GreyModel (version 0.1.0)

GM_test: Grey Model Test for Data Suitability

Description

The GM_test function test the suitability of data for Grey modelling.

Usage

GM_test(data)

Arguments

data

Input univariate time series (ts) data.

Value

Test_Result

If the data is suitable for grey modelling, <U+201C>data is suitable for Grey modelling<U+201D> will be printed; otherwise, <U+201C>data is not suitable for Grey modelling<U+201D> will be printed.

Details

On the considered time series data, this function computes the ratio sequence. The data is suitable for grey modelling if the sequence value falls between 0.1345 and 7.389 (Hsu and Wang, 2007).

References

Hsu, L. and Wang, C. (2007). Forecasting the output of integrated circuit industry using a grey model improved by the Bayesian analysis. Technological Forecasting and Social Change, 74, 843--853.

See Also

GM, fcast_grey

Examples

# NOT RUN {
xt <- c(640,724,813,1145,1509,2122,1883,2413,2834,4235,7144,5269)
GM_test(data=xt)
# }