Items tagged with groebner

Feed

I try to sort a polynomial using the graded reverse lexicograpic order. According to the Documentation this is achieved via tdeg.
So here is what i tried:

 

with(Groebner):
sort( x+y+z, order = tdeg(x,y,z));

or

sort(x+y+z, [x,y,z], tdeg);

In both cases maple returns "x+y+z" instead of the expected "z+y+x". What am i doing wrong?

 

 

computer a Gröbner basis for <f_[1] = x^2*y - 2*y*z + 1, f_[2] = x*y^2-z^2+ 2*x,  f_[3] = y^2*z - x^2+ 5 > belong to Q[x,y,z], using ≺= <_grlex with x≺y≺z. compare your output to the Gröbner basis the Maple computers with a different order.

with(Groebner):
with(LinearAlgebra):
T := lexdeg([x1,x2,x3],[e1,e2,e3]);
GB := Basis([e1+.999987406876435, e2-.999919848203811],T):

Error, (in LinearAlgebra:-Basis) invalid input: LinearAlgebra:-Basis expects its 1st argument, V, to be of type {Vector, {set(Vector), list(Vector)}} but received [e1+HFloat(0.9999874068764352), e2-HFloat(0.9999198482038109)]


with(Groebner):
with(LinearAlgebra):
T := lexdeg([x1,x2,x3,x4,x5,x6,x7,x8],[e1,e2]);
GB := Basis([e1-x4*x2^3*x5/(x3*x1^4*x6), e2-x1*x8/(x3*x7)],T):

Error, (in LinearAlgebra:-Basis) invalid input: LinearAlgebra:-Basis expects its 1st argument, V, to be of type {Vector, {set(Vector), list(Vector)}} but received [e1-x4*x2^3*x5/(x3*x1^4*x6), e2-x1*x8/(x3*x7)]

with(Groebner):
with(LinearAlgebra):
T := lexdeg([x1,x2,x3],[e1,e2,e3]);
hello1 := proc(xx,yy)
return MatrixMatrixMultiply(xx,yy);
end proc:
hello2 := proc(xx,yy)
return xx+yy- MatrixMatrixMultiply(xx,yy);
end proc:
m1 := Matrix(3, 3, {(1, 1) = -.737663975994461+0.*I, (1, 2) = -.588973463383001+0.*I, (1, 3) = .330094104689369+0.*I, (2, 1) = -.588012653178741+0.*I, (2, 2) = .320157823261769+0.*I, (2, 3) = -.742792089286083+0.*I, (3, 1) = -.331802619371428+0.*I, (3, 2) = .742030476217061+0.*I, (3, 3) = .582492741708719+0.*I});
m2 := Matrix(3, 3, {(1, 1) = -.742269137704830+0.*I, (1, 2) = -.590598631673326+0.*I, (1, 3) = .316590877121441+0.*I, (2, 1) = -.593533033362923+0.*I, (2, 2) = .360143915024171+0.*I, (2, 3) = -.719732518911068+0.*I, (3, 1) = -.311054762892221+0.*I, (3, 2) = .722142379823161+0.*I, (3, 3) = .617863510611693+0.*I});
m3 := Matrix(3, 3, {(1, 1) = -.751491355856820+0.*I, (1, 2) = -.574908634018322+0.*I, (1, 3) = .323636840615627+0.*I, (2, 1) = -.575794245520782+0.*I, (2, 2) = .332066412772496+0.*I, (2, 3) = -.747123071744916+0.*I, (3, 1) = -.322058579916187+0.*I, (3, 2) = .747804760642505+0.*I, (3, 3) = .580574121936877+0.*I});
AA := hello1(m1, m2);
BB := hello2(m1, m2);
GB := Basis([e1- AA,e2- BB],T):
NormalForm(m3, GB, T);

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 ]

http://www.maplesoft.com/support/help/view.aspx?sid=2953

g1 := Vector([1, 1]);g2 := Vector([x+y, 0]);g3 := Vector([y^2+1, 0]);g4 := Vector([0, y^3+y]);g5 := Vector([0, x-y]);

i pass and tdeg(x, y, h251, h252, h253, h254, h255) to Basis

failed in Maple 15

http://www.mapleprimes.com/questions/144384-Polynomials-Not-In-The-Correct-Indeterminates

above link's comment said eliminate will NOT generate a polynomial in all cases

make me think that eliminate in above link can not return correct one.

what is the correct way to convert groebner basis of kernel into kernel?

below code is calculate basis of kernel and kernel

i guess basis of image is 

remove(has, Ga, [r,u,v,w]); if this correct, i eliminate this, i can get the image
however it include variable 'a'
is it correct? if not, how to calculate? 
my final goal is to make unexact sequence into exact sequence
restart;
with(Groebner):
g1 := x^2-w*y;
g2 := x*y-w*z;
g3 := y^2-x*z;
S13 := -y^3*w+x^3*z;
eq1:= S13 = h131*g1 + h132*g2 + h133*g3;

hsol := solve(identity(eq1, x), [h131, h132, h133]);
match(eq1,{x,y,z,w},'s');
s;
 
h131 should be x*z
h312 should be 0
h133 should be -y*w
 

3*rho1 - 2*rho2 + rho3 - rho4 = -1

4*rho1 +   rho2 - rho3        = 5

original without cost function:

with(Groebner):
K := {y1-(x1^3)*(x2^4),y2-(x2^(1+2))*(w^2),y3-(x1^(1+1))*(w^1),y4-(x2^1)*w,(y1^1000)*(y2^1)*(y3^1)*(y4^100)- x1*x2*w + 1};
G := Basis(K, plex(x1, x2, w, y1, y2, y3, y4));
Reduce((x2^(5+1))*(w^1), G, plex(x1, x2, w, y1, y2, y3, y4));

after have cost function 1000*rho1 + rho2...

Hello. I am trying to do a project. Howerver the following code is causing Windows 7(x64) to error.

First, I get a message from mserver.exe saying: mserver has stopped working.

I click "Close the program" and I get "Kernel connection has been lost."

This is happening when I calculate the Groebner Basis by the following code. It is all right when I calculate the Groebner Basis when the problem to be solved is simpler. The memory of my computer is...

Hi,

I'm trying to solve system of linear and nonlinear equations with inequalities and it looks like this:

 

    SX := solve(
                   [
                       seq(diff(EX,WX[k+1])=0, k = 0..m), # these are linear
 ...

I have a rather large multivatiate polynomial "Dtest"  I need to divie it by a cubic poly "DGm" using rem and quo. Both are determinants multiplied out,  both given below. Have spent the past 2 nights trying to sort, collect, expand, equate coefficients plex groebner etc. Am trying to collect up all the powers of c3 but cant anything to work. even expand doesn't fully expand "Dtest". If I set c1 and c2 to 1 things are...

I'm trying to write a program that solves sudoku's using a Groebner basis. I introduced 81 variables x1 to x81, this is a linearisation of the sudoku board.

The space of valid sudokus is defined by:


for i=1,…,81 : Fi=(xi−1)(xi−2)⋯(xi−9) This represents the fact that all squares have integer values between 1 and 9.

for all xi and xj which...

1 2 3 4 Page 3 of 4