I want to use holt() function on R, and apply it on a time series ts. But I get this error and don't understand why:
holt(timeseries)
Error in etsTargetFunctionInit(par = par, y = y, nstate = nstate, errortype = errortype, : Not compatible with requested type: [type=character; target=double]. In addition: Warning message: In is.constant(y) : NAs introduced by coercion
I get the same error when I try other forecasting functions like thetaf and ses.