Greymodels is a Shiny application providing an interactive interface for statistical modelling and forecasting using grey-based models. It covers several state of-the-art univariate and multivariate grey models. A user friendly interface allows users to easily compare the performance of different models for prediction and among others, visualize graphical plots of predicted values within user chosen confidence intervals.
The latest release can be installed from CRAN:
install.packages("Greymodels")The latest development version can be installed from GitHub:
library(devtools)
install_github("havishaJ/Greymodels")
To run the app once the package is installed, use the following commands:
library(Greymodels)
run_app()The Greymodels package includes a Help tab that gives the use of the package and the different models implemented and an About Grey tab that explain the different categories of the grey models.
User data from a spreadsheet is easily loaded via the Browse button and the interface instantly provides information on fitted values, forecasts and interval estimates. Further, the user may visualize the plot of the raw, fitted and interval estimates. This further serves in the evaluation of the fitted approach used.
As a matter of example, using file1.xlsx and accessing the EPGM (1, 1) model under the Background Values tab, we follow
Univariate Models
The animated guide provides an overview of the use of data.
An example of how to use the extended grey model EGM (1, 1) model under the Extended Forms category is illustrated here. The EGM (1, 1) model requires an in-sample data file3.1.xlsx and out-sample data file3.2.xlsx. The in-sample data set is used to construct the model and the out-sample data set is used to evaluate how well it performs in predicting future values.