Macaulay2 » Documentation
Packages » SimplicialModules :: map(SimplicialModule,SimplicialModule,SimplicialModuleMap)
next | previous | forward | backward | up | index | toc

map(SimplicialModule,SimplicialModule,SimplicialModuleMap) -- make a new map of simplicial modules, induced from an existing one

Description

A map of simplicial modules $f : C' \rightarrow D'$ is a sequence of maps $f_i : C'_i \rightarrow D'_{d'+i}$. The new map $g : C \rightarrow D$ is the sequence of maps $g_i : C_i \rightarrow D_{d+i}$ induced by the matrix of $f_i$.

One use for this function is to get the new map of simplicial modules induced by forgetting the underlying complexes of the source and target, assuming that the source and target are obtained as Dold-Kan images.

i1 : R = ZZ/101[a,b,c];
i2 : C = simplicialModule(freeResolution coker vars R, Degeneracy => true)

      1      4      10      20
o2 = R  <-- R  <-- R   <-- R  <-- ...
                            
     0      1      2       3

o2 : SimplicialModule
i3 : f = map(forgetComplex C, forgetComplex C, id_C)

          1             1
o3 = 0 : R  <--------- R  : 0
               | 1 |

          4                       4
     1 : R  <------------------- R  : 1
               {0} | 1 0 0 0 |
               {1} | 0 1 0 0 |
               {1} | 0 0 1 0 |
               {1} | 0 0 0 1 |

          10                                   10
     2 : R   <------------------------------- R   : 2
                {0} | 1 0 0 0 0 0 0 0 0 0 |
                {1} | 0 1 0 0 0 0 0 0 0 0 |
                {1} | 0 0 1 0 0 0 0 0 0 0 |
                {1} | 0 0 0 1 0 0 0 0 0 0 |
                {1} | 0 0 0 0 1 0 0 0 0 0 |
                {1} | 0 0 0 0 0 1 0 0 0 0 |
                {1} | 0 0 0 0 0 0 1 0 0 0 |
                {2} | 0 0 0 0 0 0 0 1 0 0 |
                {2} | 0 0 0 0 0 0 0 0 1 0 |
                {2} | 0 0 0 0 0 0 0 0 0 1 |

          20                                                       20
     3 : R   <--------------------------------------------------- R   : 3
                {0} | 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 |
                {1} | 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 |
                {2} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 |
                {3} | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 |

o3 : SimplicialModuleMap
i4 : assert isWellDefined f
i5 : assert(degree f == 0)
i6 : assert isCommutative f
i7 : assert isSimplicialMorphism f
i8 : normalize f --notice how the normalization is not already pruned

          1             1
o8 = 0 : R  <--------- R  : 0
               | 1 |

     1 : image {0} | 0 0 0 | <----------------- image {0} | 0 0 0 | : 1
               {1} | 1 0 0 |    {1} | 1 0 0 |         {1} | 1 0 0 |
               {1} | 0 1 0 |    {1} | 0 1 0 |         {1} | 0 1 0 |
               {1} | 0 0 1 |    {1} | 0 0 1 |         {1} | 0 0 1 |

     2 : image {0} | 0 0 0 | <----------------- image {0} | 0 0 0 | : 2
               {1} | 0 0 0 |    {2} | 1 0 0 |         {1} | 0 0 0 |
               {1} | 0 0 0 |    {2} | 0 1 0 |         {1} | 0 0 0 |
               {1} | 0 0 0 |    {2} | 0 0 1 |         {1} | 0 0 0 |
               {1} | 0 0 0 |                          {1} | 0 0 0 |
               {1} | 0 0 0 |                          {1} | 0 0 0 |
               {1} | 0 0 0 |                          {1} | 0 0 0 |
               {2} | 1 0 0 |                          {2} | 1 0 0 |
               {2} | 0 1 0 |                          {2} | 0 1 0 |
               {2} | 0 0 1 |                          {2} | 0 0 1 |

     3 : image {0} | 0 | <------------- image {0} | 0 | : 3
               {1} | 0 |    {3} | 1 |         {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {1} | 0 |                      {1} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {2} | 0 |                      {2} | 0 |
               {3} | 1 |                      {3} | 1 |

o8 : ComplexMap
i9 : normalize id_C

          1             1
o9 = 0 : R  <--------- R  : 0
               | 1 |

          3                     3
     1 : R  <----------------- R  : 1
               {1} | 1 0 0 |
               {1} | 0 1 0 |
               {1} | 0 0 1 |

          3                     3
     2 : R  <----------------- R  : 2
               {2} | 1 0 0 |
               {2} | 0 1 0 |
               {2} | 0 0 1 |

          1                 1
     3 : R  <------------- R  : 3
               {3} | 1 |

o9 : ComplexMap
i10 : prune normalize f == normalize id_C

o10 = true

See also

Ways to use this method:


The source of this document is in /build/reproducible-path/macaulay2-1.26.05+ds/M2/Macaulay2/packages/SimplicialModules/SimplicialModuleDOC.m2:1550:0.