R help - Jul 2016 - unit root test

in thr name of God

Hi Dear

i try to test unit root of eff1 in my panel data = data1 but this is the
eroor what should i do ?


purtest(eff1~1,data=data1,index="indu",pmax=4,test="levinlin")


Error in purtest(eff1 ~ 1, data = data1, index = "indu", pmax = 4,
test "levinlin") :
  the individual dimension is undefined

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