Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

When executing DEBUG within inline code (not within a procedure) the values displayed in successive debug windows (on clicking continue) are added to the end of my worksheet. How can the latter display be prevented?

Hello,

is it possible to solve the attached partial differential equation with zero initial boundary condition?

If not by assuming diff(u(sigma, tau, phi, t), t, t)=0 is there an answer for the equation?

Thanks

lapla.mw

Suppose two following Eqs.:

(1) du/dt+d(u*w)/dx=0

(2) dw/dt+wdw/dx=0

I want to expand u(x,t) and w(x,t) in the power series of epsilon

u=u0+epsilon*u1+epsilon^2*u2+…

w=w0+epsilon*w1+epsilon^2*w2+…

and change the variables x,t to X,T as follows

 X=(x-alpha*t) and T=beta*t,

and solving Eqs. (1) and (2) for different order of epsilon (epsilon, epsilon^2, epsilon^3,…) to finding u0,w0,u1,w1,…

How do I do that?

Thanks.

 

Maple 2020 offers many improvements motivated and driven by our users.

Maple 2018  has recently has  become sluggish to start up  -and very slow to respond to input. Can anyone suggest remedies?  I have plenty of space and CPU. Other apps seem to start fine.  Can any suggest a diagnosis and/or solution?

Melvin

Maple Tutors allow for copying of MathML but I need LaTeX of it. Any help please?

If we have an equation for the generalized Bloch sphere i.e.,

\partial_{t}(u^{2} + v^{2} + w^{2}) = 0,

where u, v and w are functions of x and t and the initial conditions u=v=0, w=-1. Then how to plot this equation on maple?

Being an absolut newbie to Maple I find some of the functions a bit strange and difficult.

One of the things is e.g. rounding numbers.

In Pyton and other languages it is quite simple and straightforward when rounding a number.

round(number, digits)

If you have digits = 0 then you get an integer, otherwise you get a number with the number of digits chosen.

In Maple the round function is just for rounding to an integer.

To round to something else currently I don't really know what I would use. There is the evalf function, which one can use like evalf[digits](number), but that doesn't give you the value with digits. It gives you a number with significant digits, which means, also including the numbers before the comma delimiter.

Python
round(15.76543,2) = 15.77

Maple
evalf[2](15.76543) = 16

Wouldn't it be much easier to expand the functionality of the round function in Maple?

 

 

"Frame your math" does not work on a new iPhone XS; however, surprisingly, it work just fine on an old iPad (4th gen).

I am logged in. The app has access to the camera. The companion app does allow manual entry of equation to upload to the Maple cloud.

I expect it's something simple--like some sort of permissions setting, but I cannot find it . . .

 

BTW: The error is "The request timed out. Check your Internet connection."

Noticed an issue with Vector and excel.  Not even really excel but I found it through that.  

If I select a row in excel and do a copy paste into Maple it sometimes appears as if it's a list.  ie it shows up as [1,2,3,4]  other times it shows up as [ 1 2 3 4 ] signifying an array (for this example I've saved as the data under the variable a).  Running whattype(a) on the data shows they're both arrays.  Of course it's probably wise to instead load data through Excel into Maple by using the ExcelTools and Import option, however I didn't think there was no reason to use the copy paste option.  It does, to some extent, or maybe, well, it shows a limitation.

In the first instance when it shows up as a list, I thought it might be simple enough just to add other numbers in the list ie/ just tack on ,5,6,7,8 after the 4.  But after pressing enter we get the error

Error, invalid sequence

I don't understand why I couldn't just add to the copied data but maybe it's the formatting of the data that was pasted into maple? 

With the original copied data, I can use with(plots):  listplot(a) no problem however, we want to add data.  ArrayTools will let us Append data to the vector

with(plots):
with(ArrayTools):
Append(a,5,6,7,8)

listplot(a) # will throw another error

                  Error, (in plots:-pointplot) points cannot be converted to floating-point values (this doesn't show in Maple 2019 but does come up in Maple 18)

For Maple 2019 it with responds with a returned array [ 1 2 3 4 5,6,7,8]

Running listplot on that Appended Array.  Maple only recognizes the next 1 added value.

So this means appending values using ArrayTools and Append only allows us to append one value at a time?  Is that a bug?  Are there better ways to append values to vectors?  The only solution for that is to convert to a list and use op to append more values.  But perhaps Maple should have understood the copied values from Excel should have been a list or listlist of values?

 

 

 

Hompotopy perturbation method

restart; with(LinearAlgebra);
PDEtools[declare](f(x), prime = x);
PDEtools[declare](g(x), prime = x);
N := 3;
F := sum(p^i*f[i](x), i = 0 .. N);
G := sum(p^i*g[i](x), i = 0 .. N);
FEq := (1-p)*(diff(F, x$3))+p*(diff(F, x$3)-(2*(diff(F, x$1))*(diff(F, x$1))-(5/2*F)*(diff(F, x$2))+M*(diff(F, x$1))) . A);
GEq := (1-p)*(diff(G, x$2))+p*(diff(G, x$2)+(5/2*(1/(1+R)) . Pr)*F*(diff(G, x$1)))*K(L);

M := 1;
A := (((1-W)^2.5*(1-W))*`ρf`+W*`ρt`)/`ρf`;
Pr := 6.2;
K := ((1-W)*`ρf`*Cf+W*`ρt`*Cs)/`ρf`;
L := .5;
`ρf` := 998.3;
`ρt` := 3970;
W := .2;
R := 1.0;
Cs := 765;
Cf := 4182;
coeff(FEq, p, 0);
coeff(GEq, p, 0);
for i from 0 to N do Fequ[i] := coeff(FEq, p, i) = 0 end do;
for i from 0 to N do Gequ[i] := coeff(GEq, p, i) = 0 end do;
Fcond[1][0] := f[0](0) = 0, (D(f[0]))(0) = 1, (D(f[0]))(5) = 0; for j to N do Fcond[1][j] := f[j](0) = 0, (D(f[j]))(0) = 0, (D(f[j]))(5) = 0 end do;
Gcond[0] := g[0](0) = 1, g[0](5) = 0; for j to N do Gcond[j] := g[j](0) = 0, g[j](5) = 0 end do;

for i from 0 to N do dsolve({Fequ[i], Fcond[1][i]}, f[i](x)); f[i](x) := rhs(%) end do;
for i from 0 to N do dsolve({Gcond[i], Gequ[i]}, g[i](x)); g[i](x) := rhs(%) end do;
Fa := simplify(sum(f[n](x), n = 0 .. N)); dFa := diff(Fa, x); subs(x = 2.4, dFa);
Ga := simplify(sum(g[n](x), n = 0 .. N)); dGa := diff(Ga, x); subs(x = 2.4, dGa);
plot(Ga, x = 0 .. 5);
plot(dFa, x = 0 .. 5);

ND sove solution 

Eq1 := diff(F(x), x$3)-(2*(diff(F(x), x$1))*(diff(F(x), x$1))-(5/2*F(x))*(diff(F(x), x$2))+M*(diff(F(x), x$1))) . A = 0;
Eq2 := (diff(G(x), x$2)+(5/2*(1/(1+R)))*Pr*F(x)*(diff(G(x), x$1)))*K(L) = 0;
M := 1;
Pr := 6.2;
A := (((1-W)^2.5*(1-W))*`ρf`+W*`ρt`)/`ρf`;
K := ((1-W)*`ρf`*Cf+W*`ρt`*Cs)/`ρf`;
L := 1;
`ρf` := 998.3;
`ρt` := 3970;
W := .2;
R := 2.0;
Cs := 765;
Cf := 4182;

Cd1 := F(0) = 0, (D(F))(0) = 1, (D(F))(5) = 0;
dsys := {Cd1, Eq1};
dsol := dsolve(dsys, numeric, output = operator);
dsol(.1);
plots[odeplot](dsol, [x, diff(F(x), x$1)], 0 .. 5, color = green);
Cd2 := G(0) = 1, G(5) = 0;
dsys := {Cd1, Cd2, Eq1, Eq2};
dsol := dsolve(dsys, numeric, output = operator);
plots[odeplot](dsol, [x, G(x)], 0 .. 5, color = green)

 

I find some book teach motion planning in topology 

but do it need to formulate the equations for the environments such as a map with obstacle in 2d or 3D?  the environment is quite complex, how can these equations be formulated?

 

how do i Import part or all  PDF files into maple 

I believe this was easier in older versions of maple or worked partially.

How I can pdsolve these equations in toroidal coordinates?

Initial conditions are arbitrary.

Please see attached pdf .

Thanks

Where.pdf

Weston1958

Can old maple version saved .m files in window be readable in maple 2015 Linux version?

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