isomorphismTally -- group isomorphic modules or sheaves in a list

Usage:

isomorphismTally L
Inputs:
- L, a list, of modules or coherent sheaves
Optional inputs:
- Homogeneous (missing documentation) => ..., default value true,
- Strategy (missing documentation) => ..., default value null,
- Strict (missing documentation) => ..., default value false,
- Tries (missing documentation) => ..., default value null,
- Verbose (missing documentation) => ..., default value false,
Outputs:
- a list, of pairs consisting of a representative and its multiplicity

Description

The list is traversed up to isomorphism, returning one representative from each isomorphism class together with its count.

i1 : R = ZZ/101[x,y]/ideal(x^3, x^2*y^3, y^5);

i2 : F = res(coker vars R, LengthLimit => 5)

      1      2      4      8      16      32
o2 = R  <-- R  <-- R  <-- R  <-- R   <-- R
                                          
     0      1      2      3      4       5

o2 : Complex

i3 : netList isomorphismTally summands coker F.dd_5

     +----------------------------------------+
o3 = |(cokernel {7}  | x2   0 0  0 y4 0  |, 3)|
     |          {8}  | -48y x y3 0 0  0  |    |
     |          {10} | 0    0 0  y x  x2 |    |
     +----------------------------------------+
     |(cokernel {8} | y x |, 3)               |
     +----------------------------------------+
     |(cokernel {8} | x  0  y4 0   |, 2)      |
     |          {8} | -y x2 0  xy3 |          |
     +----------------------------------------+

Ways to use isomorphismTally:

isomorphismTally(List)

For the programmer

The object isomorphismTally is a method function with options.

The source of this document is in DirectSummands/docs.m2:680:0.

isomorphismTally -- group isomorphic modules or sheaves in a list

Description

See also

Ways to use isomorphismTally:

For the programmer