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michaelmusty / BelyiDB

A Database of Belyi Maps
https://arxiv.org/abs/1805.07751
MIT License
2 stars 3 forks source link

Save Euclidean #20

Closed jvoight closed 2 years ago

jvoight commented 2 years ago

Matt Radosevich's code allows us to compute many many Euclidean Belyi maps.

How do they get saved? I only see the function GammasToBelyiDB; but I bet there's something somewhere in there, because we do display Euclidean Belyi maps in the LMFDB...

SamSchiavone commented 2 years ago

I think GammasToBelyiDB takes a sequence of triangle subgroups with all the Belyi map data computed and creates a corresponding BelyiDB object. You can then use BelyiDBWrite to write this BelyiDB object to file. (To read the file back in, there's BelyiDBRead.)

jvoight commented 2 years ago

Yep, that's right! But we can't make a Gamma currently as a triangle in the Euclidean case. 

>> TriangleGroup(2,4,4);
                ^
Runtime error: Must be hyperbolic (for now, sorry!)

I'm loathe to add that because we build on GrpPSL2 (making GrpPSL2Tri), and in the Euclidean case, you don't have a subgroup of PSL_2(RR). Maybe we can just rename?

SamSchiavone commented 2 years ago

Ah, I see. I think the intrinsic BelyiDBAdhoc on line 61 of query.m is how we dealt with spherical and Euclidean maps in the BelyiDB.