hello dear maple maple users.

I'm trying to solve this system of equations using fsolve but i'm geting this unrealistic curve.

I don't know exactly how, can help me understand!!!!!.

fsolve.mw

I am working with the JetCalculus package along with the DifferentialGeometry package. Notation: if there are 2 independent variables (x,y), then u[1,2] would now represent the 3rd mixed partial derivative of u, once with respect to x and twice with respect to y. Please check Example 3 here, https://de.maplesoft.com/support/help/Maple/view.aspx?path=DifferentialGeometry/JetCalculus/TotalDiff

If I have an expression like u[1,0]+f(u[0,0])*u[0,1]+u[1,1]*u[0,3], then I am looking for a procedure which gives me the Lead derivative term. In the example above, it is u[1,1]*u[0,3], and then I can find the lead coefficient, i.e u[1,1].
Please note that the Lead derivative is not unique and can have several terms. For example, orders are the same for u[1,1] and u[0,2].

Idea: If I can find a way to extract the subscripts and do operations on them, then it would be very helpful. 
Any help/guidance is much appreciated. Thanks.
EDIT 1: LeadingDerivative command is not the solution for me.

Dear maple users,

A fine day wishes to all.

How to replace a value in already computed data value.

In my problem, I have evaluated a set of values (with help of #ma1 := evalf(seq((A4(t)), t = 0.0..1, 0.1));)  

ma1 := 0., .1941703021, .3203871063, .4089371834, .4712881303, .5145114133, .5435036431, .5617715009, .5718586242, .5756277760, .5744585726

I need to change 0 value as a 1.

I have used subs(ma[1]=1,ma1), but its coming wrong.

diff(w(r, theta), r)/r + diff(w(r, theta), r, r) + diff(w(r, theta), theta, theta)/r^2 = r^3*cos(3*theta)

Can it be solved without boundary conditions?

Hi there.

Following by https://www.mapleprimes.com/questions/232199-Bug-In-EllipticCPi

there is some strange behavior of EllipticPi - this function return complex answer when nu>1

WolframAlpha and some another online calculators return real values - just real part of Maple's value.

Why Maple's EllipticPi return complex answer?

help.mw

How to solve Linear first-order PDE by the Lagrange method?

dx/(x) =dy/0=dt/0=du/3=dv/v=dw/w, where x,y,t are independent variables and u,v,w are dependent variables.

hello guys,

I want to plot the phase plane between F and m when:

F := 736*R^4/sqrt((-1380*Pi*R*m(r)^3 + 368*R^4 - 1587*m(r)^2*R^2 + 1280*m(r)^2*a)^2);
R := X^(1/3)/(-l^2 + 4*a) - 3*l^2*m(r)^2/X^(1/3);
X := m(r)*l^2*(sqrt((27*l^2*m(r)^4 - 16*a^2*l^2 + 64*a^3)/(-l^2 + 4*a)) + 4*a)*(-l^2 + 4*a)^2;
 

and

m := (l^2*r^2 + r^4 + a*l^2)/(2*l^2*r)

for positive constant a and l

please guide me,

thanks

Hello everyone. I took part in a project in which we had to solve problems with Maple 2015. The managers gave us a permanent license. However recently I had trouble on my computer and now Maple doesn't work anymore because it somehow lost the license. The project ended last year, so I can't really ask them anymore. Is there any way to get the license working again? I checked on the site but didn't found anything useful and I'd really need it for the final exam of the last year of high school...

Thanks in advance!

Sorry file was not attached
 

Download CALC-0191-Upload.mw

When I have an operation to perform with Maple, my first reflex is to use the "native" Maple procedure(s) because it seems logical to think that they have been written in order to reduce the memory used and/or the execution time.
Unfortunately, this feeling is not confirmed by reading some of the answers provided on this site.

The attached file shows 4 ways (among probably several others) to center and reduce (by columns) a random matrix.
Amid them is the Statistics:-Scale procedure which appears not to be the most efficient (even a double loop outperforms in term of time).
This is just an example among many others (for instance Statistics:-Select can be easily outperformed)

So my question: why deceive the user with magic functions which sometimes have a very relative efficiency?

Scaling_efficiency.mw

Hello

I have used Maple almost daily for the last four years, but a few days ago two students approached me with an issue I had never encountered before. However, it had happened to both of them within a few weeks.

They described the issue as follows: When they opened a random Maple document and they tried to type in simple operators (like +, - or *), Maple would instead write an odd symbol, which none of them recognised as a mathematical symbol.

As they could not find a way to solve the problem within Maple, they tried restarting their computers. When they afterwards reopened Maple, the problem was gone and the operators worked as expected again. Neither of the students has experienced the issue since.

During the last few days, I have been trying to replicate the issue myself without success. Therefore, I also don't have any screenshots to share, so hopefully my simple explanation is enough.

My questions are: Has anyone heard about this issue before? Does anyone know what might have caused it? Is there a way to replicate it and/or prevent it from happening again in the future?

I hope someone is able to clarify it a bit for me! :)

Regards,

Frederik

How to find the location of the poles of a normal chord in an ellipse ?
Here is my code :

restart; with(geometry); with(plots); `local`(O);
_EnvHorizontalName := x; _EnvVerticalName := y;
corde := a*x/cos(theta)-b*y/sin(theta) = a^2-b^2;
isolate(corde, a/cos(theta));
Error, (in isolate) a*x/cos(theta)-b*y/sin(theta) = a^2-b^2 does not contain a/cos(theta)
eq1 := (a^2-b^2)*X/a^2 = a/cos(theta);
c := solve(eq1, cos(theta));
eq2 := (a^2-b^2)*Y/b^2 = -b/sin(theta);
s := solve(eq2, sin(theta));
lieu := simplify(expand((a^2-b^2)^2*X^2*Y^2*(c^2+s^2 = 1)));
allvalues(eliminate({eq1, eq2}, theta))[1][2];
ell := x^2/a^2+y^2/b^2 = 1;
P := [a*cos(theta), b*sin(theta)];
tgP := x*P[1]/a^2+y*P[2]/b^2 = 1;

sol := solve({corde, ell}, {x, y});
tgP1 := simplify(x*rhs(sol[2][1])/a^2+y*rhs(sol[2][2])/b^2 = 1);

Drawing in a case
a := 5; b := 3; theta := (1/6)*Pi;

line(l1, corde); conic(co, ell);
Pole(P1, l1, co); coordinates(P1);
a := 5; b := 3; theta := (1/6)*Pi;
Ell := implicitplot(ell, x = -a .. a, y = -b .. b, color = red);
Cor := implicitplot(corde, x = -a-1 .. a, y = -b-1 .. b, color = blue);
TgP := implicitplot(tgP, x = 0 .. 10, y = -5 .. 10, color = magenta);
TgP1 := implicitplot(tgP1, x = -5 .. 10, y = -5 .. 10, color = magenta);
lieu := subs(X = x, Y = y, lieu);
subs(x = 125*sqrt(3)*(1/24), y = -27/8, lieu);
Lieu := implicitplot(lieu, x = -a .. a, y = -b .. b, color = green);
dr := draw(P1);
display([Ell, Cor, Lieu, TgP, TgP1, dr], axes = normal, view = [-10 .. 10, -10 .. 10], scaling = constrained);

Why the drawin of the location (lieu) does not appear ? Thank you.

Hello,

For a quite long program, i have to use the Maple debugger. But, i have never used it before.

For a package containing subpackages like this :

Package 

    Subpackage1

         proc 1

         proc 2

     Subpackage 2

It seems that i have a mistake for one of procedure.

Consequently, for using the Maple debugger, i have tried this : 
with(package);
with(subpackage1);
stopat(proc 1) 

But, it does nothing.

May you explain me how i can use the Maple debugger in a package ?

I find in the web this vidéo : https://www.youtube.com/watch?v=cUVbMOTQzRA

It describes how to use the Maple debugger but only on a very short procedure and not in a package.

I thank you in advance for your help and tips

Hi there.

It seems like EllipticCPi(n,k) has a bug when n close to 1:

Both answers should be equal by definition and first is true.

ell_error.mw

I have the following program in Maple:

with(plots);
my_array := [[.1, .1], [.3, .45], [.55, .78], [.8, .9]]; #define an array of points
my_graph := pointplot(my_array, connect = true); #plot the array on a graph, connecting points
line := plot(.7, x = 0 .. 1); #plotting a horizontal line
display(my_graph, line); #displaying on the same graph

The output looks as follows:

I want to add a vertical line corresponding to the intersection of these two lines. Is there a way to do it?