I have been struggling (reading Ore/Weyl Algebra documentation) to understand how to input a PDE system with polynomial coeff. in Weyl algebra notation so I can compute a Groebner basis for it. I would be very grateful if someone could  show, using the simple example below, which differential operators in Ore_algebra[diff_algebra] should one declare to express the system in Weyl algebra notation. The systems I'm working are more complicated but all have many dependent variables, f and g functions in this example:

pdesys:= [ x*diff( f(x,y,z),x)- z*diff( g(x,y,z),y) = 0, (x^2-y)*diff( f(x,y,z),z)- y*diff( g(x,y,z),z) = 0 ]

I am struggling to get a single output value for my piece wise function. I am trying to plot this piecewise function. All the B-values and L value are previously defined.

My end goal is to plot the function.

Unfortunately, I cannot get the piecewise function to output a single value. I have tried s(2) which gives me the entire piecewise function with the correct numbers plugged in.

Here is the file in its full form.

damshw9.mw

I am trying to expand  a rational function that is in the form:

P(z) = (1 + z⁻¹)² (1 + z)²· (r1z + r0 + r1z⁻¹)

to the form:

P(z) = r1z³ + (4r1 + r0)z² + (7r1 + 4r0)z + (8r1 + 6r0)

+(7r1 + 4r0)z⁻¹ + (4r1 + r0)z⁻² + r1z⁻³

Can someone show me how to do this please?

I am getting an error dialog when I try to Browse an array I created programmatically.  The title of the dialog is RTable Browse Error with and error that says Empty RTable Structure. 

Now the data is 0..20 x 0..1 Array Datatype :anything Storage: rectangular

Order: Fortran_Order. 

If I do a showall, I can see the data, I just cannot browse it.  Any help would be appreciated.

Code is:

for i from 1 to N do
 t:=h*i:
 X[i,0]:=x1+h*(-x1)*x2+x1:
 X[i,1]:=x2+h*x1*x2-x2:
 x1:=X[i,0]:
 x2:=X[i,1]:
 print('Iteration',i,'AtTime',t,x1,x2)
end do;
print(X);

Thanks

Melvin

I am to program a computation on maple.
But I get the message :

Error, unable to match delimiters

followed by the full sequence of command.

How can I do to fix this problem?

Hi everyone, I'm trying to find the value of f but I always have this error message : Error, (in BesselJ) too many levels of recursion.

Here is the function:

f(t)=BesselJ(0, t)+int(BesselJ(0, x)*f(t-x), x = 0 .. t)

Is there any way that I can isolate my f without having to rewrite the equation using laplace transform properties?

Thanks,

Frank

I want my graphic to be like this (file: Hansevi's Graphic.mw ):

instead of this (file: My graphic.mw):

Does anyone know why both graphics are different?

*The graphics were supposed to be similar -_-

I am trying to solve a nonlinear second order ODE with a parameter to be determined. I can set up most of the problem but I am having trouble trying to tell the computer the following boundary condition,

diff(f(x),x) = -K on f(x)=0.

(K will be inputted and is not to be solved for) As i said before, the other boundary conditions are fine and the numerical solution works if i use different boundary conditions. 

For other boundary conditions (for example df/dx = 0 at x=0) I write in the form 

D(f)(0)=0

I hope this makes sense and someone has a solution. Thanks in advance.

Matt

c1 := u1*u2-u1*u3;

c2 := -u1*u2+u2*u3-(1/2)*((u2-u3)*(u1*u2-u1*u3)+(u1)*(-u1*u2+u2*u3)-(u1)*(u1*u3-u2*u3))/(u1);

c3 := u1*u3-u2*u3+(1/2)*((u2-u3)*(u1*u2-u1*u3)+(u1)*(-u1*u2+u2*u3)-(u1)*(u1*u3-u2*u3))/(u1);

c4 := u1;

d1 := subs(u3=u3(t),subs(u2=u2(t),subs(u1=u1(t),c1)));

d2 := subs(u3=u3(t),subs(u2=u2(t),subs(u1=u1(t),c2)));

d3 := subs(u3=u3(t),subs(u2=u2(t),subs(u1=u1(t),c3)));

d4 := subs(u3=u3(t),subs(u2=u2(t),subs(u1=u1(t),c4)));

sys := {Diff(u1(t), t) = d1,

Diff(u2(t), t) = d2,

Diff(u3(t), t) = d3,

y = d4};

sys := {Diff(u1(t), t) = d1,

Diff(u2(t), t) = d2,

Diff(u3(t), t) = d3};

with(DEtools):

DEplot(sys, [u1(t), u2(t), u3(t)], t = 0 .. 15,number = 3, [[u1(0) = 0, u2(0) = 0, u3(0) = 0]]);

Error, (in DEtools/DEplot/WhichPlot) More than two dependent variables - please indicate the desired scene.

I'm using Maple 17 to seperate a large set of equations. I used selectremove command but the problem is it cannot return to zero when I select a varuable whish is not appear in this equation (it's showed on the figure below)!
Thanks!

Hi All,

I tried to convert the following hypergeometric function into BesselJ function. But I failed to do so. Could any one let me know the  reference or procedure to convert the Hypergeom function into bessel function.

Following is the integral I am intended to do.

Result:

I need to convert the result into equivalent bessel function.

If at all there is a way to co-relate the generalized corelation between bessel function <-> hypergeom function.

Direct me to any books you come across.

Thanks

Good afternoon sir.

I request your kind support to the above cited question.

With thanks & Regards

M.Anand

Assistant Professor in Mathematics

SR International Institute of Technology,

Hyderabad, Andhra Pradesh, INDIA.

I need help writing a function which takes a number of integers (which are greater than or equal to 2) and returns a list where the nth entry in the list is given by the number of arguments which can be expressed in the form of x^n where x is an integer. The function must also disregard all of the terms after the final integer greater than 0 is produced ie does not show 0, 0, 0, 0, at the end of the list.

Eg if f was the function f(27) = [1,0,1]

f(2,3,4,9,81,1024) = [6,4,0,1,1,0,0,0,0,1]

I'm in desperate need for help!! For an assignment, we were asked to "write out our first and last names" in maple, using correct upper and lower case letters. I am clueless on how to approach the assignment. Is there anyone that could help me?

Hello,

I am using Maple Physics for symbolic tensor computations. However, I fail to simplify quite a simple expression.

Consider the following code:

    with(Physics):with(Library):

    Setup(spacetimeindices = lowercaselatin):

    Define(F[a]);

    read "example2.txt"; 

    Simplify(%);

Here is a file with expression: example2.txt.

The expression in the example2.txt is equal to zero. The following steps allow to obtain this result: expand, contract Kronecker deltas and metric tensors and collect similar terms. This also can be verified using another software (Cadabra, Mathematica xAct, etc.). As one can see, the result of Maple Simplify(%) contains terms like -462661905780*F[k]*F[~k] - 5856479820*F[m]*F[~m] which can be futher simplified, but Maple does not do this (even when I invoke Simplify(%) several times).

What is the right sequence of manipulations needed to obtain zero?

I use the latest Physics package (39.2, updated on November 30).

Thanks,

Dmitry.