Download HmaxProc.mw

I am currently unable to type in maple 2021, there is no cursor, nothing shows up when I type etc. I am also unable to save files. I went into document mode, nothing. Some of the dialogs don't show up. Where does maple save documents and how do I change that setting? That might be my problem. Furthermore, there are no tabs visable, like I can't access any documents I open.

I have the sphere x^2 + y^2 + z^2 =( 33*sqrt(3))^2 and I want to select four points on a sphere to make a regular tetrahedron so that its coordinates are integer numbers. I see this question is here https://mathematica.stackexchange.com/questions/289123/how-can-i-select-four-points-on-a-sphere-to-make-a-regular-tetrahedron-so-that-i
Time to get result is a problem. 

Due to a stupid typing mistake I get this error, "Error, too many levels of recursion". Now the program is frozen and I cannot get rid of the error.  Help!

How can a solve second order Laplace Equation with boundary condition numerical in Maple 2023?

Kjell

Hi,

Im trying to configure Maple's colors by modifying the X11_defaults/Maple file but nothing happens. I set the environment variable MAPLE to point to my Maple installation and load the previous file with xrdb. I am running dwm as my window manager in Arch Linux.

I am frustrated. All help is welcomed. If you have any suggestion for configuring dark mode in a different way, please share your arcane knowledge with me.

Thank you in advance.

I have an expression of the form X=a/f^b where a and b are both numeric. How do I elegantly extract the numerical values of "a" and "b" given X? See below for my kludge solution.

Download Extract.mw

I am slightly confused as I can't apply the seemingly correct function to a sequence. It seems like modp does not like my inverse. But I am not aware of any other way of finding the modular inverse.  

Download example.mw

restart;
alias(u = u(x, y, t), f = f(x, y, t));
                              u, f
u := (f+sqrt(R))*exp(I*R*t);
                    /     (1/2)\           
                    \f + R     / exp(I R t)
pde1 := I*(diff(u, t))+diff(u, x, x)+2*lambda*u*abs(u)*abs(u)-gamma*(diff(u, x, t));
   // d   \                /     (1/2)\             \
 I ||--- f| exp(I R t) + I \f + R     / R exp(I R t)|
   \\ dt  /                                         /

      / d  / d   \\           
    + |--- |--- f|| exp(I R t)
      \ dx \ dx  //           

               /     (1/2)\                           2 
    + 2 lambda \f + R     / exp(I R t) (exp(-Im(R t)))  

               2
   |     (1/2)| 
   |f + R     | 

            // d  / d   \\                / d   \             \
    - gamma ||--- |--- f|| exp(I R t) + I |--- f| R exp(I R t)|
            \\ dx \ dt  //                \ dx  /             /
 

I am using Maple 2023.

When using PDE Numeric Help Side the text sides is not smooth moving when scrolling downwards or upwards.

Any advice what to do????

Kjell

Hi,

I am looking to randomize the coordinates of the three non-aligned points A, B, C to generate random drawings of triangles. Thank you for your insights.

CaractTriangle.mw

The so-called look-and-say sequence is something like:

Rosetta Code gives an example of how to generate such sequences in Maple; however, the code in that example is lengthy. More to the point, compared to the subsequent Mathematica analogue, it is rather inefficient (though more readable, but that's not the point). 
I slightly modify the original code, and now the modified version is significantly faster than the original one: 
 

Download LookAndSay.mw

For the sake of convenience, I paste the original Maple code from the page above into here:

generate_seq := proc(s)
	local times, output, i;
	times := 1;
	output := "";
	for i from 2 to StringTools:-Length(s) do
		if (s[i] <> s[i-1]) then
			output := cat(output, times, s[i-1]);
			times := 1; # re-assign
		else 
			times ++;
		end if;
	end do;
	cat(output, times, s[i - 1]);
end proc:

Look_and_Say :=proc(n)
	local value, i;
	value := "1";
	print(value);
	for i from 2 to n do
		value := generate_seq(value);
		print(value);
	end do;
end proc:

#Test:
Look_and_Say(10);

Below is a modified version by me: 

LookAndSay := proc(m::posint, n::nonnegint := 1, $)::'Vector'(nonnegint);
    uses StringTools;
    local delete::'equationlist' := Repeat~(Explode(ExpandCharacterClass(":digit:")), 2), aux::procedure[nonnegint](posint) := proc(_::posint)::nonnegint;
        options cache;
        description "https://rosettacode.org/wiki/Look-and-say_sequence#Maple";
        if _ = 1 then
            n
        else
            local char::'nonemptystring' := String(thisproc(_ - 1)), temp::list(string)(*, str*);
            try
                temp := RegSplit(sprintf("(?=[%s])(?<=(?!%s)[%s])", Unique(char), Join(select[2](foldr, eval(apply), delete, rcurry(OrMap, Unique(char)), curry(curry, Has)), "|"), Unique(char)), char)
            catch "cannot compile regular expression: repetition-operator operand invalid":
                local rule::'equationlist' := (str -> str = Insert(str, 1, " "))~(subs(delete =~ NULL, Generate(2, Support(char))));
                temp := StringSplit(Subs(rule, char), " ") # to be replaced
            end;
            parse(String(seq('length(str), str[1]', str in temp)))
        fi;
    end;
    forget(aux);
    Vector[column](m, aux, datatype = nonnegint)
end:

The form LookAndSay(m, n); produces the first m terms in a "look-and-say" sequence starting with n (which is by default 1). Unfortunately, even if "the modified version is significantly faster than the original one", it is still much slower (25s versus 2.5s) than the uncompiled Mathematica implementation (on the same modern computer):

So, is there a workaround to evaluate LookAndSay(50, 1): in about three seconds (instead of half a minute) in the first call (without looking up a pre-calculated table) (on the same computer) as well? 

This is old question https://www.mapleprimes.com/questions/208909-Code-For-Integer-Points-On-Sphere. Now I see this question at here 
https://mathematica.stackexchange.com/questions/288956/how-can-i-get-all-squares-on-this-sphere-so-that-its-coordinates-are-integer-num
 My idea is select all diameters which diameters are perpendicularly from the sphere (x-2)^2 + (y-4)^2 + (z-6)^2 = 15^2. How can I tell Maple to do that?

HPMthesis.mw

how to plot graphs for both methods and comparison of different method values for Diff(f(eta),eta, eta) at eta =0

Download DTM_practice.mw