I am new to R. I was trying to predict using holt method but getting this strange error. I am using forecast package V-7.1 with R (version 3.2.5) and Rstudio (Version 0.99.896). I reinstall all from R to Rstudio but did not work. Only h from 1 to 10 works. Any idea??
library(forecast)
library(stats)
library(base)
x=data$cost
k<-holt(x,damped=TRUE)
m=forecast(k,h=20)
Error in forecast.forecast(k, h = 20) :
Please select a longer horizon when the forecasts are first computed
Other testing cases:
m=forecast(k,h=2000)
Error in forecast.forecast(k, h = 2000) :
Please select a longer horizon when the forecasts are first computed
m=forecast(k,h=10)
m=forecast(k,h=11)
Error in forecast.forecast(k, h = 11) :
Please select a longer horizon when the forecasts are first computed
m=forecast(k,h=100)
Error in forecast.forecast(k, h = 100) :
Please select a longer horizon when the forecasts are first computed
You need to specify the h parameter in the call to holt(), not in the call to forecast().
holt() fits a model and computes the forecast. This is in contrast to "typical" R usage and other forecasting-related functions, like ets(), arima() etc. So you don't even need to call forecast() on the output of holt():
> print(holt(airmiles,h=15))
Point Forecast Lo 80 Hi 80 Lo 95 Hi 95
1961 32772.01 31455.62 34088.39 30758.77 34785.24
1962 34877.47 32594.37 37160.56 31385.77 38369.16
1963 36982.93 33767.27 40198.59 32065.00 41900.85
1964 39088.39 34912.84 43263.94 32702.44 45474.34
1965 41193.85 36015.50 46372.21 33274.24 49113.47
1966 43299.31 37070.39 49528.24 33773.00 52825.63
1967 45404.78 38076.33 52733.23 34196.88 56612.67
1968 47510.24 39033.57 55986.91 34546.29 60474.19
1969 49615.70 39942.98 59288.42 34822.56 64408.84
1970 51721.16 40805.71 62636.62 35027.41 68414.91
1971 53826.62 41622.95 66030.30 35162.71 72490.53
1972 55932.09 42395.93 69468.25 35230.32 76633.86
1973 58037.55 43125.82 72949.27 35232.03 80843.06
1974 60143.01 43813.77 76472.25 35169.60 85116.42
1975 62248.47 44460.85 80036.09 35044.65 89452.29