maps=[ps.LinearMorphism(np.matrix([1, 1]))]), ps.SheafMorphismCell(destinations=[1], maps=[ps.LinearMorphism(np.matrix(1))]), ps.SheafMorphismCell(destinations=[2], maps=[ps.LinearMorphism(np.matrix(1))]) ]) print 'degree 0 induced map Collapsed->Line: ' + str( ps.inducedMap(ColLoopSheaf, LineSheaf, MorColLine, 0)) print 'degree 1 induced map Collapsed->Line: ' + str( ps.inducedMap(ColLoopSheaf, LineSheaf, MorColLine, 1)) print 'degree 2 induced map Collapsed->Line: ' + str( ps.inducedMap(ColLoopSheaf, LineSheaf, MorColLine, 2)) PerSheaf0 = ps.PersistenceSheaf([ColLoopSheaf, LineSheaf, LoopSheaf], [(0, 1, MorColLine), (0, 2, MorColLoop)], 0) print '0-Persistent degree 0 Sheaf Betti number ' + str( PerSheaf0.cobetti(0)) print '0-Persistent degree 1 Sheaf Betti number ' + str( PerSheaf0.cobetti(1)) PerSheaf1 = ps.PersistenceSheaf([ColLoopSheaf, LineSheaf, LoopSheaf], [(0, 1, MorColLine), (0, 2, MorColLoop)], 1) print '1-Persistent degree 0 Sheaf Betti number ' + str( PerSheaf1.cobetti(0)) print '1-Persistent degree 1 Sheaf Betti number ' + str( PerSheaf1.cobetti(1))
# Distribution of unaltered copies permitted for noncommercial use only # All other uses require express permission of the author # This software comes with no warrantees express or implied import numpy as np import pysheaf as ps if __name__ == '__main__': targ1=ps.DirectedGraph([(None,1),(1,2),(2,None),(None,3),(3,4),(4,None)]) fs1=ps.FlowSheaf(targ1) targ2=ps.DirectedGraph([(None,1),(None,1),(1,2),(2,None),(2,None)]) targ3=ps.DirectedGraph([(None,1),(None,1),(1,2),(2,None)]) map1=[(0,0),(1,2),(2,3),(3,1),(4,2),(5,4),(6,5),(7,6),(8,5),(9,6)] map2=[(0,0),(1,1),(2,2),(3,3),(4,3),(5,4)] print 'Ready to compute!' pf1,pf1m=fs1.pushForward(targ2,map1) print 'pushforward FS 1 induced map ' + str(ps.inducedMap(pf1,fs1,pf1m,0)) fs2,fsm2=pf1.flowCollapse() print 'collapse 1 induced map ' + str(ps.inducedMap(pf1,fs2,fsm2,0)) pf2,pf2m=fs2.pushForward(targ3,map2) print 'pushforward FS 2 induced map ' + str(ps.inducedMap(pf2,fs2,pf2m,0)) fs3,fsm3=pf2.flowCollapse() print 'collapse 2 induced map ' + str(ps.inducedMap(pf2,fs3,fsm3,0)) persh=ps.PersistenceSheaf([fs1,pf1,fs2,pf2,fs3],[(1,0,pf1m),(1,2,fsm2),(3,2,pf2m),(3,4,fsm3)],0) print 'Persistence Sheaf Betti 0=' + str(persh.cobetti(0))