I need to make my base class local variable static, so that when extending the class, the subclass will share these variable and use their current values as set by the base class. If I do not make them static, then the base class when extended, will get fresh instance of these variable, losing their original values, which is not what I want.

To do this, one must make the base class variables static

This works, but now I do not know the syntax where to put the type on the variable. 

I can't write   local m::integer::static; nor local m::static::integer;

I could only write local m::static; but this means I lost the ability to have a type on the variable and lost some of the type checking which is nice to have in Maple. From Maple help:

Here is example

restart;

base_class:=module()
  option object;
  local n::static;  #I want this type to ::integer also. But do not know how

  export set_n::static:=proc(_self,n::integer,$)
     _self:-n := n;
  end proc;
  
  export process::static:=proc(_self,$)
    local o;
    o:=Object(sub_class);
    o:-process();
  end proc;
end module;    

sub_class:=module()
   option object(base_class);
   process:=proc(_self,$)
      print("in sub class. _self:-n = ",_self:-n);
   end proc;
end module;

o:=Object(base_class);
o:-set_n(10);
o:-process()


            "in sub class. _self:-n = ", 10

The above is all working OK. I just would like to make n in the base class of type ::integer as well as ::static

Is there a syntax for doing this?

Could any one please guide me how to show this solution by using Newton Raphson method. I need to show this solution step by step as shown in example.

Hi Community, I have solved the some basic expression by using built in command to get solution. Now i am interested to view the solution stp by step to show  my students of grade 10.

Download Help_to_view_solution_step_by_step.mw

Perhaps someone knows this. So I came across something recently and I can't recall if it was in this forum (which I can't find)

It was a value using some combinations of the constants e and Pi where the answer was very close to a whole number x.99939 or something.  The only thing I can remember is that it was exp(Pi)*...  I thought it was an answer written by Joe Riel where someone would use that to verify if the floating points... well I can't recall. 

Would anyone have an idea?

Do you know why increasing the number of applications of trapezoidal rule results infinity and imaginary part?

I want get result for Romberg Integration Method with 6 Applications of Trapezoidal Rule.

Download question.mw

Hi,

One of my areas of expertise is in Designer Filters EMC. Could any professional that already uses MapleFlow for EMC and Electromagnetism, help me about the main functions of this amazing software?

Thanks.

Leandro Zamaro

A small annoyance, when some code is copied from mapleprimes and pasted into Maple (the standard windows copy-paste ctrl+c   ctrl+v) and executed.  The code doesn't execute properly. 

For example

cprint:=proc(s,c)
nprintf("#mo(%A,mathcolor=\"%A\")",s,c):
end proc:

cprint("this is green",green);#prints green

cprint("this is green",red);#prints red

copying and pasting the above code in Maple and executing results in the following output

Not sure why?

Hello,

I'm working through a manual to improve my use of Maple commands.  In particular, earlier today I used/entered the circle command in the Geometry package.  I used that command circle successfully.  Later in the day I went to do the circle command again and I kept getting the message as shown below.  Same command, different result.  So I haven't been able to complete my tutorial.  I'd love to know what I'm doing wrong here.  The other time it worked perfectly.   Hope you can help, thanks Dave.

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.

Download OO_version.mw

Hello,

This might sound silly, but 

how do you find a tangent line equation at an exact point of a curve?

>TangentLine(curve,var);

I know this method but how can i put the exact point like (0,1) for an example?

Some of the examples would be very helpful! Thank you

I have a set of formulas I saved in a matrix and the exported the matrix to Excel. However when I open the file in Excel the equations are in prefix notation (I think).  That's not exactly human readable friendly.  If I copy and paste straight into excel they are readable.

It there a way to make the Maple export similar?

EDIT:-  I exported as a.csv file because if export as .xlsx    all the equation change into "#NUM!" in the spreadsheed.

Download test_eqn_export.mw

I am trying to plot the following kind of sequence. I was expecting a curve for one set of [] inside plot command, but I am getting twin curve there. How can I get a single curve for one single parametric command there. Please reply asap.

plot([[(1.428571429*(r^2+.49-4*r*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2)))*csc((1/3)*Pi), sqrt(16*r^2*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2)^2+.49*cos((1/3)*Pi)^2-2.040816327*(r^2+.49-4*r*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2))^2*cot((1/3)*Pi)^2), r = -10 .. 10], [(1.428571429*(r^2+.49-4*r*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2)))*csc((1/3)*Pi), -sqrt(16*r^2*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2)^2+.49*cos((1/3)*Pi)^2-2.040816327*(r^2+.49-4*r*(r^2+.49-2*exp(-.1/r))/(2*r-.2*exp(-.1/r)/r^2))^2*cot((1/3)*Pi)^2), r = -10 .. 10], [(5.*(r^2+0.4e-1-4*r*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2)))*csc((1/3)*Pi), sqrt(16*r^2*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2)^2+0.1e-1*cos((1/3)*Pi)^2-25.*(r^2+0.4e-1-4*r*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2))^2*cot((1/3)*Pi)^2), r = -10 .. 10], [(5.*(r^2+0.4e-1-4*r*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2)))*csc((1/3)*Pi), -sqrt(16*r^2*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2)^2+0.1e-1*cos((1/3)*Pi)^2-25.*(r^2+0.4e-1-4*r*(r^2+0.4e-1-2*exp(-.2/r))/(2*r-.2*exp(-.2/r)/r^2))^2*cot((1/3)*Pi)^2), r = -10 .. 10]], -13 .. 5, -5 .. 5)

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

Hi.

What wrong could be there with the color line?

Download Legend_Inside.mw

How can we export image with minimum size? I plot the solution and then export the image as an .eps file. But when I try to generate the generate the pdf file on Latex, the file size is too large. But when I plot the solutions on Matlab and export the images as .eps file, then Latex generate pdf file with samll size. Why Maple generate images of large sizes?

solution.mw