I am not desperatly seeking Susan but the code of the DoFit procedure (for what this early-year joke is worth)

showstat(Statistics:-LinearFit)  reveals LinearFit uses the procedure Statistics:-Regression:-LinearFit (lines 4 & 9).

Next
kernelopts(opaquemodules=false):
showstat(Statistics:-Regression:-LinearFit):
indicates the Maple procedure which really does the LinearFit has name DoFit (lines 6 & 16).

I spent some time using the Library assistant to try and find this procedure, in vain.
Where can I get the source of DoFit?

Thanks in advance.

almost i did all the case but some case i determined in red color are not satisfy what is problem of them and how i can apply the case 47-52, beside this i changed the ode in eq(15) i didn't write rho parameter  is make any problem?

ode-17.mw

Hello Ladies and Genlemen,

What is the command to display a list of *all* the packages in Maple ?

How do you insert an output for exemple (2.1.1) in a worksheet?

CTRL+K is inactive for me...it just adds a CRLF.

Thank you very much and kind regards,

Jean-Michel

The inscribed square problem, also known as the Toeplitz conjecture, is an unsolved quastion in geometry: Does every plane simple closed curve (Jordan curve) contain all four vertices of some square? This is true if the curve is convex or piecewise smooth and in other special cases. The problem was proposed by Otto Toeplitz in 1911. For detailes see  https://en.wikipedia.org/wiki/Inscribed_square_problem

The Inscribed_Square procedure finds numerically one or more solutions for a curve defined by parametric equations of its boundary or by the equation F(x,y)=0. The required parameter of procedure  L  is the list of equations of the boundary links or the equation  F(x,y)=0 . Optional parameters:  N  and  R . By default  N='onesolution' (the procedure finds one solution), if  N  is any symbol (for example  N='s'), then more solutions.  R  is the range for the length of the side of the square (by defalt  R=0.1..100 ).

The second procedure  Pic  visualizes the results obtained.

The codes of the procedures:

restart;
Inscribed_Square:=proc(L::{list(list),`=`},N::symbol:='onesolution',R::range:=0.1..100)
local D, n, c, L1, L2, L3, f, L0, i, j, k, m, A, B, C, P, M, eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9, sol, Sol;
uses LinearAlgebra;
if L::list then
L0:=map(p->`if`(type(p,listlist),[[p[1,1]+t*(p[2]-p[1])[1],p[1,2]+t*(p[2]-p[1])[2]],t=0..1],p), L);
c:=0;
n:=nops(L);
for i from 1 to n do
for j from i to n do
for k from j to n do
for m from k to n do
A:=convert(subs(t=t1,L0[i,1]),Vector): 
B:=convert(subs(t=t2,L0[j,1]),Vector):
C:=convert(subs(t=t3,L0[k,1]),Vector): 
D:=convert(subs(t=t4,L0[m,1]),Vector):
M:=<0,-1;1,0>;
eq1:=eval(C[1])=eval((B+M.(B-A))[1]);
eq2:=eval(C[2])=eval((B+M.(B-A))[2]);
eq3:=eval(D[1])=eval((C+M.(C-B))[1]);
eq4:=eval(D[2])=eval((C+M.(C-B))[2]);
eq5:=eval(DotProduct(B-A,B-A, conjugate=false))=d^2;
sol:=fsolve([eq1,eq2,eq3,eq4,eq5],{t1=op([2,2,1],L0[i])..op([2,2,2],L0[i]),t2=op([2,2,1],L0[j])..op([2,2,2],L0[j]),t3=op([2,2,1],L0[k])..op([2,2,2],L0[k]),t4=op([2,2,1],L0[m])..op([2,2,2],L0[m]),d=R});
if type(sol,set(`=`)) then if N='onesolution' then return convert~(eval([A,B,C,D],sol),list) else c:=c+1; Sol[c]:=convert~(eval([A,B,C,D],sol),list) fi;
 fi; 
od: od: od: od:
Sol:=fnormal(convert(Sol,list),7);
print(Sol);
ListTools:-Categorize((X,Y)->`and`(seq(is(convert(X,set)[i]=convert(Y,set)[i]),i=1..4)) , Sol);
return map(t->t[1],[%]);
else
A,B,C,D:=<x1,y1>,<x2,y2>,<x3,y3>,<x4,y4>:
M:=<0,-1;1,0>:
eq1:=eval(C[1])=eval((B+M.(B-A))[1]):
eq2:=eval(C[2])=eval((B+M.(B-A))[2]):
eq3:=eval(D[1])=eval((C+M.(C-B))[1]):
eq4:=eval(D[2])=eval((C+M.(C-B))[2]):
eq5:=eval(LinearAlgebra:-DotProduct((B-A,B-A), conjugate=false))=d^2:
eq6:=eval(L,[x=x1,y=y1]):
eq7:=eval(L,[x=x2,y=y2]):
eq8:=eval(L,[x=x3,y=y3]):
eq9:=eval(L,[x=x4,y=y4]):
sol:=fsolve({eq1,eq2,eq3,eq4,eq5,eq6,eq7,eq8,eq9},{seq([x||i=-2..2,y||i=-2..2][],i=1..4),d=R});
eval([[x1,y1],[x2,y2],[x3,y3],[x4,y4]], sol):
fi;
end proc:

Pic:=proc(L,Sol,R::range:=-20..20)
local P1, P2, P3, T;
uses plots, plottools;
P1:=`if`(L::list,seq(`if`(type(s,listlist),line(s[],color=blue, thickness=2),plot([s[1][],s[2]],color=blue, thickness=2)),s=L), implicitplot(L, x=R,y=R, color=blue, thickness=2, gridrefine=3));
P2:=polygon(Sol,color=yellow,thickness=0);
P3:=curve([Sol[],Sol[1]],color=red,thickness=3):
T:=textplot([[Sol[1][],"A"],[Sol[2][],"B"],[Sol[3][],"C"],[Sol[4][],"D"]], font=[times,18], align=[left,above]);
display(P1,P2,P3,T, scaling=constrained, size=[800,500], axes=none);
end proc:

Examples of use:

The curve consists of a semicircle, a segment and a semi-ellipse (find 1 solution):

L:=[[[cos(t),sin(t)],t=0..Pi],[[t,0],t=-1..0],[[0.5+0.5*cos(t),0.8*sin(t)],t=Pi..2*Pi]]:
Sol:=Inscribed_Square(L);
Pic(L,Sol);

The procedure finds 6 solutions for a non-convex pentagon:

 L:=[[[0,0],[9,0]],[[9,0],[8,5]],[[8,5],[5,3]],[[5,3],[0,4]],[[0,4],[0,0]]]:
Sol:=Inscribed_Square(L,'s');
plots:-display(Matrix(3,2,[seq(Pic(L,Sol[i]),i=1..6)]),size=[300,200]);

For an implicitly defined curve, only one solution can be found:

L:=abs(x)+2*abs(y)-sin((2*x-y))-cos(x+y)^2=3:
Sol:=Inscribed_Square(L);
Pic(L,Sol);

               
See more examples in the attached file.

Inscribed_Square.mw

I was searching release notes for some old Maple versions. I found so many broken links on Maple web pages. The first page is https://www.maplesoft.com/products/maple/history/ 

Scrolling down, and starting from Maple 2016 (about half way down the page), all links to the "product press release" are broken. This is the link to the right of each product.  All these links on the right, from 2016 to the end of the page are broken,

Clicking on any of these, sends the user to new broken web page, called https://www.maplesoft.com/company/publications/  titled "Maplesoft media coverage".

This page does not even work. Clicking on "Jump to year" does not open. Clicking in "first page" does nothing. Tried Edge browser on windows 10, also the page does nothing. 

Then I clicked on Maplesoft Media Releases link at top, and now it works.

But jumping to any year before  2016, all the links that show on those pages are broken. Try and see,

For example. jumping to 2015, and clicking on release called "

November 25, 2015"

Gives

This applies to each press release for each year from 2015 to 1997.

Hundreds of links are broken.

There is software which checks broken links, and it is free for windows, called Xenu's Link Sleuth. May be someone at Maplesoft can use it to find all broken links at Maplesoft web site and fix them?

It is not acceptable in this day and age to have a Major software company with a web site full of broken links.

Do not know if this known or reported or not. Just in case. Here is an example where odetest gives internal error when adding integer to assuming. 

Maple 2025.2. Firewall will not let me upload now. Here is code

sol:=y(x) = -4/9*I*(x+1)^(1/4)*(x-1)^(1/4)*2^(1/2)*x^2+4/9*(x+1)^(1/4)*(x-1)^(1/4)*2^(1/2)*x^2+4/9*I*(x+1)^(1/4)*(x-1)^(1/4)*2^(1/2)+1/9*x^4-4/9*(x+1)^(1/4)*(x-1)^(1/4)*2^(1/2)-16/9*I*(x+1)^(1/2)*(x-1)^(1/2)-2/9*x^2+1/9;
ode:=(-x^2+1)*diff(y(x),x)+x*y(x) = x*(-x^2+1)*y(x)^(1/2);
IC:=y(0) = 1;

odetest(sol,[ode,IC]) assuming integer,positive;

Screen shot

There used to be specific web pages, that lists specific update to Maple DE solver.

Only ones I can find are from version 8 to 16. Here are the links below. They start by saying this 

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple8/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple9/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple10/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple11/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple12/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple13/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple14/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple15/de

https://www.maplesoft.com/support/help/Maple/view.aspx?path=updates/Maple16/de

But these do not works for anything after Maple 16 and before 8. i.e. changing the number in the link to 17 or 18 and so on, gives no page found error.

All my search leads to no result.

Are such help pages still present for updates to DE solvers in Maple for versions after Maple 16? WHat link to use to access them?

When I look at web pages under "what is new" it also does not have specific section just for DE solver like those pages had. For example   https://www.maplesoft.com/support/help/maple/view.aspx?path=updates%2Fv2025  does not have specific section just for DE solvers.

 i wait 30 minute to  see the result of this function it will zero or not but is not give me outcome, is so importan for me which to see this function is my answer, how i can see the result, can  anyone give me the way 

T-pde.mw

Hi again all,

prime numbers are fun for me.

see

pairs_of_prime_numbers_procedure_with_union_and_isprime.pdf

sorry, could not find the .mw file,

but the code is small, and easy to copy

this is fun for me, here in Keizer OR, USA

Party on, everyone

Best regards,

Matt

https://mattanderson.fun/

I have the following data

Dados:=[-9.43, -4.42, -4.04, -2.88, -1.90, -1.81, -1.20, -1.16, -1.03, -.14, 1.27, 1.72, 1.97, 1.98, 2.24, 3.24, 3.64, 3.8, 5.1, 5.52]

and using command

Histogram(Dados, binbounds = [-10, -7, -4, -1, 2, 5, 8], frequencyscale = absolute)

I can create a frequency histogram for the classes [-10,-7[, [-7,-4[, [-4,-1[, [-1,2[, [2,5[, [5,8[. However, how I can create a cumulative histogram with corresponding polygon employing this same information? With thanks.

The system below obviously has the unique solution  t=3*Pi/2 , but Maple doesn't return any solution. I wonder if this bug persists in recent versions of Maple?

solve({cos(t)=0,sin(t)=-1,t>=0,t<=2*Pi}, t);

   #  NULL

I wanted to trick odetest and see what it does. I gave it solution to ode with IC. The solution was in form of implicit solution.

odetest verified it.

Then I solved for y(x) from the implicit solution and passed each now explicit solution to odetest, now it does not verify either one. (two explicit solutions resulted)

I would have thought that odetest to not verify the implicit solution as well. Is this a bug or an expected behavior when using implicit?

Does this mean, to be safe, one should try to solve for y(x) explicitly before using odetest? But sometimes this can be expensive or not possible nor practical to do as implicit solution can be complicated to solve for y(x).

Maple 2025.2 on windows 10.

Firewall now suddently will not let me upload a worksheet again for some reason. Firewall did not have a problem yesterday, but today it complained.

So here code and screen shot

restart;
ode:=2*y(x) + 2*x*y(x)^2 + (2*x + 2*x^2*y(x))*diff(y(x), x) = 0;
IC:=y(0) = 1;
maple_sol:=dsolve([ode,IC]);
#                         maple_sol := ()

my_sol_1:=x*y(x)*(2+y(x)*x)=0;
odetest(my_sol_1,[ode,IC])

#                             [0, 0]

PDEtools:-Solve(my_sol_1,y(x));
map(X->odetest(X,[ode,IC]),[%])

#   [[0, 1], [0, undefined]]

So I want to create gamma matrices like this one:

and the four Pauli matrices. So how can I create this one if I have defined the identity matrix (2X2) and the zero matrix(2X2).

 I have tried this:

with(LinearAlgebra);
ga_zero := matrix(4, 4, [ZeroMatrix(2), IdentityMatrix(2), -IdentityMatrix(2), ZeroMatrix(2)]);

Which, of course, did not work. I knew it from the start. But I am wondering how to do it.

Thank you in advance for your help

Mario

I downloaded the Maple free trial but could not find the Migration Assistant. What to do?

In my Maple program, the voltage output of the system is computed as a time-domain response under different time intervals. The response curve has already been successfully obtained and plotted.

However, I would like to further extract and plot the envelope of this response. I initially attempted to determine the envelope by identifying the extrema of the signal, i.e., by solving the condition that the time derivative of the response equals zero. Unfortunately, this approach consistently leads to error messages, and I am not sure whether the issue is related to symbolic differentiation, numerical noise, or the implementation itself.

Could anyone please advise on:

1. The correct way to extract an envelope curve from a time-domain signal in Maple?

2. Whether there are alternative or more robust methods (e.g., based on numerical post-processing, signal processing techniques, or built-in Maple tools) to obtain the envelope, especially for numerically computed responses?

Any suggestions or example commands would be greatly appreciated.

Thank you in advance for your help.
numsolve-1229.mw