curveClassRepresentativeM0nbar(ZZ,HashTable) -- creates an object of type CurveClassRepresentativeM0nbar

Synopsis

Function: curveClassRepresentativeM0nbar
Usage:

curveClassRepresentativeM0nbar(H)
Inputs:
- n, an integer,
- H, a hash table,
Outputs:
- an instance of the type CurveClassRepresentativeM0nbar,

Description

This function creates an object of type CurveClassRepresentativeM0nbar from a hash table. Here is a basic example:

i1 : H1=new HashTable from { {{{1,2},{3},{4},{5}},1}, {{{1,3},{2},{4},{5}},1} };

i2 : curveClassRepresentativeM0nbar(5,H1)

o2 = CurveClassRepresentativeM0nbar{"CurveExpression" => HashTable{{{1, 2}, {3}, {4}, {5}} => 1}}
                                                                   {{1, 3}, {2}, {4}, {5}} => 1
                                    "NumberOfMarkedPoints" => 5

o2 : CurveClassRepresentativeM0nbar

Warning: when you enter a hash table in Macaulay2, if you use a key more than once, the first instance is discarded. Here is an example where the behavior may differ from what you want:

i3 : H=new HashTable from { {{{1,2},{3},{4},{5}},1}, {{{1,3},{2},{4},{5}},1}, {{{1,2},{3},{4},{5}},2}}

o3 = HashTable{{{1, 2}, {3}, {4}, {5}} => 2}
               {{1, 3}, {2}, {4}, {5}} => 1

o3 : HashTable

The user probably wanted $F_{\{1,2\},\{3\},\{4\},\{5\}} + 2F_{\{1,2\},\{3\},\{4\},\{5\}}$ to give $3F_{\{1,2\},\{3\},\{4\},\{5\}}$ instead. So if your expression has two terms that are written exactly alike, you could either combine them before you create the input hash table, or input a list instead.

i4 : L= { {{{1,2},{3},{4},{5}},1}, {{{1,3},{2},{4},{5}},1}, {{{1,2},{3},{4},{5}},2}}

o4 = {{{{1, 2}, {3}, {4}, {5}}, 1}, {{{1, 3}, {2}, {4}, {5}}, 1}, {{{1, 2},
     ------------------------------------------------------------------------
     {3}, {4}, {5}}, 2}}

o4 : List

i5 : curveClassRepresentativeM0nbar(5,L)

o5 = CurveClassRepresentativeM0nbar{"CurveExpression" => HashTable{{{1, 2}, {3}, {4}, {5}} => 3}}
                                                                   {{1, 3}, {2}, {4}, {5}} => 1
                                    "NumberOfMarkedPoints" => 5

o5 : CurveClassRepresentativeM0nbar

For this reason, most users will probably prefer to enter curves via lists, rather than hash tables.

The function curveClassRepresentative does the same minimal testing if you enter a hash table that it does if you enter a list. See the documentation for curveClassRepresentativeM0nbar(ZZ,List).

Ways to use this method: