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MultiprojectiveVarieties :: degree(MultirationalMap)

degree(MultirationalMap) -- degree of a multi-rational map

Synopsis

Description

This is just a shortcut for (last multidegree Phi)/(degree image Phi).

i1 : ZZ/300007[x_0..x_3], f = rationalMap {x_2^2-x_1*x_3, x_1*x_2-x_0*x_3, x_1^2-x_0*x_2}, g = rationalMap {x_1^2-x_0*x_2, x_0*x_3, x_1*x_3, x_2*x_3, x_3^2};
i2 : Phi = last graph rationalMap {f,g};

o2 : MultirationalMap (rational map from threefold in PP^3 x PP^2 x PP^4 to PP^2 x PP^4)
i3 : time degree Phi
     -- used 1.28476 seconds

o3 = 1

See also