MaplePrimes Questions

I was about to verify two solutions of dsolve from here but could not find an agreement for negative values. This makes me wonder if all values are computed.

There is also a different behaviour that I do not understand when allvalues is given a RootOf expression or an equation containing a RootOf expression.
 

dsolve without method

ode:=diff(y(x), x) = (3*x - y(x) + 1)/(3*y(x) - x + 5);
ic:=y(0)=0;
dsolve({ode,ic});
plot(rhs(%),x=-10..10,numpoints=10);
evalf(subs(x=3,%%));
evalf(subs(x=-3,%%%));

diff(y(x), x) = (3*x-y(x)+1)/(3*y(x)-x+5)

 

y(0) = 0

 

y(x) = -(-(1/36)*(x+1)^2*((-324+12*(96*x^3+288*x^2+288*x+825)^(1/2))^(2/3)-24*x-24)^2/(-324+12*(96*x^3+288*x^2+288*x+825)^(1/2))^(2/3)-x^3-x^2+x+1)/(x+1)^2

 

 

y(3) = 2.135964164

 

y(-3) = -2.302775638+0.4883358175e-9*I

(1)

dsolve with a particular method

sol:=dsolve([ode,ic],[dAlembert]);
odetest(sol,[ode,ic]);

y(x) = RootOf(-6*((x+_Z+3)/(5+3*_Z-x))^(2/3)*(-4*(-x+_Z+1)/(5+3*_Z-x))^(1/3)*_Z+2*((x+_Z+3)/(5+3*_Z-x))^(2/3)*(-4*(-x+_Z+1)/(5+3*_Z-x))^(1/3)*x+2*(-4)^(1/3)*3^(2/3)-10*((x+_Z+3)/(5+3*_Z-x))^(2/3)*(-4*(-x+_Z+1)/(5+3*_Z-x))^(1/3))

 

[0, 0]

(2)

Since allvalues fails on this expression for real valued x, rational and integer values are tried for punctual comaprision

subs(x=3,sol);
allvalues(%);
evalf(%)

y(3) = RootOf(-6*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)*_Z-4*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)+2*(-4)^(1/3)*3^(2/3))

 

y(3) = (6873/256)*(-(4/6873)*(20994724+82476*6873^(1/2))^(1/3)-(128/3)/(20994724+82476*6873^(1/2))^(1/3)+1/3-((1/2)*I)*3^(1/2)*((8/6873)*(20994724+82476*6873^(1/2))^(1/3)-(256/3)/(20994724+82476*6873^(1/2))^(1/3)))^2+(1/96)*(20994724+82476*6873^(1/2))^(1/3)+(2291/3)/(20994724+82476*6873^(1/2))^(1/3)-8947/768+((2291/256)*I)*3^(1/2)*((8/6873)*(20994724+82476*6873^(1/2))^(1/3)-(256/3)/(20994724+82476*6873^(1/2))^(1/3)), y(3) = (6873/256)*((8/6873)*(20994724+82476*6873^(1/2))^(1/3)+(256/3)/(20994724+82476*6873^(1/2))^(1/3)+1/3)^2-(1/48)*(20994724+82476*6873^(1/2))^(1/3)-(4582/3)/(20994724+82476*6873^(1/2))^(1/3)-8947/768, y(3) = (6873/256)*((8/6873)*(20994724+82476*6873^(1/2))^(1/3)+(256/3)/(20994724+82476*6873^(1/2))^(1/3)+1/3)^2-(1/48)*(20994724+82476*6873^(1/2))^(1/3)-(4582/3)/(20994724+82476*6873^(1/2))^(1/3)-8947/768

 

y(3) = -6.067982077+1.049560864*I, y(3) = 2.13596417, y(3) = 2.13596417

(3)

Two roots match the dsolve solution without method. However doing the same only on the right hand side produces different output. For some reason allvalues produces 3 RootOf expressions with a numerical root selector.

subs(x=3,rhs(sol));
allvalues(%);
evalf(%)

RootOf(-6*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)*_Z-4*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)+2*(-4)^(1/3)*3^(2/3))

 

RootOf((3*I)*3^(1/6)*2^(2/3)+2^(2/3)*3^(2/3)-6*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)*_Z-4*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3), -6.067982082+1.049560860*I), RootOf((3*I)*3^(1/6)*2^(2/3)+2^(2/3)*3^(2/3)-6*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)*_Z-4*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3), 2.135964164), RootOf((3*I)*3^(1/6)*2^(2/3)+2^(2/3)*3^(2/3)-6*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3)*_Z-4*((6+_Z)/(2+3*_Z))^(2/3)*(-4*(-2+_Z)/(2+3*_Z))^(1/3), 2.135964164-0.*I)

 

-6.067982082+1.049560860*I, 2.135964164, -6.067982082+1.049560860*I

(4)

Why this change?
Now the same with a negative value. Now the root does not match the solution of the dsolve call without method.

subs(x=-3,sol);
allvalues(%);
evalf(%)

y(-3) = RootOf(-6*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3)*_Z-16*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3)+2*(-4)^(1/3)*3^(2/3))

 

y(-3) = -1/2+(1/2)*13^(1/2)

 

y(-3) = 1.302775638

(5)

subs(x = -3, rhs(sol));
allvalues(%);
evalf(%);

RootOf(-6*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3)*_Z-16*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3)+2*(-4)^(1/3)*3^(2/3))

 

RootOf((3*I)*3^(1/6)*2^(2/3)-6*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3)*_Z+2^(2/3)*3^(2/3)-16*(_Z/(8+3*_Z))^(2/3)*(-4*(4+_Z)/(8+3*_Z))^(1/3), 1.302775638+0.*I)

 

1.302775638

(6)

NULL

 

NULL


 

Download allvalues.mw

I gave up trying to figure out why Maple sometimes generates solutions from my code that look different, running the same exact code. I know Maple is not deterministic and this can happen sometimes for reasons I will never know.

The following two solutions are the same, it just sometimes Maple shuffles terms a little around. For example SQRT(6) comes out SQRT(2)*SQRT(3).  I have no idea why this happens. It could be how memory inside Maple happened to be at the time and what happened before.

But my question is the following. Here is one ode, and two solutions that are exactly the same. I called one good_sol and one bad_sol.

If I do simplify(bad_sol - good_sol) I get  0 = 0 but here is the problem. When calling odetest on the good_sol, Maple returns 0 instantly,  But on the bad_sol it just hangs.

Even though the two solution are exactly the same. i.e. Mathematically the same.  

I'd like to know why does this happen? And if there is a permanent fix I could always use.

The following worksheet shows this problem.

After much trial and error, I found that if I do radnormal(bad_sol) then now odetest returns zero right away and the hang is gone!

I am just trying to understand why. And why odetest then itself does not use radnormal if this makes it work better?

Do I need to call randormal on every solution before calling odetest then? Will calling randormal on the final solution have any bad side effects on other computation after that?  It should not I would think.

This is all done in code without looking at the screen and having to decide. So I would need a solution that will work for all cases. But for now, I will change my code and add randormal to all solutions and see what happens.

Using 2024.1 on windows.   May be Maple behaves different on macOS, I do not know.

interface(version);

`Standard Worksheet Interface, Maple 2024.1, Windows 10, June 25 2024 Build ID 1835466`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1767 and is the same as the version installed in this computer, created 2024, June 28, 12:19 hours Pacific Time.`

restart;

ode:=4*x*diff(y(x),x)^2-3*y(x)*diff(y(x),x)+3 = 0;

4*x*(diff(y(x), x))^2-3*y(x)*(diff(y(x), x))+3 = 0

bad_sol:=ln(x) - c__1 - 1/2*ln((y(x)^2 - 6*x)/x) - 3*ln((sqrt(3)*y(x) + sqrt((3*y(x)^2 - 16*x)/x)*sqrt(x))/sqrt(x)) + 1/2*arctanh(1/2*(-16*sqrt(x) + 3*y(x)*sqrt(2)*sqrt(3))*sqrt(2)/(sqrt((3*y(x)^2 - 16*x)/x)*sqrt(x))) + 1/2*arctanh(1/2*(16*sqrt(x) + 3*y(x)*sqrt(2)*sqrt(3))*sqrt(2)/(sqrt((3*y(x)^2 - 16*x)/x)*sqrt(x))) = 0;

ln(x)-c__1-(1/2)*ln((y(x)^2-6*x)/x)-3*ln((3^(1/2)*y(x)+((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2))/x^(1/2))+(1/2)*arctanh((1/2)*(-16*x^(1/2)+3*y(x)*2^(1/2)*3^(1/2))*2^(1/2)/(((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2)))+(1/2)*arctanh((1/2)*(16*x^(1/2)+3*y(x)*2^(1/2)*3^(1/2))*2^(1/2)/(((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2))) = 0

good_sol:=ln(x) - c__1 - 1/2*ln((y(x)^2 - 6*x)/x) - 3*ln((sqrt(3)*y(x) + sqrt(x)*sqrt((3*y(x)^2 - 16*x)/x))/sqrt(x)) + 1/12*sqrt(3)*sqrt(6)*sqrt(2)*arctanh(1/2*(-16*sqrt(x) + 3*y(x)*sqrt(6))*sqrt(2)/(sqrt(x)*sqrt((3*y(x)^2 - 16*x)/x))) + 1/12*sqrt(3)*arctanh(1/2*(16*sqrt(x) + 3*y(x)*sqrt(6))*sqrt(2)/(sqrt(x)*sqrt((3*y(x)^2 - 16*x)/x)))*sqrt(6)*sqrt(2) = 0;
 

ln(x)-c__1-(1/2)*ln((y(x)^2-6*x)/x)-3*ln((3^(1/2)*y(x)+((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2))/x^(1/2))+(1/12)*3^(1/2)*6^(1/2)*2^(1/2)*arctanh((1/2)*(-16*x^(1/2)+3*y(x)*6^(1/2))*2^(1/2)/(((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2)))+(1/12)*3^(1/2)*arctanh((1/2)*(16*x^(1/2)+3*y(x)*6^(1/2))*2^(1/2)/(((3*y(x)^2-16*x)/x)^(1/2)*x^(1/2)))*6^(1/2)*2^(1/2) = 0

simplify(bad_sol-good_sol)

0 = 0

odetest(good_sol,ode); #instant answer

0

odetest(bad_sol,ode); #hangs

Warning,  computation interrupted

 

radnormal(bad_sol)

ln(x)-c__1-(1/2)*ln((y(x)^2-6*x)/x)-3*ln((y(x)*x^(1/2)*3^(1/2)+x*(-(-3*y(x)^2+16*x)/x)^(1/2))/x)+(1/2)*arctanh((-(-3*y(x)^2+16*x)/x)^(1/2)*(3*y(x)*x^(1/2)*3^(1/2)-8*2^(1/2)*x)/(3*y(x)^2-16*x))+(1/2)*arctanh((-(-3*y(x)^2+16*x)/x)^(1/2)*(3*y(x)*x^(1/2)*3^(1/2)+8*2^(1/2)*x)/(3*y(x)^2-16*x)) = 0

odetest(%,ode); #instant answer

0

 


 

Download why_same_sol_hangs_july_7_2024.mw

 

Why  does it appear  floating-point values?

restart;
with(plots);
with(geometry);
_EnvHorizontalName := 'x';
_EnvVerticalName := 'y';
xA := 5;
yA := 0;
point(A, xA, yA);
xB := 5;
yB := -7;
point(B, xB, yB);
midpoint(C, A, B);
segment(sg1, A, B);
xP := -12;
yP := 0;
point(P, xP, yP);
PerpenBisector(L, C, P);
line(YYp, y = yB);
line(XXp, y = 0);
intersection(M, L, YYp);
line(PM, [P, M]);
projection(H, C, PM);
triangle(CMP, [C, M, P]);
triangle(ABH, [A, B, H]);
distance(B, H);
circle(cir, [B, 7]);
display(textplot([[coordinates(A)[], "A"], [coordinates(B)[], "B "], [coordinates(C)[], "C"], [coordinates(M)[], "M"], [coordinates(H)[], "H"], [coordinates(P)[], "P"]], align = {"above", 'right'}),
draw([YYp(color = red), XXp(color = black), PM(color = green), L(color = green), sg1(color = black), cir(color = magenta), P(color = black, symbol = solidcircle, symbolsize = 10), M(color = black, symbol = solidcircle, symbolsize = 10), H(color = black, symbol = solidcircle, symbolsize = 10), A(color = blue, symbol = solidcircle, symbolsize = 10), B(color = blue, symbol = solidcircle, symbolsize = 10), CMP(color = blue, filled = true, transparency = 0.8), ABH(color = red, filled = true, transparency = 0.8), C(color = blue, symbol = solidcircle, symbolsize = 10)]),
axes = none, view = [-15 .. 14, -15 .. 3]);
I want to change this figure when xP varies from -12 to 12; Is it possible to use Explore or animate ? Thank you.

Is there a way to apply Intc() and Fundiff() in spherical coordinates? If I initialize a spherical coordinate system X and then want to calculate the effect with Intc(), r, theta phi and t are integrated from -inf to inf but  thtea:(0, pi) phi:(0, 2Pi). I would also need a second spherical coordinate system Y, if I have understood Fundiff() correctly, but how can I define this Coordinates(X = spherical, Y = spherical) does not work.  

I would like to vary my Lagrange density (16) with respect to f_A(r). Where r is the radial coordinate of the spherical coordinate system.

YANG-MILLS-Theorie.mw

Dear maple user,for defining the piecewise function please rectify this

h:z-> piecewise(do+Lo<z<do+4*Lo+0.3,    1-cos(2*pi*(z-L), other wise 1)

Hi all guys, I don't know how to simplify this easy expression? I have tried simplify command, and expand command, no use. Welcome to answer and thank you!

 

y1(x) = 2*sin(x)-sin(2*x)+cos(2*x); y2(x) = 4*sin(x)+sin(2*x)-cos(2*x); diff(y1(x), x); diff(y1(x), x); simplify*(1/2*((diff(y1(x), x))^2+(diff(y2(x), x))^2)+1/2*(3*y1(x)^2-y1(x)*y2(x)+y2(x)^2))

simplify*((1/2)*(diff(y1(x), x))^2+(1/2)*(diff(y2(x), x))^2+(3/2)*y1(x)^2-(1/2)*y1(x)*y2(x)+(1/2)*y2(x)^2)

(1)

 

Download simplify_expression.mw

I have four symmetries as

1] \frac{\partial}{\partial t)

2] \frac{\partial}{\partial x)

3] \frac{\partial}{\partial y)

4] 2t \frac{\partial}{\partial t)+x\frac{\partial}{\partial x)+y\frac{\partial}{\partial y)-2u\frac{\partial}{\partial u)

Kindly help me out to find 1D optimal system with structural constants.

I will be greatful.

There exists a new (?) checkbox  in the Interface tab of the Options dialog: 

But I cannot find any find any explanation about it in the corresponding help page. What is the purpose of this feature? 

I have a Dataframe of data, although I assume this question applies to any type of rTable-like structure.

What is a simple/elegant way to export the image of the data to a JPG file?  I would be happy to see it in the format when I ask it to print the Dataframe, or when I use DocumentTools:-Tabulate.

I have created two graphs*, each is a combination of multiple plots. From this, I use "plots:-display" to create an array of the two graphs.  I wish to export this array of graphs to a jpg file. Is this possible?  (Yes, I can export each graph, but I would like it combined in the array image that Maple displays.)

* Why the asterisk: I make two plots. When I combine them through the plots:-display procedure, what type of output is produced? I've called it a graph. The help implies the output is a plot array. However, that is different from displaying an array of graphs through plots: display (Array([plot1, plot2])). Correct?

i have made a full working code for differential quadrature method now i am  changing examples and it is not working although i have properly defined new parameters i am attaching my code kindly help me out
one more thing one example include summation n=0..ininity it is not even evaluating taking alot of time i am attaching both codes kindly help me out
A+B_example.mw
chelishkov_comparison.mw

Is there a way to install 2024.1 and keep 2024 there also? i.e. install 2024.1 along side 2024? This way if I find a problem and want to check 2024 I still have it? 

i.e. install Maple 2024.1 in its own folder, separate from Maple 2024, and have its own icon on desktop. 

If I install 2024.1 using Tools->Check for update,  it will overwrite 2024 and not ask me if I want to keep it. At least this is what happened in Maple 2023 and earlier versions. So wanted to ask before I try to do this again, else it will be too late.

If I do not use Tools->Check for updates, and instead download 2024.1 manually from the product web page, will one then be able to install 2024.1 and keep 2024? Or will it also overwrite 2024? I have not tried because I do not know if it will ask me or not.

Maple 2024.

Dear all, in Maple Help exists the documentation of how to use the OpenMaple API Library. But I didn't found a link where to download the necessary libraries. I found e.g. the library maple-0.17.4.jar but it doesn't contain com.maplesoft.openmaple.*

http://www.java2s.com/example/jar/m/maple-index.html

Tahnks for help

Circular_gears_meshing_blunt_teeth_shape_from_involute_of_circle.mw

My worksheet has suddenly begun producing the following error message when executing legitimate commands:

Error, (in cos) type `SymbolicInfinity` does not exist

Why has this worksheet suddenly begun issuing these mysterious error messages and how can it be restored to working order?

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