Top
Back: ellipticNF
Forward: realizationMatroids_lib
FastBack:
FastForward:
Up: polymake_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.13.1.17 ellipticNFDB

Procedure from library polymake.lib (see polymake_lib).

Usage:
ellipticNFDB(n[,#]); n int, # list

Assume:
n is an integer between 1 and 16

Purpose:
this is a database storing the 16 normal forms of planar polygons with precisely one interior point up to unimodular affine transformations
(see e.g. Bjorn Poonen, Fernando Rodriguez-Villegas: Lattice Polygons and the number 12. Amer. Math. Monthly 107 (2000), no. 3, 238--250.)

Return:
list, L such that
L[1] : list whose entries are the vertices of the nth normal form
L[2] : list whose entries are all the lattice points of the nth normal form
L[3] : only present if the optional parameter # is present, and then it is a polynomial in the variables (x,y) whose
Newton polygon is the nth normal form

Note:
the optional parameter is only allowed if the basering has the variables x and y

Example:
 
LIB "polymake.lib";
list nf=ellipticNFDB(5);
// the vertices of the 5th normal form are
nf[1];
// its lattice points are
nf[2];


Top Back: ellipticNF Forward: realizationMatroids_lib FastBack: FastForward: Up: polymake_lib Top: Singular Manual Contents: Table of Contents Index: Index About: About this document
            User manual for Singular version 4-0-3, 2016, generated by texi2html.