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D.13.6.6 drawTropicalCurve
Procedure from library tropical.lib (see tropical_lib).
- Usage:
- drawTropicalCurve(f[,#]); f poly or list, # optional list
- Assume:
- f is list of linear polynomials of the form ax+by+c with
integers a, b and a rational number c representing a tropical
Laurent polynomial defining a tropical plane curve;
alternatively f can be a polynomial in Q(t)[x,y] defining
a tropical plane curve via the valuation map;
the basering must have a global monomial ordering, two
variables and up to one parameter!
- Return:
- NONE
- Note:
- - the procedure creates the files /tmp/tropicalcurveNUMBER.tex and
/tmp/tropicalcurveNUMBER.ps, where NUMBER is a random four
digit integer;
moreover it displays the tropical curve via xdg-open;
if you wish to remove all these files from /tmp,
call the procedure cleanTmp
- edges with multiplicity greater than one carry this multiplicity
- if # is empty, then the tropical curve is computed w.r.t. minimum,
if #[1] is the string 'max', then it is computed w.r.t. maximum
- if the last optional argument is 'onlytexfile' then only the
latex file is produced; this option should be used if xdg-utils
is not installed on your system
- note that lattice points in the Newton subdivision which are
black correspond to markings of the marked subdivision,
while lattice points in grey are not marked
Example:
| LIB "tropical.lib";
ring r=(0,t),(x,y),dp;
poly f=t*(x3+y3+1)+1/t*(x2+y2+x+y+x2y+xy2)+1/t2*xy;
// the command drawTropicalCurve(f) computes the graph of the tropical curve
// given by f and displays a post script image, provided you have xdg-open
drawTropicalCurve(f);
// we can instead apply the procedure to a tropical polynomial and use "maximum"
poly g=1/t3*(x7+y7+1)+t3*(x4+y4+x2+y2+x3y+xy3)+t21*x2y2;
list tropical_g=tropicalise(g);
tropical_g;
drawTropicalCurve(tropical_g,"max");
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