CheckSmooth

Description

The option CheckSmooth is only used by the commands CSM and only when computing the CSM class of a toric variety. It is set to true by default. When true it will check if the toric variety is smooth before proceeding, if it is this will speed up computation; however checking for smoothness does take some time.

i1 : needsPackage "NormalToricVarieties"

o1 = NormalToricVarieties

o1 : Package

i2 : U = toricProjectiveSpace 7

o2 = U

o2 : NormalToricVariety

i3 : time CSM U
 -- used 0.125624s (cpu); 0.125625s (thread); 0s (gc)

       7      6      5      4      3      2
o3 = 8x  + 28x  + 56x  + 70x  + 56x  + 28x  + 8x  + 1
       7      7      7      7      7      7     7

                                                ZZ[x ..x ]
                                                    0   7
o3 : -----------------------------------------------------------------------------------------------
     (x x x x x x x x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x )
       0 1 2 3 4 5 6 7     0    1     0    2     0    3     0    4     0    5     0    6     0    7

i4 : time CSM(U,CheckSmooth=>false)
 -- used 0.395045s (cpu); 0.316264s (thread); 0s (gc)

       7      6      5      4      3      2
o4 = 8x  + 28x  + 56x  + 70x  + 56x  + 28x  + 8x  + 1
       7      7      7      7      7      7     7

                                                ZZ[x ..x ]
                                                    0   7
o4 : -----------------------------------------------------------------------------------------------
     (x x x x x x x x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x , - x  + x )
       0 1 2 3 4 5 6 7     0    1     0    2     0    3     0    4     0    5     0    6     0    7

Functions with optional argument named CheckSmooth:

CSM(...,CheckSmooth=>...) -- see CSM -- The Chern-Schwartz-MacPherson class

For the programmer

The object CheckSmooth is a symbol.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/CharacteristicClasses.m2:2514:0.