# fan(Matrix,Matrix,List) -- Constructing a fan.

## Synopsis

• Function: fan
• Usage:
F = fan(M,N,L)
• Inputs:
• M, , Matrix containing the rays as columns.
• N, , Matrix containing generators of the lineality space as columns.
• L, a list, List containing lists with indices of the rays of the maximal cones.
• Outputs:
• F, an instance of the type Fan,

## Description

Basic constructor for fans that takes a matrix containing the rays of the fan and a list of lists with the indices of the rays in the maximal cones. Optionally one may provide a lineality space.

This constructor does not check well-definedness, see isWellDefined.

 i1 : M = matrix{{1,0},{0,1}} o1 = | 1 0 | | 0 1 | 2 2 o1 : Matrix ZZ <--- ZZ i2 : L = {{0,1}} o2 = {{0, 1}} o2 : List i3 : F = fan(M,L) o3 = F o3 : Fan i4 : N = matrix{{1},{1}} o4 = | 1 | | 1 | 2 1 o4 : Matrix ZZ <--- ZZ i5 : F1 = fan(M,N,L) o5 = F1 o5 : Fan