1.

similar gap system, which function can output coset table ?

if find example below,

f := FreeGroup( "a", "b" );

g := f / [f.1^2, f.2^3, (f.1*f.2)^5];
tab := CosetTable(g, Subgroup(g, [g.1, g.2*g.1*g.2*g.1*g.2^-1]));

2.

if quotient group is for equivalence relations, what do relations [g.1, g.2*g.1*g.2*g.1*g.2^-1] for? which kind of relations is for input to subgroup parameter which is like relations?

3. equalivance relations in wiki mentioned is to partition cells, how do they satisfy symmetric, reflexive and transitive after partition? how to test these partition?

how to implement a free group with symmetric properties?

i find that equivalence relations = relexive, symmetric and transitive , is only these three ?

if implement symmetric properties, does it mean that adding equivalence relations to group?

how to implement free group with this?

i guess something like

f := FreeGroup( "a", "b" );
g := f / [equivalence relations....];

is there a library storing all kinds of equivalence relations?
https://en.wikipedia.org/wiki/Equivalence_relation
For quotient groups, is there IsEquivalenceRelation and IsEquivalenceClass like gap system?
www.gap-system.org/Manuals/doc/ref/chap33.html
like
f := FreeGroup( "a", "b" );
g := f / [f.1^2, f.2^3, (f.1*f.2)^5];

when i paste words here, most words missing, is there being hacked?

I want to calculate

Lim _x-->1⁺ ([X²]-1)/([X]-1)

I let  x=1+c  and  _c-->0⁺  then we have [X²]=[c²+2c+1]=[2c]+1

Lim _x-->1⁺ ([X²]-1)/([X]-1) = Lim _c-->0⁺ [2c]/[c]

Maple shows the both limitations equal to zero

I want know how maple claculates it

I'd like to pay attention to Maple packages for symmetric functions, posets, root systems, and finite Coxeter groups by John Stembridge. That was estimated as well qualified in Mathoverflow.

Download Define_Question.mwDefine_Question.mw

If there is  an equation or are several equations, I need to obtain all the roots, how can I do???

fsolve ? rootfindings? or what?

If an examples of actual is given,  That will be perfect  !!!

Thanks 

Hi, there

How can we plot the volume of revolution of the region between two curves y=2x-x^2 and y=sqrt(2x-x^2) around the x-axis?

Any help will be appreciated. I used a command in maple 13 but the result was a sphere!

Regards

Yegan

Hi, I am new to Maple. I want to plot a graph in a separate window from command-line maple. I tried the following code and getting this error

> plotsetup(window);
> plot(x,x=-10..10);
Plotting error, no plot device driver for plotdevice=window
>

I tried maplet but I am not getting the plot

> plotsetup(maplet);
> plot(x,x=-10..10);
Initializing Java runtime environment.
>

What should I do to get the plot??

Hello,

I have a procedure wich is something like 

F:=proc(a,b,l) limit(f(a,b),b=l); end proc;

For my specific problem, the limit always exists and is a well defined function

After that, I would like to generate other functions, depending on F(a,b,l), e.g.:

G:=proc(a,b,N) add(F(a,b,l),l=1..N); end proc;

However, when I tried to do that, Maple inserts in G an unevaluated F, depending on the results of the limits. This makes G not work properly (unevaluated), since the limit is not computed before G. I tried to use some intermediate steps, like using unapply command, but it does not works.

If someone can help, I would appreciate.

Hi,

I have a problem with maple solving diffusion equation. I solved the equation as follows

Es := 0.117108e12;
Ef := 0.78125e11;
l := 0.150e-6;
s := 0.500000e-3;
f := 0.5898334197e-6;
o := 0.9e-5;
d := 0.10e-17;
cb := 0.1e7/(19.9);
c := l*f/(d*cb);
PDE := diff(u(x, t), t)-(diff(u(x, t), x, x)) = 0;
IBC1 := {u(x, 0) = 0, (D[1](u))(0, t) = 0, (D[1](u))(1, t) = c};
S1 := pdsolve(PDE, IBC1, numeric, time = t);
S1:-plot(t = 0.6e-2);

i am plotting cincentration along the thickness of the material. i want to know why the concentration is negative. It should not be negative because constant flux 'c' is present at x=1. and flux at x=0 is 0, and also the initial concentration is 0.

Thanks

 

How can I plot the volume of revolution of the region between the curves y=ln(x) and y=-ln(x)on the interval [1,e]

around the y-axis.please specify the command. I used the command: VolumeOfRevolution(ln(x),-ln(x), x=1..e, scaling=constrained,axis=vertical,output=plot). But this command only plots the revolution of the curves not the region between them.

Best Regards

Yegan 

Hi,

I would like to plot E2(t) , but It gives errors. How can I avoid the singularity and solve this problem?

restart: with(plots):
with(Student[NumericalAnalysis]):
g1:=(x,t)->(-sqrt(t)/(2*sqrt(Pi*r^3)))*(sin((r*(x-1)^(2)/(4*t))+(Pi/4))-sin((r*(x+1)^(2)/(4*t))+(Pi/4))):

g2:=(x,t)->int(g1(x,t),r=1..infinity);

g3:=(x,t) -> (diff(g2(x,t),t)):

g4:=(x,t) -> (diff(g2(x,t),x,x)):

g5:=(x,t) -> ((1/2)*(g3(x,t)^2+g4(x,t)^2)):

E2:=t->(int(g5(x,t),x=0..100)):

evalf(E2(0));
Error, (in g1) numeric exception: division by zero
evalf(E2(1));
Error, (in g3) invalid input: diff received 1, which is not valid for its 2nd argument
plot(E2(t),t=0..20);

Best regards,

Hej guys,

in some of my Maple worksheets I'm using Maples fit-function to obtain a rational function fit to some data, as I'm interested in the zeros of enumerator and denominator, I chose my fit function accordingly. Afterwards I need to extract the results (mainly the zeros) and do some more calculation steps with them. When evaluating rational functions of high degree, I noticed that my way of extracting the results (I'm using patmatch) becomes increasingly slow up to the point where it takes a couple of minutes to extract 10 numbers.
E.g. the following minimal example (download link at the bottom) takes more than 20 minutes on my machine (Maple 18.01 Build ID 935137; Red Hat Version 6.6 running on system with an i5-3570, 8 GB of RAM). Additionally, the calculation requires an unreasonable amount of RAM.
I can work around the problem to some degree by extracting the leading coefficient beforehand, resulting in a substantial speed up, still I think that there might be some error in the code or my usage of patmatch.

Is there another way to extract these numbers in a similarly simple fashion?

Cheers,

Sören

Download patmatch-breakdown.mw

I'm trying to plot the region bounded by the coordinate planes, the plane z=2-y and the cylinder x=4-y^2

This is what I have so far.  I want to know how to get rid of the portions of the planes and cylinder that are not enclosing the region.

restart;

with(plots);

xmin := 0;
xmax := 4;
ymin := 0;
ymax := 2;
zmin := 0;
zmax := 2;

a := plot3d([2-y], x = xmin .. xmax, y = ymin .. ymax, orientation = [40, 70], transparency = 0, color = green, filled = false, title = "");
%;

b := implicitplot3d([z = 0, y = 0, x = 0], x = xmin .. xmax, y = ymin .. ymax, z = zmin .. zmax, transparency = .5, axes = normal);
%;
c := implicitplot3d([x = -y^2+4], x = xmin .. xmax, y = ymin .. ymax, z = zmin .. zmax, transparency = .5, filled = true, axes = normal, color = blue, orientation = [45, 35]);

display(a, b, c);