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GlicciPointsInP3 :: hasFactor

hasFactor -- check for a factor of desired degree

Synopsis

Description

The function checks whether the polynomial f has a factor of degree n defined over the field of definition. In case where the argument is an ideal I of points, we check for a subscheme of degree n.
i1 : R=ZZ/10009[x,y]

o1 = R

o1 : PolynomialRing
i2 : setRandomSeed("degree 3 factor");
i3 : f=random(8,R)

         8        7         6 2       5 3        4 4       3 5       2 6  
o3 = 617x  + 3641x y - 3982x y  - 640x y  + 2859x y  - 187x y  - 867x y  -
     ------------------------------------------------------------------------
            7       8
     2692x*y  + 158y

o3 : R
i4 : apply(decompose ideal f,c->degree c)

o4 = {1, 2, 5}

o4 : List
i5 : hasFactor(f,3)

o5 = true
i6 : hasFactor(f,4)

o6 = false

Ways to use hasFactor :