The (Induced) Subgraph Isomorphism computational problem is, given H and G, determine whether there is a (induced) subgraph isomorphism from H to G. See https://en.wikipedia.org/wiki/Induced_subgraph_isomorphism_problem

In Maple, IsSubgraphIsomorphic(G1,G2)  returns true if G1 is isomorphic to some subgraph of G2. However, it does not provide options for induced subgraphs. For example, 

with(GraphTheory):
claw:=CompleteGraph(1,3);
g:=CompleteGraph(2,2,2,2):
DrawGraph(g);
IsSubgraphIsomorphic(claw,g) #true

So the graph g contains a claw as a subgraph. But every claw in graph g  is non-induced. So g does not contain any induced claw. Maple does not appear to have this feature to determine if a graph contains a induced subgraph isomorphic to another graph. It is unclear whether we can modify some code in IsSubgraphIsomorphic  to achieve this goal.

Download n=1_analytical.mw

ode1 is Lane emden equation that can be solved analytically for n=0,1,5 .

For other values of n it needs to be solved numerically.

My question is how to proceed and use the numeric result in ode2 with bcs mentioned and get same or close result to analytical one. I am trying to verify alpha. In the worksheet i have chosen n=1 because i want to learn how to deal with numeric solution for which i already have the answer to verify. If ode2 also needs to to solved numeric its ok. The point is to get at the derivative value from various alpha values for different n like 3. Please help and let me know if additional info is needed.

This setup works, where B extends A, then B method access local variable in A directly, since it now becomes part of the object B itself

restart;
                            
module A()
  option object;
  local s::string:="";
end module;

module B()
   option object(A);
   export foo::static:=proc(_self,$)
      _self:-s := cat(_self:-s,"something");
      print(_self:-s);
   end proc:
end module;

o:=Object(B);
o:-foo()

Gives "something"

Now, I changed B, by adding an anonymous local proc() and did the same exact thing as above, which is to access s.

Now Maple complains that B does not export s

restart;

module A()
  option object;
  local s::string:="";
end module;

module B()
   option object(A);
   export foo::static:=proc(_self,$)
        proc()
            _self:-s:=cat(_self:-s,"somethig");
            print(_self:-s);
        end proc();
   end proc:
end module;

o:=Object(B);
o:-foo()

It gives

Error, (in anonymous procedure called from anonymous procedure) module `B` does not export `s`

Could someone help me understand why this happens? How it works in the first example but not in the second?  I do not see why it would make difference. isn't anonymous procedure part of the class that is being extended?

Update

It is worst than I thought. Even named local proc, inside method now fail. Here is an example

restart;

module A()
  option object;
  local s::string:="";
end module;

module B()
   option object(A);
   export foo::static:=proc(_self,$)
        local z::string:="something";
        local my_inner_proc:=proc()
            _self:-s:=cat(_self:-s,z);
        end proc();
        my_inner_proc();
   end proc:
end module;

o:=Object(B);
o:-foo()

Gives 

Error, (in anonymous procedure called from anonymous procedure) module `B` does not export `s`
I was using code which worked before, but now after extending the class, I am finding all these problems.

Is this documented something that local proc()'s inside method do not work as expected when extending classes in Maple OOP? It means now I have to move these local proc() to the outside of its current enclosing proc() to make Maple happy.  I just do not understand why this limitation.

Maple 2023.1 on Windows 10

integral of sqrt(sin(x)) is known to be as given in few place such as in here and other places.

Maple gives a result which is much more complicated (but also in terms of EllipticE special function). 

Could someone find a way to simplify it to the above answer and also to the same answer given by Mathematica?

int(sqrt(sin(x)),x)

Compare to 

Maple's result seems to be correct, as I plotted it and compared the smaller known resut. But I was not able to simplify it to obtain the smaller antiderivative.

Any tricks to do that?

Maple 2023.1 will not let me overload a method for an object when using _self.  Is there a way around this?

module person()
   option object;
   local the_name::string:="*",the_age;

   export set_info::static:= overload(
   [
      proc(_self,the_name::string,$) option overload;
          _self:-the_name:=the_name;
      end proc,

      proc(_self,the_name::string,the_age::integer, $) option overload;
          _self:-the_name:=the_name;
          _self:-the_age:=the_age;
      end proc
   ]);

   export get_name::static:=proc(_self,$)
      RETURN(_self:-the_name);
   end proc;
end module;

And now when I do 

o:=Object(person);
o:-set_info("me");
o:-set_info("me",20)

Error, (in person:-set_info) `me` does not evaluate to a module
Error, invalid input: no implementation of person:-set_info 
matches the arguments in call, 'person:-set_info("me",20)'

The problem goes away by removing `_self` as first argument in signature of the overloaded method. But then I will not be able to use _self any more inside the methods.

There is no problem overloading the method when using normal module, or one that does not use _self. For example this works

restart;

module person() 
   export set_info:= overload(
   [
      proc(the_name::string,$) option overload;
          print(the_name);
      end proc,

      proc(the_name::string,the_age::integer, $) option overload;
          print(the_name);
          print(the_age);
      end proc
   ]);
end module;

person:-set_info("me");
person:-set_info("me",20)

How to make the first example above work? I need to overload a method inside an module with option object that uses _self

update

I found a workaround. But it is not good, but for now. For the overloaded method, instead of using 
           o:-set_info("me");

This works instead

         set_info(o,"me");

So the following now works

o:=Object(person);

#o:-set_info("me");   #do not use with overloaded
#o:-set_info("me",20); #do not use with overloaded

set_info(o,"me");  #now works OK with no error
set_info(o,"me",20); #now works OK with no error

o:-get_name();  #OK since this method  is not overloaded
o:-get_age();  #OK since this method  is not overloaded

I do not understand why _self can't be used with overloaded methods and if this a bug or by design. 

Maple 2023.1 on windows 10

Download self_with_overloaded.mw

In short, I'd like to obtain n largest/smallest elements in a huge list of (probably non-numeric) data. Of cource I can sort it and then extract the desired part, yet isn't there a dedicated procedure that do a partial sort of the input data in Maple?

Edit. In a MatLab weblog, the blogger gave: 

So I believe that a dedicated one is not useless. But what is the Maple equivalent to MatLab's maxk, mink, and topkrows?

Hi all

I need your advice on Maple usage after a long break. I installed Maple on my laptop and first of all tried to launch my old program. Surprisingly, the old file opened. While the core Maple functionality remained familiar, the user interface had undergone some changes.

Yet, I soon encountered challenges when attempting to perform even the simplest operations, like file browsing or text selection; the Maple Standard GUI seemed uncharacteristically sluggish.  I switched to Maple Input mode but it didn't help much. Are there ways to improve my experience with Maple? Is it caused by the outdated hardware?

My system:
Ubuntu 22.04.3 LTS
Dell Inc. Latitude 5510 (1TB SSD, 32GB RAM).

Maybe it works much better on Windows?

Thank you for any suggestions.

I have a small problem that I can't find a solution for. How do you draw a diagram like the one shown in Maple? I can't figure out how to rotate the column labels or define tickmarks as text.

Can anyone help?

Hi, 

Some of my maple documents contain data tables. 

When I want to view these documents with the maple cloud viewer, the data tables are invisible (the table is completely grayed out) and it is therefore impossible to change the values in this table. 

The table properties are such that it is enabled, visible and editable. 
Does anyone have an idea how to solve this problem? 
Thanks in advance. 

Can anyone please assist with these errors?

Download Asst_4_Question_2c.mw

Both, Maple and MapleSim in Versions from 2021 to 2023 do not start. A logfile is saved which starts as

# A fatal error has been detected by the Java Runtime Environment:

#

#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x0000000000000000, pid=17256, tid=10520

#

# JRE version: OpenJDK Runtime Environment Temurin-19.0.1+10 (19.0.1+10) (build 19.0.1+10)

# Java VM: OpenJDK 64-Bit Server VM Temurin-19.0.1+10 (19.0.1+10, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, windows-amd64)

# Problematic frame:

# C  0x0000000000000000

#

This only occurs when the notebook (on which the error occurs) is connected to the domain network. If the notebook is not connected, Maple and MapleSim can be started and will continue to run when the network is reconnected.

Has anybody seen this before or any ideas what this could be?

Edit: This all happened under Windows 10 on a notebook that has been running Maple for 3 years and only recently displayed this error.

Edit2: Connection via an USB doc which also connects to an external monitor.

Since I have updated from Maple 2021 to 2023 something is wrong with my stylesheets.

I rephrase my qeustion here:

I like to change the text-style of 2D-Input to courant 12, bold, color x, no italic.

Now it is courant 12, black, italic when opening a new worksheet.

I was going to format, style, 2D-input, modify and then the font has changed when opening a new woksheet but the color is going back to black and its also italic courant when pressing enter in that worksheet.

I When opening a new worksheet, i don't want ot looad an new style set by hand every time.

Thanks for support

Good day to all the members who read this question.
I ask for your help to find the right way to solve this two differential equations (is attached the file). Used the common code "dsolve" but is not working on this problem. Doesn't matter if the solution is numeric or algebraic.
I will thaks a lot your kind help.
Best regards to all of you

DIFFERENTIAL_EQUATION.mw

Download DIFFERENTIAL_EQUATION.mw

Dear Power Users, I tried to make a model in Maple but after several hours of struggling I need some help. Can someone tell me what I did wrong or explain to me what is the meaning of the maplemint comment on procedure (optimalisatie)? Thank you in advance.

DiLeoCasper.mw 

For the t output I need to show 1, 1.2, 1.4....2, my attempt is highlighted in green below

Can anyone assist please?

Download Asst_4_Question_1f.mw