self:-y^3 and so on all the time, instead of just x+3*x^2+2*y^3. (where it is assumed here that x,y happened to be object private data members and not local variables for a proc inside the module).

But then I found if I remove  ::static now _self:- no longer needed and can still get the benefit of using the object and the code works as before, but the code is now much more readable. 

I know that by not using static, then a copy of each method is made for each new object.

I am OK with that. As I do not use that many objects any way (few at a time before GC cleans the ones I used).

But the benefit of much more readable code far outweights the little extra memory needed, and memory is cheap these days anyway. I got lots of RAM. An extra few MB's is not a big deal.

What Am I missing here? Why does all the Maple help and documenation say that one should use static for object methods then? But do not mention that by not using static:: then the code will become more readable since _self:- is not needed to be appeneded to each variable or method name.

Here is an example below to compare. 

First example uses ::static methods, and the second does not.

One can see the difference The code is more clear in the second.   Is there something else I am overlooking by not using ::static . I am still learning OOP in Maple, and could be overlooking something else. I definitly do not want to code using _self:-variable_name all the time if I have to use OOP in Maple as it makes the code hard to read. 

Notice that in both examples, and for the exported methods, I used _self as first argument. This is OK. This is meant to allow client of the object to call it using object:-method() syntax which is what I prefer instead of method(object,....). syntax.

I am talking about the execssive use of _self internal to the module/object code when having to use ::static. methods.

restart;

person_class_STATIC:=module()
   option object;
   local age:=5;   

   export set_age::static:=proc(_self,age,$)      
     _self:-age:=age:
   end proc:      

   export update_age::static:=proc(_self,age,$)      
      do_the_update(_self)
   end proc:      

   local do_the_update::static:=proc(_self,$)
      _self:-age:=_self:-age+1;
      _self:-age:=sqrt(_self:-age^2+3);
   end proc;

   export get_age::static:=proc(_self,$)      
     return _self:-age;
   end proc:      

end module:

o:=Object(person_class_STATIC);
o:-set_age(100);
o:-get_age();
o:-update_age();

o2:=Object(person_class_STATIC);
o2:-get_age();

_m1982588380672

100

100

2*2551^(1/2)

_m1982698669216

5

person_class_NO_STATIC:=module()
   option object;
   local age:=5;   

   export set_age:=proc(_self,_age,$)      
     age:=_age:
   end proc:      

   export update_age:=proc(_self,$)      
      do_the_update()
   end proc:      

   local do_the_update:=proc()
      age:=age+1;
      age:=sqrt(age^2+3);
   end proc;

   export get_age:=proc(_self,$)      
     return age;
   end proc:      

end module:

o:=Object(person_class_NO_STATIC);
o:-set_age(100);
o:-get_age();
o:-update_age();

o2:=Object(person_class_NO_STATIC);
o2:-get_age();

_m1982698652256

100

100

2*2551^(1/2)

_m1982698629312

5

 

Download OOP.mw

Hi, I'm trying to solve auxilary equation to find its familes but I don't know what I'm doing wrong as I'm using following code:

famtemp := (diff(z(xi), xi))^2-a*z(xi)^2-b*z(xi)^3-c*z(xi)^4;

fam1 := simplify(`assuming`([dsolve(famtemp)], [b::real, a::real, c::real, -4*a*c+b^2 > 0, a > 0]))

I want to get the following family:

fam1 := 2*a*sech(sqrt(a)*xi)/(sqrt(-4*a*c+b^2)-b*sech(sqrt(a)*xi));

I hope someone will help me to solve it.

Thanks

HOW TO DECIDE THE TRIPLE INTEGRAL IS POSITIVE, NEGATIVE OR ZERO WITHOUT CALCULATING IT?

Hey guys,

How can I create a bar chart or a column chart, with specific x values under the bars.

Would be great If someone could help me.

Thank you;) 

Is there some basis containing polynomials of the form x[1]^p*x[2]^q+x[2]^p*x[3]^q+x[3]^p*x[1]^q, (p,q posint)?
Are there known relationships between these?

Note: these are not the symmetric polynomials.

I want to arrange this equation in term of powers of x and then plot the  real and imagenery part of x vs y. How can I do this with Maple?
1-alpha*((1/x^2)+(1/(x-y)^2)+(1/(x+ay)^2))=0;

1.mw     (alpha and a are constant, for example alpha=1 and a=0.3)

Does anyone by any chance know why I might be getting this error?

I'm working with polynomials that have coefficients with many digits (16).

Thank you in advance,

Who deleted my post - "How to factor out specific parts from expression"

Hi,

I want to solve system of  PDE equations by maple and i dont know how can i write it codes that can solve them for me. Can anyone help me please??!!

 

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