FCMakeIndex[str1, str2, head] generates an index with
the given head out of the string str1 and
str2. For example,
FCMakeIndex["Lor","1",LorentzIndex] yields
LorentzIndex[Lor1]. The second argument can also be an
integer. FCMakeIndex is useful for converting the output of
different diagram generators such as FeynArts or QGAF into the FeynCalc
notation. It uses memoization to improve the performance.
FCMakeIndex["Lor", "1"]\text{Lor1}
FCMakeIndex["Lor", "1"] // StandardForm
(*Lor1*)FCMakeIndex["Lor", {3, 1, 4}, LorentzIndex]\{\text{Lor3},\text{Lor1},\text{Lor4}\}
FCMakeIndex["Lor", {3, 1, 4}, LorentzIndex] // StandardForm
(*{LorentzIndex[Lor3], LorentzIndex[Lor1], LorentzIndex[Lor4]}*)FCMakeIndex["Sun", {"a", 1, -4}]\{\text{Suna},\text{Sun1},\text{SunMinus4}\}
FCMakeIndex["Sun", {"a", 1, -4}] // StandardForm
(*{Suna, Sun1, SunMinus4}*)