cokerElement -- Gives an element in the cokernel of a matrix.

Synopsis

• Usage:

  cokerElement(v,A)

• Inputs:
  • v, a vector,
  • A, a matrix,
• Outputs:
  • a thing,

Description

i1 : A= matrix {{-1, -1, -1}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}}

o1 = | -1 -1 -1 |
     | 1  0  0  |
     | 0  1  0  |
     | 0  0  1  |

              4       3
o1 : Matrix ZZ  <-- ZZ

i2 : c1=cokerElement(vector {1,1,0,0},A)

o2 = | 2 |
     | 0 |
     | 0 |
     | 0 |

o2 : Vector

i3 : c2=cokerElement(vector {1,-1,0,0},A)

o3 = 0

o3 : Vector

i4 : c2==(0_(class c2))

o4 = true

i5 : iszero c2

o5 = true

See also

• inducedMap -- compute an induced map