MaplePrimes - Maple 2021 Posts and Questions

Why does GUI execution hang?

JP Howe — Sun, 16 Nov 2025 18:08:14 Z

It hangs are v(x) := for some reason.

NULL;

q := x -> v1*Dirac(x - a1) + v2*Dirac(x - a2) + v3*Dirac(x - a3);
NULL;

V := x -> -int(q(x), x = 0 .. x) + Ra + Rb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

:-`+`(Units:-Simple:-`+`(Units:-Simple:-`-`(MTM:-int(q(x), x

= 0 .. x)), Ra), Units:-Simple:-`*`(Rb, Dirac(Units:-Simple:-\

`+`(x, `-`(L))))) end proc

NULL;

M := x -> int(V(x), x = 0 .. x) + Ma + Mb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

:-`+`(Units:-Simple:-`+`(MTM:-int(V(x), x = 0 .. x), Ma),

Units:-Simple:-`*`(Mb, Dirac(Units:-Simple:-`+`(x,

`-`(L))))) end proc

theta := x -> 1000000000000*(int(M(x), x = 0 .. x) + `θa` + `θb`*Dirac(x - L))/(E*S_mm);
proc (x) options operator, arrow, function_assign; Units:-Simple\

:-`*`(Units:-Simple:-`+`(Units:-Simple:-`+`(MTM:-int(M(x), x

= 0 .. x), `θa`), Units:-Simple:-`*`(`θb`,

Dirac(Units:-Simple:-`+`(x, `-`(L))))), 1/(E*S_mm*10^(-12)))

end proc

v := x -> int(theta(x), x = 0 .. x);
proc (x) options operator, arrow, function_assign; MTM:-int(thet\

a(x), x = 0 .. x) end proc

The logarithmic equation

MichaelVio — Sun, 02 Nov 2025 17:44:37 Z

Please advise. I have a logarithmic equation.

E(ν)=E0·ln(1+2·A·ν)+Em+C·ν^2

With constant E0>0, Em<0, C<0 and A>0, and E(ν) of variable ν between [10^4 and 10^13]

I have 3 points, ν1, ν2, and ν3, and the value of the function E(ν) at each point. I want to choose A to obtain the smallest absolute value of Em, preferably ~ -0.00005. The value of ν1, ν2, ν3 and E(ν1), E(ν2), E(ν3) are known.

With what “A” should I start to obtain Em~ -0.00005?

restart;

>	Digits:=25;

(1)

>	E(nu):=Em+E0ln(1+A3.765333333333333333310^(-18)nu)+ C*nu^2;

(2)

>	E1:=subs(nu=5.754173859*10^8,E(nu));

(3)

>	E2:=subs(nu=6.338671958*10^8,E(nu));

(4)

>	E3:=subs(nu=31*10^9,E(nu));

(5)

>	solve({E1=3.259,E2=3.59});

(6)

>	sol:=solve({E1=3.259,E2=3.59,E3=0},{Em,E0,C,A});

(7)

>	A:=4.19747*10^6;evalf(sol[4]);#Em

(8)

>	Em:=-0.07291335370248713771647314;

(9)

>	evalf(sol[3]);#E0

(10)

>	E0:=373.7014139352964920547905;

(11)

>	evalf(sol[2]);#C

(12)

>	C:=-1.549823289304468027271168*10^(-19);

(13)

>	E(nu):=Em+E0ln(1+A3.765333333333333333310^(-18)nu)+ C*nu^2;

(14)

>	plot(E(nu),nu=10^6..3.1*10^10);

>	evalf(subs(nu=5.75417385910^8,E(nu)));evalf(subs(nu=6.33867195810^8,E(nu)));evalf(subs(nu=6.974105195*10^8,E(nu)));

(15)

>	evalf(subs(nu=0,E(nu)));evalf(subs(nu=11.410^6,E(nu)));evalf(subs(nu=15.910^9,E(nu)));#44.5eV @ 15.9Ghz

(16)

Download ML.mw

solve ode equations plot solution

MichaelVio — Sun, 12 Oct 2025 16:05:08 Z

I want to solve differential equations using dsolve and plot the solution in the range plot(E(nu), nu=10^14…10^18) of the equation.

restart;

>	with(PDEtools, dchange):

>	N:=8PiTq^2nu^2E(nu)/(c^3(exp(E(nu)/(kT)) - 1));V:=Pi*rb^3;

(1)

>	Et:=dchange({nu=1/t},N*V,expand);#Change of var in t = period of a single oscilation;

(2)

>	Sol_T:=subs(t=t,(Et)-subs(t=t+Tq,(Et)));#We do the calculus per one period Tq;

(3)

>	Sol_nu:= dchange({t=1/nu},Sol_T,params=Tq,expand);# I like to go back to variable nu but is correct???;

(4)

>	B:=int(diff(Sol_nu,nu),t=t..t+Tq);

(5)

>	dsolve(Sol_nu=A*B,E(nu));#Where A = constant

(6)

>	E(nu):=solve(E(nu)=-nu + ATqln(Tqnu + 2) + 3ATqln(nu) - 2ATqln(Tqnu + 1) - ATqln(exp(E(nu)/(kT)) - 1) + ATq*ln(E(nu))+C1,E(nu));

(7)

>	#E(nu)=???

>	k:= 1.380649000010^(-23);rb:=5.29310^(-11); ec:= 1.60217663410^(-19);Tq:=1.76510^(-19); c:= 299792458;T:=297;A:=1;

(8)

>	plot(-nu - 2ATqln(Tqnu + 1) + 3ATqln(nu) + ATqln(Tqnu + 2),nu=10^14..10^18);#Approx neglecting => -ATqln(exp(E(nu)/(kT)) - 1) + ATq*ln(E(nu))

>	plot(E(nu),nu=10^14..10^18);

Warning, expecting only range variable nu in expression ln(exp(RootOf(-A*Tq*ln(nu^3/(Tq*nu+1)^2*(Tq*nu+2)*ln(exp(_Z)+1)*T*k)+_Z*A*Tq+ln(exp(_Z)+1)*T*k-C1+nu))+1)*T*k to be plotted but found names [A, C1, T, Tq, k]

Download plm.mw

Plotting problem

MichaelVio — Wed, 19 Mar 2025 18:56:41 Z

Hi everyone,

I'm having some trouble with plotting in Maple and was hoping to get some help here. I'm trying to create a plot for a specific function, but I'm not sure if I'm using the right commands or parameters. Here’s what I’m trying to do:

To plot the line plot(E3,nu=10^13..4.5*10^18);

and

plot(E1(nu),nu=10^13..4.5*10^18);

you can look around my calculus please advise.

Could someone please explain what might be going wrong with my approach? Any suggestions or examples of correct usage would be greatly appreciated.

Thanks in advance for your help!PLanckPh.mw

performance of simple procedure

SFMACOME — Thu, 06 Mar 2025 09:26:57 Z

Dear team,

Here below you can see a simple program containing 3 loops. The problem is that even for low iterations the execution time seems endless. I kept this program running for over 10 minutes to no avail. Could you help me?

Here you are the technical details of my HP laptopper

How to adjust the program so that the animation works

JAMET — Tue, 11 Feb 2025 15:55:40 Z

restart;
Fig:=proc(t)
local a,b,c,A,B,C,Oo,P,NorA,NorB,NorC,lieu,Lieu,dr,tx:
uses plots, geometry;
a := 11:b := 7:
c := sqrt(a^2 - b^2):

point(A, a*cos(t), b*sin(t)):
point(B, a*cos(t + 2/3*Pi), b*sin(t + 2/3*Pi)):
point(C, a*cos(t + 4/3*Pi), b*sin(t + 4/3*Pi)):
point(Oo,0,0):
lieu:=a^2*x^2+b^2*y^2-c^4/4=0:
Lieu := implicitplot(lieu, x = -a .. a, y = -b .. b, color = green):

line(NorA, y-coordinates(A)[2] =((a^2*coordinates(A)[2])/(b^2*coordinates(A)[1]))*(x-coordinates(A)[1]),[x, y]):
line(NorB, y-coordinates(B)[2] =((a^2*coordinates(B)[2])/(b^2*coordinates(B)[1]))*(x-coordinates(B)[1]), [x, y]):
line(NorC, y-coordinates(C)[2] =((a^2*coordinates(C)[2])/(b^2*coordinates(C)[1]))*(x-coordinates(C)[1]),[x, y]):
intersection(P,NorA,NorB):

ellipse(p, x^2/a^2 + y^2/b^2 - 1, [x, y]);

tx := textplot([[coordinates(A1)[], "A"],[coordinates(A2)[], "B"], [coordinates(C)[], "C"], [coordinates(Oo)[], "O"],#[coordinates(P)[], "P"]], font = [times, bold, 16], align = [above, left]):
dr := draw([p(color = blue),NorA(color=red,NorB(color=red),NorC(color=red),p(color=blue),
Oo(color = black, symbol = solidcircle, symbolsize = 8), P(color = black, symbol = solidcircle, symbolsize = 8)]):
display(dr,tx,Lieu,scaling=constrained, axes=none,title = "Les triangles inscrits dans une ellipse ont leur centre de gravité en son centre . Lieu du point de concours des perpendicalaires issues des sommets", titlefont = [HELVETICA, 14]);
end:

Error, `:=` unexpected
plots:-animate(Fig, [t], t=0.1..2*Pi, frames=150);