nm

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These are questions asked by nm

The suggested solution in the answer https://mapleprimes.com/questions/234325-Use-Of-self--Inside-Object-Constructor  worked OK in the setup shown in that question.

But it does not work when putting the constructor inside overload

Here is an example where it works (i.e. by removing the type from _self as suggested in the above answer)

restart;

person:=module()
    option object;
    local name::string:="";

    #notice no _self::person, just _self
    export ModuleCopy::static:= proc( _self, proto::person, the_name::string, $ )            
           name:= the_name;
    end proc;

end module;


p:=Object(person,"me")

The above works. But since I have different constructors, once I put the above inside overload, using the same exact syntax, now the error comes back

restart;

person:=module()
    option object;
    local name::string:="";

    export ModuleCopy::static:= overload( 
    [
       proc( _self, proto::person, the_name::string, $ ) option overload;           
           name:= the_name;
      end proc
    ]);

end module;
             

p:=Object(person,"me")

Error, static procedure `ModuleCopy` refers to non-static local or export `name::string` in surrounding scope

I did not expect that using overload will cause any change to how it behaves. Is this a bug?

Below is worksheet also.

interface(version);

`Standard Worksheet Interface, Maple 2022.1, Windows 10, May 26 2022 Build ID 1619613`

restart;

person:=module()
    option object;
    local name::string:="";

    export ModuleCopy::static:= proc( _self, proto::person, the_name::string, $ )            
           name:= the_name;
    end proc;

end module;

_m2950059551392

p:=Object(person,"me")

_m2950172920000

restart;

person:=module()
    option object;
    local name::string:="";

    export ModuleCopy::static:= overload(
    [
       proc( _self, proto::person, the_name::string, $ ) option overload;           
           name:= the_name;
      end proc
    ]);

end module;

_m2950059551392

p:=Object(person,"me")

Error, static procedure `ModuleCopy` refers to non-static local or export `name::string` in surrounding scope

 

Download OO_version.mw

I noticed in object constructor I had to write  _self:-name  to refer to object own variable called name.  But inside a another proc I can use just name without having to add _self:- to it. It also works when adding _self:-

Is this becuase constructor is special proc, and the object is not yet full constructed?  Here is a MWE

restart;
person:=module()
    option object;
    local name::string:="";

    export ModuleCopy::static:= proc( _self::person, proto::person, the_name::string, $ ) 
            print("Enter  constructor");
           _self:-name:= the_name;

           #Why this fails here, but not in process proc? Is it because of special
           #case since done inside constructor?
           #print(name); 

           print(_self:-name);
    end proc;
 
   export process::static :=proc(_self,$)
     #here both cases work
     print(_self:-name);
     print(name);
   end proc;

end module;

#and now

p:=Object(person,"me")

The above works. But if I uncomment #print(name); inside the constructor, maple gives error

p:=Object(person,"me")
Error, static procedure `ModuleCopy` refers to non-static local or export `name::string` in surrounding scope

But this works with no error

p:-process()

                              "me"
                              "me"

But no such error when doing same thing inside a local static proc inside same module.

Is this special just for the constructor than one must use :-self ? Just wanted to make sure.

Maple 2022.1

To Maple support,

Why when removing symbol a from these equations makes Maple warning go away? This is from a textbook. Attached worksheet. 

 

restart;
ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*a*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

restart;
ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

worksheet attached also

interface(version)

`Standard Worksheet Interface, Maple 2022.0, Windows 10, March 8 2022 Build ID 1599809`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1230 and is the same as the version installed in this computer, created 2022, April 21, 9:8 hours Pacific Time.`

restart;

ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*a*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

{(diff(x__1(t), t))*sin(x__2(t)) = x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)), diff(x__3(t), t)+(diff(x__1(t), t))*cos(x__2(t)) = 1, diff(x__4(t), t)-(1-B)*a*x__5(t) = sin(x__2(t))*cos(x__3(t)), diff(x__5(t), t)+(1-B)*a*x__4(t) = sin(x__2(t))*sin(x__3(t)), diff(x__2(t), t) = x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t))}

Warning, it is required that the numerator of the given ODE depends on the highest derivative. Returning NULL.

restart;

ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

{(diff(x__1(t), t))*sin(x__2(t)) = x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)), diff(x__3(t), t)+(diff(x__1(t), t))*cos(x__2(t)) = 1, diff(x__4(t), t)-(1-B)*x__5(t) = sin(x__2(t))*cos(x__3(t)), diff(x__5(t), t)+(1-B)*a*x__4(t) = sin(x__2(t))*sin(x__3(t)), diff(x__2(t), t) = x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t))}

 

Download warning_may_10_2022.mw

To Maple support:

I was investigating this pde from a different forum.

I noticed that when using an expanded version of the pde, Maple hangs. Without expanding the PDE, Maple gives an answer in 2 seconds. 

Why does expanding the PDE makes a difference? I do not have an earlier version of Maple on my new PC to check if this is a new issue or not.
 

interface(version);

`Standard Worksheet Interface, Maple 2022.0, Windows 10, March 8 2022 Build ID 1599809`

Physics:-Version()

`The "Physics Updates" version in the MapleCloud is 1230 and is the same as the version installed in this computer, created 2022, April 21, 9:8 hours Pacific Time.`

restart;
pde1:=VectorCalculus:-Laplacian(u(r,theta),'polar'[r,theta]);
pde1_expanded:=expand(pde1);
bc  := u(1,theta)=sin(theta)^4,u(3,theta)=1;
pdsolve([pde1=0,bc],u(r,theta))
 

(diff(u(r, theta), r)+r*(diff(diff(u(r, theta), r), r))+(diff(diff(u(r, theta), theta), theta))/r)/r

(diff(u(r, theta), r))/r+diff(diff(u(r, theta), r), r)+(diff(diff(u(r, theta), theta), theta))/r^2

u(1, theta) = sin(theta)^4, u(3, theta) = 1

u(r, theta) = (1/52480)*((328*r^6-26568*r^2)*ln(3)*cos(2*theta)+(-r^8+6561)*ln(3)*cos(4*theta)+19680*(ln(3)+(5/3)*ln(r))*r^4)/(ln(3)*r^4)

pdsolve([pde1_expanded=0,bc],u(r,theta)); #HANGS, Waited more than 40 minutes.

 


 

Download hangs_pde.mw

To Maple support:

I see 2 problems here. Maple solves the ode using series method.

First problem: Using odetest shows the syntax according to help does not work. Which is

           odetest(sol, ODE, series, point = 0);

The above gives internal error.

When changing to the following syntax

         odetest(sol,ODE,type='series',point=0); 

No internal error.

So help page should be corrected.

The second problem is that Maple odetest does not return 0 on its own solution. I verified manually that the solution is correct actually. So I do not know why maple does not return zero here. Simplfication does not help. 
 

interface(version);

`Standard Worksheet Interface, Maple 2022.0, Windows 10, March 8 2022 Build ID 1599809`

restart;

Order:=6;
ode:=x^2*diff(diff(y(x),x),x)+x^2*diff(y(x),x)+y(x) = 0;
maple_sol:=dsolve(ode,y(x),type='series',x=0):
odetest(maple_sol,ode,series,point=0);
odetest(maple_sol,ode,'series',point=0);

6

x^2*(diff(diff(y(x), x), x))+x^2*(diff(y(x), x))+y(x) = 0

Error, (in odetest/series) complex argument to max/min: 13/2-1/2*I*3^(1/2)

Error, (in odetest/series) complex argument to max/min: 13/2-1/2*I*3^(1/2)

odetest(maple_sol,ode,type='series',point=0); #This should return zero, but it does not.

-I*3^(1/2)*x^(3/2-((1/2)*I)*3^(1/2))*(series(-1/2-(I*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2)))*x-((1/4)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^2-((1/6)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3-((7/16)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^4+O(x^5),x,5))*_C1+((1/2)*I)*3^(1/2)*x^(3/2+((1/2)*I)*3^(1/2))*(series(1-(1/2)*x+(((1/2)*I)*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2)))*x^2-((1/12)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x^3+((1/24)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^4-((7/80)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^5+O(x^6),x,6))*_C2+_C1*x^(5/2-((1/2)*I)*3^(1/2))*(series(-I*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2))-((1/2)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x-((1/2)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^2-((7/4)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3+O(x^4),x,4))+_C2*x^(5/2+((1/2)*I)*3^(1/2))*(series(I*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2))-((1/2)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x+((1/2)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^2-((7/4)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^3+O(x^4),x,4))+_C1*x^(3/2-((1/2)*I)*3^(1/2))*(series(-1/2-(I*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2)))*x-((1/4)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^2-((1/6)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3-((7/16)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^4+O(x^5),x,5))+_C2*x^(3/2+((1/2)*I)*3^(1/2))*(series(-1/2+(I*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2)))*x-((1/4)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x^2+((1/6)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^3-((7/16)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^4+O(x^5),x,5))-((1/2)*I)*3^(1/2)*x^(3/2-((1/2)*I)*3^(1/2))*(series(1-(1/2)*x-(((1/2)*I)*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2)))*x^2-((1/12)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3-((1/24)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^4-((7/80)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^5+O(x^6),x,6))*_C1+I*3^(1/2)*x^(3/2+((1/2)*I)*3^(1/2))*(series(-1/2+(I*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2)))*x-((1/4)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x^2+((1/6)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^3-((7/16)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^4+O(x^5),x,5))*_C2+x^(5/2-((1/2)*I)*3^(1/2))*(series(-1/2-(I*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2)))*x-((1/4)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^2-((1/6)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3-((7/16)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^4+O(x^5),x,5))*_C1+x^(5/2+((1/2)*I)*3^(1/2))*(series(-1/2+(I*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2)))*x-((1/4)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x^2+((1/6)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^3-((7/16)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^4+O(x^5),x,5))*_C2+(1/2)*x^(3/2-((1/2)*I)*3^(1/2))*(series(1-(1/2)*x-(((1/2)*I)*3^(1/2)/((I*3^(1/2)-1)*(I*3^(1/2)-2)))*x^2-((1/12)*((5*I)*3^(1/2)+3)/((I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^3-((1/24)*((8*I)*3^(1/2)+9)/((I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^4-((7/80)*((3*I)*3^(1/2)+5)/((I*3^(1/2)-5)*(I*3^(1/2)-4)*(I*3^(1/2)-3)*(I*3^(1/2)-2)*(I*3^(1/2)-1)))*x^5+O(x^6),x,6))*_C1+(1/2)*x^(3/2+((1/2)*I)*3^(1/2))*(series(1-(1/2)*x+(((1/2)*I)*3^(1/2)/((1+I*3^(1/2))*(I*3^(1/2)+2)))*x^2-((1/12)*((5*I)*3^(1/2)-3)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)))*x^3+((1/24)*(-9+(8*I)*3^(1/2))/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)))*x^4-((7/80)*((3*I)*3^(1/2)-5)/((1+I*3^(1/2))*(I*3^(1/2)+2)*(I*3^(1/2)+3)*(I*3^(1/2)+4)*(I*3^(1/2)+5)))*x^5+O(x^6),x,6))*_C2

 


 

Download problems_with_series_solution.mw

 

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