map(Module,RingElement) -- make a map

map(Module,RingElement) -- make a map

Synopsis:

Function: map -- make a map

Input:

an instance of class Module.

an instance of class RingElement.

Output:

an instance of class Matrix.

Optional arguments :

map(..., Degree)

map(..., DegreeMap => ...)

map(M,r) -- construct the map from M to itself which is provided by scalar multiplication by the ring element r.

i1 : R = ZZ/101[x]



o1 = R



o1 : PolynomialRing

i2 : map(R^2,x)



o2 = | x 0 |

     | 0 x |



             2       2

o2 : Matrix R  <--- R

See also:

map -- make a map

matrix -- make a matrix

Code:

     -- ../../../Macaulay2/m2/matrix.m2:546-552
     map(Module,RingElement) := Matrix => options -> (M,r) -> (
          R := ring M;
          try r = r + R#0
          else error "encountered scalar of unrelated ring";
          if r == 0 then map(M,M,0)
          else if r == 1 then map(M,1)
          else r * (map(M,1)))