I am working with the hourly electricity spot price data, due to the large dimensionality I convert the discrete data into functional data. The model I use the functional autoregressive model of order more than one, as per my knowledge there no R package available to deal with such model, so I apply an alternative method, using the functional principal components (FPC's) as dimensional reduction, utilizing the associated principal components for the forecasting through multivariate time series model. Then I convert these forecast scores into functional curves through Karhunen-Loeve decomposition into a functional form, in such a way I obtained a forecast of each day as a single curve. Know, to check the accuracy of the model I want to calculate percentage mean square error or mean absolute error. know my problem start from here, So I want to reverse back each curve into 24 discrete points, is there is any package in R which is helpful in dealing with such a problem.