Strict transform of an ideal in Cox ring #4154
Conversation
TODO: tests, docstrings, documentation
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## master #4154 +/- ##
==========================================
- Coverage 84.69% 84.64% -0.05%
==========================================
Files 627 627
Lines 84300 84350 +50
==========================================
+ Hits 71399 71401 +2
- Misses 12901 12949 +48
|
| @assert grading_group(cox_ring(Y)) === class_group(Y) | ||
| G = class_group(Y) |
There was a problem hiding this comment.
First define G as the class_group(Y) and then use G in the assert, since you need G afterwards anyway and in the case of failure of the assert, you did not loose anything.
| n = number_of_generators(G) | ||
| new_var = cox_ring(Y)[index_of_new_ray(f)] | ||
| M = generator_degrees(cox_ring(Y)) | ||
| @assert M[index_of_new_ray(f)][n] < 0 "Assuming the blowup adds a new column vector to `Oscar.generator_degrees(cox_ring(codomain(f)))`, the entry of that vector corresponding to the new ray should be negative. If not, multiply by -1." |
There was a problem hiding this comment.
Your error messages in case of failing asserts seem pretty long to me. Please try to make them shorter and maybe add appropriate notes to the documentation instead.
| for i in 1:n_rays(Y) | ||
| i == index_of_new_ray(f) || @assert M[i][n] >= 0 "Assuming the blowup adds a new column vector to `Oscar.generator_degrees(cox_ring(codomain(f)))` for which the entry corresponding to the new ray is negative, the entries corresponding to all the other rays should be nonnegative. If not, add integer multiples of the other columns until it is." |
There was a problem hiding this comment.
Do you want to say
@assert findfirst(M[i][n] < 0 && i != index_of_new_ray(f) , 1:n_rays(Y)) === nothing
TODO: tests, docstrings, documentation