s902.py

from research import *
s=begin(902,'Recover whole source-pair families from span and placement','Does the endpoint-coordinate basis reconstruct all supplied pairs exactly?',{},['C892 complete six','C831 Actual/Rounded weighted bridge'])
rows=json.loads((ROOT/'model/six_macro_heads.json').read_text())
inputs=[(r['id'],F(r['C']),F(r['R']),F(12)) for r in rows]+[('Actual_weighted',F(14004),F(4114),F(4,5)),('Rounded_weighted',F(14006),F(4106),F(4,5))]
out=[]
for name,c,r,k in inputs:
 d=c-r;w=k*c+(1-k)*r
 out.append({'id':name,'lambda':k,'D':d,'W':w,'recovered_C':w+(1-k)*d,'recovered_R':w-k*d,'source_C':c,'source_R':r})
a=artifact('model/endpoint_basis_recovery.json',json.dumps(clean(out),indent=2)+'\n')
finish(s,{'recovery':a,'weighted_rows':out[-2:]},'All six macro pairs and both weighted Creation pairs are recovered exactly. The Actual and Rounded weighted coordinates both equal12026, but their different spans9890 and9900 recover different original pairs. A shared coordinate alone does not merge them.','Compare whole-frame motion with source-fixed anchor changes across the new modules.',{'all_recovered':all(r['recovered_C']==r['source_C'] and r['recovered_R']==r['source_R'] for r in out),'weighted_equal':out[-1]['W']==out[-2]['W']==12026,'spans_differ':out[-1]['D']!=out[-2]['D']})