next | previous | forward | backward | up | top | index | toc | Macaulay2 website
MultiprojectiveVarieties :: multirationalMap(MultiprojectiveVariety,MultiprojectiveVariety)

multirationalMap(MultiprojectiveVariety,MultiprojectiveVariety) -- get the natural inclusion

Synopsis

Description

i1 : R = ZZ/101[a_0,a_1,b_0..b_2,Degrees=>{2:{1,0},3:{0,1}}], S = ZZ/101[c_0,c_1,d_0..d_2,Degrees=>{2:{1,0},3:{0,1}}]

o1 = (R, S)

o1 : Sequence
i2 : I = ideal (random({0,1},R),random({1,1},R)), J = sub(I,vars S)

o2 = (ideal (24b  - 36b  - 30b , - 29a b  - 10a b  + 19a b  - 29a b  + 19a b 
                0      1      2       0 0      1 0      0 1      1 1      0 2
     ------------------------------------------------------------------------
     - 8a b ), ideal (24d  - 36d  - 30d , - 29c d  - 10c d  + 19c d  - 29c d 
         1 2             0      1      2       0 0      1 0      0 1      1 1
     ------------------------------------------------------------------------
     + 19c d  - 8c d ))
          0 2     1 2

o2 : Sequence
i3 : X = projectiveVariety I, Y = projectiveVariety J

o3 = (X, Y)

o3 : Sequence
i4 : rationalMap(X,ambient X);

o4 : MultirationalMap (morphism from X to PP^1 x PP^2)
i5 : rationalMap(X,Y);

o5 : MultirationalMap (morphism from X to Y)
i6 : stopIfError = false;
i7 : rationalMap(ambient X,X)
stdio:7:1:(3): error: not able to define a natural map between the two varieties

See also