1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
# Function to create alllabels file mapping Cremona labels to LMFDB labels
#
# Input: curves file, e.g. curves.230000-239999
#
# Output: alllabels file, e.g. alllabels.230000-239999
#
# Format: conductor iso number conductor lmfdb_iso lmfdb_number
#
# NB we do this by computing the isogeny class and (re)sorting it in
# each case. This is ONLY intended for ranges where the classes
# themselves are in the correct order.
#
from sage.all import EllipticCurve
def make_alllabels(infilename, mode='w', pref='t', verbose=False):
infile = open(infilename)
pre, suf = infilename.split(".")
alllabelsfile = open(pref+"alllabels."+suf, mode=mode)
count=0
for L in open(infilename).readlines():
count +=1
if count%1000==0:
print(L)
N, cl, num, ainvs, r, tor, d = L.split()
E = EllipticCurve(eval(ainvs))
curves = E.isogeny_class(order="sage").curves
reordered_curves = sorted(curves, key = lambda E: E.a_invariants())
lab1 = range(1,len(curves)+1)
lab2 = [1+reordered_curves.index(EE) for EE in curves]
for j in range(len(curves)):
line = ' '.join([N,cl,str(lab1[j]),N,cl,str(lab2[j])])
alllabelsfile.write(line+'\n')
if verbose:
print("alllabelsfile: "+line)
infile.close()
alllabelsfile.close()
|
