next | previous | forward | backward | up | top | index | toc | Macaulay2 web site
map > map(Module,ZZ,Function)

map(Module,ZZ,Function) -- create a matrix from a free module by specifying a function that gives each entry

Synopsis

Description

This is the same as calling map(M,R^n,f), except that the degrees of the basis elements of the source module are chosen in an attempt to ensure that the resulting map is homogeneous of degree zero.
i1 : R = GF(9,Variable=>a)[x,y,z];
i2 : f = map(R^1, 3, (i,j) -> (a^j * x - y)^(j+1))

o2 = | x-y (a+1)x2+axy+y2 (-a-1)x3-y3 |

             1       3
o2 : Matrix R  <--- R
i3 : source f

      3
o3 = R

o3 : R-module, free, degrees {1..3}
i4 : isHomogeneous f

o4 = true

See also