I compute the solution of this differential system

shock := piecewise(t <0, 0, t < 1, 10, 0):
sys   := {(M__p+M__a)*diff(x(t), t$2)=M__p*shock-x(t), x(0)=0, D(x)(0)=0}
sol   := unapply(rhs(dsolve(sys)), (M__p,M__a))

I'm interested in 3 quantities:

• the first time tend > 0 such that sol(tend) = 0,
• the time tmax in (0..tend) where sol(tmax) reaches its maximum value,
• the value xmax = sol(tmax).

Since sol has a relatively simple expression, I first attempted to use solve for calculating tend, but that didn't work.
The conclusion is still the same for tmax and xmax.

The values of these 3 quantities that I expect solve to provide, are those obtained using fsolve.

Can you explain me the failures I faced and show me how to force solve to get these values?
TIA

ToyProblem.mw

Let S be a set S={E1,E2,E3,E4,.....,Ek}  where E1 is a set of edges, E2 is another set of edges etc.

that like E1={{1,2},{2,3},..}, E2={{3,4},{1,2},....} , now we need to pick all possible  distinct sets of  size L  from the k sets of S such that the 

{E1,E2,E3,....,EL} are mutually disjoint with each other in other.

Ei intersect Ej is null no edge in common for i  not equal to j    where i, j varies from 1 to L.

F is the function which takes to parameters set S and L.

F(S,L)  then returns all possible sets which are such that {E1,E2,E3,....,EL} are mutually disjoint with each other in other.

Here mutually disjoint in graph theory terms they are edge-disjoint mutually 

I hava a recursive formula with variable n. The answer has the variable n and also N1.  What doe N1 mean?

Currrently maple exports it in huge fonts do the pdf is really big. I would like to make the pdf smaller by decreaseasing the font size. I cant seem to find any options for that online.

Hi ---

      I know how to add the Angstrom symbol to a plot's axis label using my mouse and the palette menu.  How can I add the Angstroms symbol programmatically to the plot command?  Thanks!

David

Hi

I want to solve two equations (Eqmin and Eqmax) numerically  and plot curves of Mmin and Mmax versus "sigma" in one frame, But the  second curve (Mmax) is not plotted !  What should I do? 
(We know that only real and positive roots are acceptable)
Eq.mw

I can not spawn draw the circles C3 and C4

restart;
with(plots):
with(geometry):
_EnvHorizontalName := x:
_EnvVerticalName := y:
R := 7:
point(A, [0, R]):
line(L1, y = sqrt(3)*x + R):
line(L2, y = -sqrt(3)*x + R):
line(L3, y = R/3):
intersection(B, L1, L3):
intersection(C, L2, L3):
detail(C):
triangle(ABC, [A, B, C]):
circle(C1, [point(P1, [0, 0]), R]):
circle(C2, [point(P2, [0, R/3 + (2*R)/9]), (2*R)/9]):
detail(C2):
center(C2), coordinates(center(C2)):
reflection(P3, P2, C):
detail(P3):
reflection(C3, C2, C);
detail(C3):
Error, (in geometry:-reflection) unable to compute coeff
Error, (in geometry:-detail) unknown object:  C3
circle(C3, [point(P3*[(28*sqrt(3))/9, 7/9]), (2*R)/9]):
Error, (in geometry:-point) wrong number of arguments
reflection(C4, C2, B);
detail(C4);
Error, (in geometry:-reflection) unable to compute coeff
Error, (in geometry:-detail) unknown object:  C4
circle(C3*[point(P3, [(28*sqrt(3))/9, 7/9]), (2*R)/9]);
Error, (in geometry:-circle) wrong number of arguments

draw([L1(color = blue), 
ABC(color = red, transparency = 0.5, filled = true), 
L2(color = blue), L3(color = blue), 
C1(color = blue, thickness = 3), C1(color = yellow, transparency = 0.8, filled = true), C2(color = blue, filled = true)], 
axes = normal,
 view = [-R .. R, -R .. R], 
scaling = constrained);
Why these error messages. Thank you veru much.

Respected sir,

It looks like the Maple function IsSubgraphIsomorphic(G1,G2) function I think it is developled from the

phyton networkx package function 

GraphMatcher.subgraph_is_isomorphic()   The source python code for this is in this link below

networkx.algorithms.isomorphism.ismags — NetworkX 2.8.6 documentation

Now Can considering the Graphs G1 and G2 as vertex labeled graphs can we tweek the function in such way that rather than just to return true based on shape The function will now take a new parameter extra

IsSubgraphIsomorphic(G1,G2,Label=True or False)

If Label= True the then the function will return true if their is a subgraph G1 isomorphic in G2 with the same type of labels exists then it returns true and also returns that graph G1 edges based on those labels in G2.

Can anyone help please your help will be acknolwedged surely

Intially let it be for the undirected graph cases only.

A "while" ago this was possible by commands. E.g.:

(from https://www.youtube.com/watch?v=uaQh_bXcIGA)

I consulted the help pages for Export and CodeGeneration options, but could not find anything suitable to generate a C code file.

Did I overlook something or searched for the wrong help pages?

If such options no longer exist, what is the preferred way to transfer C code from Maple to MapleSim?

Am I supposed to copy, paste & save with a third party editor? If I do so for a C code generated from a Maple procedure (generated with makeproc), I get

A complete example that works in 2022 versions would be helpfull. The tutorial "6.6 Tutorial 6: Using the External C Code/DLL Custom Component App" unfortuneately does not include code generated by Maple that can be imported, compiled, simulated and verified against a MapleSim model as in the example from youtube (which is still very instructive by the way). 

After loading the Physics package, I have define the langragian L this way:

L:=sqrt((1+(y')^2)/y)

After some algebra, I get the following integral:

((1+(y'(x))^2)^(-1)*1/y(x) = C

At that stage, I would like to isolate the term y'(x) and do the change of variable. But since I am under the Physics package, I try to isolate it with no succes and worst if I try to change the variable first. A little help would be appreciate.

Thank you in advance

Mario

Maple 2022 under Windows

Hello,

I have a nonlinear system of 12 SYMBOLIC equations in 6 variables. I am using solve() but it's taking me ages and will probably return the "Kernel connection has been lost" error after a half-day/ a day.

How do I solve it? Is it even possible to solve it? Is there a way to solve it approximately?

Thanks

Where is the problem within this procedure which I can not get the numerical values of V[1] , V[2], ...

Download ProcPropl.mw

fig([L1(color = blue), L2(color = blue), L3(color = green), C1(color = black), C2(color = black), C3(color = orange), C4(color = orange)]);
point(oo, [0, 0]);
                               oo

rotation(fig1, fig, oo, Pi/2, 'counterclockwise');
Error, (in geometry:-rotation) wrong type of arguments why thos error ? Thank you;
 

q := (f)->local ff := `if`(type(f,procedure),f,`x`->f); ff(z + (ff(k))):

Trying to create something so that I can do q(x) or q(x->x^2) or whatever.

Trying to understand the difference between an expression and a function as represented by maple. I thought I could just turn whatever is passed to q, such as x*cos(x) in to a function by x->x*cos(x) as one would do normally but this does not work.