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Chordal :: nodes

nodes -- list of nodes of a chordal network

Synopsis

Usage:

nodes N

nodes(N,i)
Inputs:
- N, an instance of the type ChordalNet,
- i, a ring element, a variable (optional)
Optional inputs:
- Reverse (missing documentation) => ..., default value false,
Outputs:
- a list, consisting of chordal network nodes

Description

This method returns the list of nodes of the chordal network. If the optional argument i is given, then only the nodes of rank i are returned.

i1 : R = QQ[x_0..x_3, MonomialOrder=>Lex];

i2 : I = ideal {x_0^3-x_0, x_0*x_2-x_2, x_1-x_2, x_2^2-x_2, x_2*x_3^2-x_3};

o2 : Ideal of R

i3 : N = chordalNet I;

i4 : chordalTria N;

i5 : N

                         2
o5 = ChordalNet{ x  => {x  - 1, x , x  - 1} }
                  0      0       0   0
                 x  => {x , x  - 1}
                  1      1   1
                 x  => {x , x  - 1}
                  2      2   2
                 x  => {x , x  - 1}
                  3      3   3

o5 : ChordalNet

i6 : nodes N

       2
o6 = {x  - 1, x , x  - 1, x , x  - 1, x , x  - 1, x , x  - 1}
       0       0   0       1   1       2   2       3   3

o6 : List

i7 : nodes(N,x_0)

       2
o7 = {x  - 1, x , x  - 1}
       0       0   0

o7 : List

See also

ChordalNet -- a chordal network
size(ChordalNet) -- size of a chordal network

Ways to use `nodes` :

"nodes(ChordalNet)"
"nodes(ChordalNet,RingElement)"

For the programmer

The object nodes is a method function with options.