moebius.spad line 1 [edit on github]
MoebiusTransform(F) is the domain of fractional linear (Moebius) transformations over F.
eval(m, x) returns (a*x + b)/(c*x + d) where m = moebius(a, b, c, d) (see moebius).
eval(m, x) returns (a*x + b)/(c*x + d) where m = moebius(a, b, c, d) (see moebius).
moebius(a, b, c, d) returns matrix [[a, b], [c, d]].
recip() returns matrix [[0, 1], [1, 0]] representing the map x -> 1 / x.
recip(m) = recip() * m
scale(m, h) returns scale(h) * m (see shift).
scale(k) returns matrix [[k, 0], [0, 1]] representing the map x -> k * x.
shift(m, h) returns shift(h) * m (see shift).
shift(k) returns matrix [[1, k], [0, 1]] representing the map x -> x + k.