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CharacteristicClasses :: InputIsSmooth

InputIsSmooth

Description

The option InputIsSmooth is only used by the commands CSM, and Euler. If the input ideal is known to define a smooth subscheme setting this option to true will speed up computations (it is set to false by default).

i1 : R = ZZ/32749[x_0..x_4];
 
i2 : I=ideal(random(2,R),random(2,R),random(1,R));

o2 : Ideal of R
 
i3 : time CSM I
     -- used 1.22219 seconds

       3
o3 = 4h
       1

     ZZ[h ]
         1
o3 : ------
        5
       h
        1
 
i4 : time CSM(I,InputIsSmooth=>true)
     -- used 0.111845 seconds

       3
o4 = 4h
       1

     ZZ[h ]
         1
o4 : ------
        5
       h
        1

Note that one could, equivalently, use the command Chern instead in this case.

i5 : time Chern I
     -- used 0.147267 seconds

       3
o5 = 4h
       1

     ZZ[h ]
         1
o5 : ------
        5
       h
        1

Functions with optional argument named InputIsSmooth :

For the programmer

The object InputIsSmooth is a symbol.