healthyverse_tsa

Time Series Analysis and Nested Modeling of the Healthyverse Packages

Steven P. Sanderson II, MPH - Date: 09 July, 2025

This analysis follows a Nested Modeltime Workflow.

Get Data

glimpse(downloads_tbl)
## Rows: 144,864
## Columns: 11
## $ date      <date> 2020-11-23, 2020-11-23, 2020-11-23, 2020-11-23, 2020-11-23,…
## $ time      <Period> 15H 36M 55S, 11H 26M 39S, 23H 34M 44S, 18H 39M 32S, 9H 0M…
## $ date_time <dttm> 2020-11-23 15:36:55, 2020-11-23 11:26:39, 2020-11-23 23:34:…
## $ size      <int> 4858294, 4858294, 4858301, 4858295, 361, 4863722, 4864794, 4…
## $ r_version <chr> NA, "4.0.3", "3.5.3", "3.5.2", NA, NA, NA, NA, NA, NA, NA, N…
## $ r_arch    <chr> NA, "x86_64", "x86_64", "x86_64", NA, NA, NA, NA, NA, NA, NA…
## $ r_os      <chr> NA, "mingw32", "mingw32", "linux-gnu", NA, NA, NA, NA, NA, N…
## $ package   <chr> "healthyR.data", "healthyR.data", "healthyR.data", "healthyR…
## $ version   <chr> "1.0.0", "1.0.0", "1.0.0", "1.0.0", "1.0.0", "1.0.0", "1.0.0…
## $ country   <chr> "US", "US", "US", "GB", "US", "US", "DE", "HK", "JP", "US", …
## $ ip_id     <int> 2069, 2804, 78827, 27595, 90474, 90474, 42435, 74, 7655, 638…

The last day in the data set is 2025-07-07 21:30:55, the file was birthed on: 2024-08-07 07:35:44.428716, and at report knit time is -8025.92 hours old. Happy analyzing!

Now that we have our data lets take a look at it using the skimr package.

skim(downloads_tbl)
   
Name downloads_tbl
Number of rows 144864
Number of columns 11
_______________________  
Column type frequency:  
character 6
Date 1
numeric 2
POSIXct 1
Timespan 1
________________________  
Group variables None

Data summary

Variable type: character

skim_variable n_missing complete_rate min max empty n_unique whitespace
r_version 104720 0.28 5 5 0 48 0
r_arch 104720 0.28 3 7 0 5 0
r_os 104720 0.28 7 15 0 23 0
package 0 1.00 7 13 0 8 0
version 0 1.00 5 17 0 60 0
country 12235 0.92 2 2 0 163 0

Variable type: Date

skim_variable n_missing complete_rate min max median n_unique
date 0 1 2020-11-23 2025-07-07 2023-07-19 1688

Variable type: numeric

skim_variable n_missing complete_rate mean sd p0 p25 p50 p75 p100 hist
size 0 1 1131584.65 1513383.09 355 14701 293058 2367682 5677952 ▇▁▂▁▁
ip_id 0 1 10454.41 18585.19 1 285 3037 11827 209747 ▇▁▁▁▁

Variable type: POSIXct

skim_variable n_missing complete_rate min max median n_unique
date_time 0 1 2020-11-23 09:00:41 2025-07-07 21:30:55 2023-07-19 18:19:49 88973

Variable type: Timespan

skim_variable n_missing complete_rate min max median n_unique
time 0 1 0 59 16 60

We can see that the following columns are missing a lot of data and for us are most likely not useful anyways, so we will drop them c(r_version, r_arch, r_os)

Plots

Now lets take a look at a time-series plot of the total daily downloads by package. We will use a log scale and place a vertical line at each version release for each package.

Now lets take a look at some time series decomposition graphs.

Feature Engineering

Now that we have our basic data and a shot of what it looks like, let’s add some features to our data which can be very helpful in modeling. Lets start by making a tibble that is aggregated by the day and package, as we are going to be interested in forecasting the next 4 weeks or 28 days for each package. First lets get our base data.

## 
## Call:
## stats::lm(formula = .formula, data = df)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -148.78  -36.03  -11.32   26.71  816.07 
## 
## Coefficients:
##                                                      Estimate Std. Error
## (Intercept)                                        -1.718e+02  6.584e+01
## date                                                1.060e-02  3.486e-03
## lag(value, 1)                                       1.044e-01  2.411e-02
## lag(value, 7)                                       9.437e-02  2.495e-02
## lag(value, 14)                                      8.667e-02  2.494e-02
## lag(value, 21)                                      6.554e-02  2.511e-02
## lag(value, 28)                                      7.064e-02  2.499e-02
## lag(value, 35)                                      6.782e-02  2.508e-02
## lag(value, 42)                                      5.648e-02  2.519e-02
## lag(value, 49)                                      6.537e-02  2.506e-02
## month(date, label = TRUE).L                        -9.740e+00  5.109e+00
## month(date, label = TRUE).Q                         3.369e+00  5.057e+00
## month(date, label = TRUE).C                        -1.331e+01  5.125e+00
## month(date, label = TRUE)^4                        -6.816e+00  5.113e+00
## month(date, label = TRUE)^5                        -1.131e+01  5.105e+00
## month(date, label = TRUE)^6                        -4.068e+00  5.162e+00
## month(date, label = TRUE)^7                        -7.101e+00  5.065e+00
## month(date, label = TRUE)^8                        -3.011e+00  5.054e+00
## month(date, label = TRUE)^9                         5.271e+00  5.044e+00
## month(date, label = TRUE)^10                        2.629e+00  5.050e+00
## month(date, label = TRUE)^11                       -3.686e+00  5.023e+00
## fourier_vec(date, type = "sin", K = 1, period = 7) -1.180e+01  2.307e+00
## fourier_vec(date, type = "cos", K = 1, period = 7)  8.115e+00  2.427e+00
##                                                    t value Pr(>|t|)    
## (Intercept)                                         -2.610 0.009142 ** 
## date                                                 3.042 0.002389 ** 
## lag(value, 1)                                        4.331 1.58e-05 ***
## lag(value, 7)                                        3.782 0.000161 ***
## lag(value, 14)                                       3.475 0.000525 ***
## lag(value, 21)                                       2.609 0.009152 ** 
## lag(value, 28)                                       2.827 0.004753 ** 
## lag(value, 35)                                       2.704 0.006926 ** 
## lag(value, 42)                                       2.242 0.025092 *  
## lag(value, 49)                                       2.609 0.009178 ** 
## month(date, label = TRUE).L                         -1.907 0.056757 .  
## month(date, label = TRUE).Q                          0.666 0.505392    
## month(date, label = TRUE).C                         -2.596 0.009504 ** 
## month(date, label = TRUE)^4                         -1.333 0.182691    
## month(date, label = TRUE)^5                         -2.216 0.026844 *  
## month(date, label = TRUE)^6                         -0.788 0.430823    
## month(date, label = TRUE)^7                         -1.402 0.161088    
## month(date, label = TRUE)^8                         -0.596 0.551423    
## month(date, label = TRUE)^9                          1.045 0.296219    
## month(date, label = TRUE)^10                         0.521 0.602696    
## month(date, label = TRUE)^11                        -0.734 0.463117    
## fourier_vec(date, type = "sin", K = 1, period = 7)  -5.117 3.47e-07 ***
## fourier_vec(date, type = "cos", K = 1, period = 7)   3.344 0.000845 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 58.73 on 1616 degrees of freedom
##   (49 observations deleted due to missingness)
## Multiple R-squared:  0.2379, Adjusted R-squared:  0.2275 
## F-statistic: 22.93 on 22 and 1616 DF,  p-value: < 2.2e-16

NNS Forecasting

This is something I have been wanting to try for a while. The NNS package is a great package for forecasting time series data.

NNS GitHub

library(NNS)

data_list <- base_data |>
    select(package, value) |>
    group_split(package)

data_list |>
    imap(
        \(x, idx) {
            obj <- x
            x <- obj |> pull(value) |> tail(7*52)
            train_set_size <- length(x) - 56
            pkg <- obj |> pluck(1) |> unique()
            sf <- NNS.seas(x, modulo = 7, plot = FALSE)$periods
            
            cat(paste0("Package: ", pkg, "\n"))
            NNS.ARMA.optim(
                variable = x,
                h = 28,
                training.set = train_set_size,
                #seasonal.factor = seq(12, 60, 7),
                seasonal.factor = sf,
                pred.int = 0.95,
                plot = TRUE
            )
            title(
                sub = paste0("\n",
                             "Package: ", pkg, " - NNS Optimization")
            )
        }
    )
## Package: healthyR
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 21 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 4.06441815427408"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 21, 63 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.99997022059981"
## [1] "BEST method = 'lin', seasonal.factor = c( 21, 63 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 3.99997022059981"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 21, 63 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 5.71904938021195"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 21, 63 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 5.71904938021195"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 21, 63 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 5.14228495373323"
## [1] "BEST method = 'both' PATH MEMBER = c( 21, 63 )"
## [1] "BEST both OBJECTIVE FUNCTION = 5.14228495373323"

## Package: healthyR.ai
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 7 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.60033053662806"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 7, 42 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.19460828948664"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 7, 42, 49 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.93008969213022"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 7, 42, 49, 63 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.58776659762755"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 7, 42, 49, 63, 98 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.51456616972992"
## [1] "BEST method = 'lin', seasonal.factor = c( 7, 42, 49, 63, 98 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 2.51456616972992"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 7, 42, 49, 63, 98 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 12.0371882649282"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 7, 42, 49, 63, 98 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 12.0371882649282"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 7, 42, 49, 63, 98 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 5.34961924971309"
## [1] "BEST method = 'both' PATH MEMBER = c( 7, 42, 49, 63, 98 )"
## [1] "BEST both OBJECTIVE FUNCTION = 5.34961924971309"

## Package: healthyR.data
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.1150174215318"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77, 42 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.80398201202113"
## [1] "BEST method = 'lin', seasonal.factor = c( 77, 42 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 2.80398201202113"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 77, 42 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 2.47617737784653"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 77, 42 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 2.47617737784653"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 77, 42 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 2.37975545264338"
## [1] "BEST method = 'both' PATH MEMBER = c( 77, 42 )"
## [1] "BEST both OBJECTIVE FUNCTION = 2.37975545264338"

## Package: healthyR.ts
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 63 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.180961870352"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 63, 49 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.11402508580056"
## [1] "BEST method = 'lin', seasonal.factor = c( 63, 49 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 2.11402508580056"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 63, 49 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 14.348684603633"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 63, 49 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 14.348684603633"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 63, 49 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 5.58645665743536"
## [1] "BEST method = 'both' PATH MEMBER = c( 63, 49 )"
## [1] "BEST both OBJECTIVE FUNCTION = 5.58645665743536"

## Package: healthyverse
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 4.40572305802886"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77, 63 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.49730878545913"
## [1] "BEST method = 'lin', seasonal.factor = c( 77, 63 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 3.49730878545913"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 77, 63 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 4.79994825981482"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 77, 63 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 4.79994825981482"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 77, 63 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 4.11550241366429"
## [1] "BEST method = 'both' PATH MEMBER = c( 77, 63 )"
## [1] "BEST both OBJECTIVE FUNCTION = 4.11550241366429"

## Package: RandomWalker
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 2.04863313671662"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77, 49 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 1.87720402400082"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 77, 49, 42 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 1.78624622621924"
## [1] "BEST method = 'lin', seasonal.factor = c( 77, 49, 42 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 1.78624622621924"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 77, 49, 42 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 1.60227694331498"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 77, 49, 42 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 1.60227694331498"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 77, 49, 42 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 1.52631578009582"
## [1] "BEST method = 'both' PATH MEMBER = c( 77, 49, 42 )"
## [1] "BEST both OBJECTIVE FUNCTION = 1.52631578009582"

## Package: tidyAML
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 84 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 4.39880918004636"
## [1] "BEST method = 'lin', seasonal.factor = c( 84 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 4.39880918004636"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 84 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 2.82357455153159"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 84 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 2.82357455153159"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 84 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 3.29418925930975"
## [1] "BEST method = 'both' PATH MEMBER = c( 84 )"
## [1] "BEST both OBJECTIVE FUNCTION = 3.29418925930975"

## Package: TidyDensity
## [1] "CURRNET METHOD: lin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'lin' , seasonal.factor =  c( 63 ) ...)"
## [1] "CURRENT lin OBJECTIVE FUNCTION = 3.02132032187574"
## [1] "BEST method = 'lin', seasonal.factor = c( 63 )"
## [1] "BEST lin OBJECTIVE FUNCTION = 3.02132032187574"
## [1] "CURRNET METHOD: nonlin"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'nonlin' , seasonal.factor =  c( 63 ) ...)"
## [1] "CURRENT nonlin OBJECTIVE FUNCTION = 9.59992274536936"
## [1] "BEST method = 'nonlin' PATH MEMBER = c( 63 )"
## [1] "BEST nonlin OBJECTIVE FUNCTION = 9.59992274536936"
## [1] "CURRNET METHOD: both"
## [1] "COPY LATEST PARAMETERS DIRECTLY FOR NNS.ARMA() IF ERROR:"
## [1] "NNS.ARMA(... method =  'both' , seasonal.factor =  c( 63 ) ...)"
## [1] "CURRENT both OBJECTIVE FUNCTION = 5.60812282893831"
## [1] "BEST method = 'both' PATH MEMBER = c( 63 )"
## [1] "BEST both OBJECTIVE FUNCTION = 5.60812282893831"

## [[1]]
## NULL
## 
## [[2]]
## NULL
## 
## [[3]]
## NULL
## 
## [[4]]
## NULL
## 
## [[5]]
## NULL
## 
## [[6]]
## NULL
## 
## [[7]]
## NULL
## 
## [[8]]
## NULL

Pre-Processing

Now we are going to do some basic pre-processing.

data_padded_tbl <- base_data %>%
  pad_by_time(
    .date_var  = date,
    .pad_value = 0
  )

# Get log interval and standardization parameters
log_params  <- liv(data_padded_tbl$value, limit_lower = 0, offset = 1, silent = TRUE)
limit_lower <- log_params$limit_lower
limit_upper <- log_params$limit_upper
offset      <- log_params$offset

data_liv_tbl <- data_padded_tbl %>%
  # Get log interval transform
  mutate(value_trans = liv(value, limit_lower = 0, offset = 1, silent = TRUE)$log_scaled)

# Get Standardization Params
std_params <- standard_vec(data_liv_tbl$value_trans, silent = TRUE)
std_mean   <- std_params$mean
std_sd     <- std_params$sd

data_transformed_tbl <- data_liv_tbl %>%
  # get standardization
  mutate(value_trans = standard_vec(value_trans, silent = TRUE)$standard_scaled) %>%
  select(-value)

Since this is panel data we can follow one of two different modeling strategies. We can search for a global model in the panel data or we can use nested forecasting finding the best model for each of the time series. Since we only have 5 panels, we will use nested forecasting.

To do this we will use the nest_timeseries and split_nested_timeseries functions to create a nested tibble.

horizon <- 4*7

nested_data_tbl <- data_transformed_tbl %>%
    
    # 1. Extending: We'll predict n days into the future.
    extend_timeseries(
        .id_var        = package,
        .date_var      = date,
        .length_future = horizon
    ) %>%
    
    # 2. Nesting: We'll group by id, and create a future dataset
    #    that forecasts n days of extended data and
    #    an actual dataset that contains n*2 days
    nest_timeseries(
        .id_var        = package,
        .length_future = horizon
        #.length_actual = horizon*2
    ) %>%
    
   # 3. Splitting: We'll take the actual data and create splits
   #    for accuracy and confidence interval estimation of n das (test)
   #    and the rest is training data
    split_nested_timeseries(
        .length_test = horizon
    )

nested_data_tbl
## # A tibble: 8 × 4
##   package       .actual_data         .future_data      .splits          
##   <fct>         <list>               <list>            <list>           
## 1 healthyR.data <tibble [1,680 × 2]> <tibble [28 × 2]> <split [1652|28]>
## 2 healthyR      <tibble [1,674 × 2]> <tibble [28 × 2]> <split [1646|28]>
## 3 healthyR.ts   <tibble [1,618 × 2]> <tibble [28 × 2]> <split [1590|28]>
## 4 healthyverse  <tibble [1,588 × 2]> <tibble [28 × 2]> <split [1560|28]>
## 5 healthyR.ai   <tibble [1,413 × 2]> <tibble [28 × 2]> <split [1385|28]>
## 6 TidyDensity   <tibble [1,264 × 2]> <tibble [28 × 2]> <split [1236|28]>
## 7 tidyAML       <tibble [872 × 2]>   <tibble [28 × 2]> <split [844|28]> 
## 8 RandomWalker  <tibble [294 × 2]>   <tibble [28 × 2]> <split [266|28]>

Now it is time to make some recipes and models using the modeltime workflow.

Modeltime Workflow

Recipe Object

recipe_base <- recipe(
  value_trans ~ date
  , data = extract_nested_test_split(nested_data_tbl)
  )

recipe_base

recipe_date <- recipe_base %>%
    step_mutate(date = as.numeric(date))

Models

# Models ------------------------------------------------------------------

# Auto ARIMA --------------------------------------------------------------

model_spec_arima_no_boost <- arima_reg() %>%
  set_engine(engine = "auto_arima")

wflw_auto_arima <- workflow() %>%
  add_recipe(recipe = recipe_base) %>%
  add_model(model_spec_arima_no_boost)

# NNETAR ------------------------------------------------------------------

model_spec_nnetar <- nnetar_reg(
  mode              = "regression"
  , seasonal_period = "auto"
) %>%
  set_engine("nnetar")

wflw_nnetar <- workflow() %>%
  add_recipe(recipe = recipe_base) %>%
  add_model(model_spec_nnetar)

# TSLM --------------------------------------------------------------------

model_spec_lm <- linear_reg() %>%
  set_engine("lm")

wflw_lm <- workflow() %>%
  add_recipe(recipe = recipe_base) %>%
  add_model(model_spec_lm)

# MARS --------------------------------------------------------------------

model_spec_mars <- mars(mode = "regression") %>%
  set_engine("earth")

wflw_mars <- workflow() %>%
  add_recipe(recipe = recipe_base) %>%
  add_model(model_spec_mars)

Nested Modeltime Tables

nested_modeltime_tbl <- modeltime_nested_fit(
  # Nested Data
  nested_data = nested_data_tbl,
   control = control_nested_fit(
     verbose = TRUE,
     allow_par = FALSE
   ),
  # Add workflows
  wflw_auto_arima,
  wflw_lm,
  wflw_mars,
  wflw_nnetar
)
nested_modeltime_tbl <- nested_modeltime_tbl[!is.na(nested_modeltime_tbl$package),]

Model Accuracy

nested_modeltime_tbl %>%
  extract_nested_test_accuracy() %>%
  filter(!is.na(package)) %>%
  knitr::kable()
package .model_id .model_desc .type mae mape mase smape rmse rsq
healthyR.data 1 ARIMA Test 0.6387831 121.52354 0.8043779 124.99035 0.7748652 0.0066078
healthyR.data 2 LM Test 0.6428732 127.06714 0.8095284 119.11102 0.7833459 0.0178960
healthyR.data 3 NULL NA NA NA NA NA NA NA
healthyR.data 4 NNAR Test 0.7023367 106.53792 0.8844069 191.94467 0.8212247 0.0075983
healthyR 1 ARIMA Test 0.7165756 151.03138 0.7549643 151.49377 0.9424499 0.0212405
healthyR 2 LM Test 0.7007660 100.86055 0.7383077 152.03003 0.9476467 0.0252489
healthyR 3 NULL NA NA NA NA NA NA NA
healthyR 4 NNAR Test 0.7072660 115.89929 0.7451560 149.91539 0.9495003 0.0012760
healthyR.ts 1 ARIMA Test 0.8794214 138.80343 0.7119328 162.66473 1.1412892 0.0060599
healthyR.ts 2 LM Test 0.8647180 156.47097 0.7000297 139.51937 1.1164574 0.0786569
healthyR.ts 3 NULL NA NA NA NA NA NA NA
healthyR.ts 4 NNAR Test 0.8357687 96.20768 0.6765938 174.71452 1.1226136 0.0893112
healthyverse 1 ARIMA Test 0.6686801 228.61384 0.7549952 90.62072 0.8515577 0.0014272
healthyverse 2 LM Test 0.6673951 232.01775 0.7535444 90.31555 0.8477696 0.0087579
healthyverse 3 NULL NA NA NA NA NA NA NA
healthyverse 4 NNAR Test 0.6570521 139.09648 0.7418662 101.32494 0.8665181 0.0218361
healthyR.ai 1 ARIMA Test 0.6284083 104.63595 0.7283585 142.86817 0.7779658 0.0001081
healthyR.ai 2 LM Test 0.6252170 101.68148 0.7246596 143.54901 0.7752920 0.0015936
healthyR.ai 3 NULL NA NA NA NA NA NA NA
healthyR.ai 4 NNAR Test 0.6282327 104.29692 0.7281549 143.41718 0.7739091 0.0048857
TidyDensity 1 ARIMA Test 0.4972813 85.25293 0.7161799 107.17167 0.7142283 0.0123547
TidyDensity 2 LM Test 0.4793384 126.22609 0.6903387 82.28127 0.6872720 0.0127604
TidyDensity 3 NULL NA NA NA NA NA NA NA
TidyDensity 4 NNAR Test 0.5424263 91.17799 0.7811973 124.34279 0.7490766 0.0019546
tidyAML 1 ARIMA Test 0.5796674 140.11576 0.8061651 89.87722 0.7417726 0.0176508
tidyAML 2 LM Test 0.5947299 165.19158 0.8271131 89.56647 0.7424083 0.0615052
tidyAML 3 NULL NA NA NA NA NA NA NA
tidyAML 4 NNAR Test 0.5807568 167.80904 0.8076802 87.54036 0.7223793 0.1041650
RandomWalker 1 ARIMA Test 1.0605624 106.27020 0.6520745 155.27585 1.2565860 0.0246102
RandomWalker 2 LM Test 1.1015392 100.44640 0.6772686 179.26902 1.2569323 0.0489512
RandomWalker 3 NULL NA NA NA NA NA NA NA
RandomWalker 4 NNAR Test 1.0495618 133.10017 0.6453109 140.97182 1.1989081 0.1292908

Plot Models

nested_modeltime_tbl %>%
  extract_nested_test_forecast() %>%
  group_by(package) %>%
  plot_modeltime_forecast(
    .interactive = FALSE,
    .conf_interval_show  = FALSE,
    .facet_scales = "free"
  ) +
  theme_minimal() +
  theme(legend.position = "bottom")

Best Model

best_nested_modeltime_tbl <- nested_modeltime_tbl %>%
  modeltime_nested_select_best(
    metric = "rmse",
    minimize = TRUE,
    filter_test_forecasts = TRUE
  )

best_nested_modeltime_tbl %>%
  extract_nested_best_model_report()
## # Nested Modeltime Table
## 

## # A tibble: 8 × 10
##   package      .model_id .model_desc .type   mae  mape  mase smape  rmse     rsq
##   <fct>            <int> <chr>       <chr> <dbl> <dbl> <dbl> <dbl> <dbl>   <dbl>
## 1 healthyR.da…         1 ARIMA       Test  0.639  122. 0.804 125.  0.775 0.00661
## 2 healthyR             1 ARIMA       Test  0.717  151. 0.755 151.  0.942 0.0212 
## 3 healthyR.ts          2 LM          Test  0.865  156. 0.700 140.  1.12  0.0787 
## 4 healthyverse         2 LM          Test  0.667  232. 0.754  90.3 0.848 0.00876
## 5 healthyR.ai          4 NNAR        Test  0.628  104. 0.728 143.  0.774 0.00489
## 6 TidyDensity          2 LM          Test  0.479  126. 0.690  82.3 0.687 0.0128 
## 7 tidyAML              4 NNAR        Test  0.581  168. 0.808  87.5 0.722 0.104  
## 8 RandomWalker         4 NNAR        Test  1.05   133. 0.645 141.  1.20  0.129
best_nested_modeltime_tbl %>%
  extract_nested_test_forecast() %>%
  #filter(!is.na(.model_id)) %>%
  group_by(package) %>%
  plot_modeltime_forecast(
    .interactive = FALSE,
    .conf_interval_alpha = 0.2,
    .facet_scales = "free"
  ) +
  theme_minimal() +
  theme(legend.position = "bottom")

Refitting and Future Forecast

Now that we have the best models, we can make our future forecasts.

nested_modeltime_refit_tbl <- best_nested_modeltime_tbl %>%
    modeltime_nested_refit(
        control = control_nested_refit(verbose = TRUE)
    )
nested_modeltime_refit_tbl
## # Nested Modeltime Table
## 

## # A tibble: 8 × 5
##   package       .actual_data .future_data .splits           .modeltime_tables 
##   <fct>         <list>       <list>       <list>            <list>            
## 1 healthyR.data <tibble>     <tibble>     <split [1652|28]> <mdl_tm_t [1 × 5]>
## 2 healthyR      <tibble>     <tibble>     <split [1646|28]> <mdl_tm_t [1 × 5]>
## 3 healthyR.ts   <tibble>     <tibble>     <split [1590|28]> <mdl_tm_t [1 × 5]>
## 4 healthyverse  <tibble>     <tibble>     <split [1560|28]> <mdl_tm_t [1 × 5]>
## 5 healthyR.ai   <tibble>     <tibble>     <split [1385|28]> <mdl_tm_t [1 × 5]>
## 6 TidyDensity   <tibble>     <tibble>     <split [1236|28]> <mdl_tm_t [1 × 5]>
## 7 tidyAML       <tibble>     <tibble>     <split [844|28]>  <mdl_tm_t [1 × 5]>
## 8 RandomWalker  <tibble>     <tibble>     <split [266|28]>  <mdl_tm_t [1 × 5]>
nested_modeltime_refit_tbl %>%
  extract_nested_future_forecast() %>%
  mutate(across(.value:.conf_hi, .fns = ~ standard_inv_vec(
    x    = .,
    mean = std_mean,
    sd   = std_sd
  )$standard_inverse_value)) %>%
  mutate(across(.value:.conf_hi, .fns = ~ liiv(
    x = .,
    limit_lower = limit_lower,
    limit_upper = limit_upper,
    offset      = offset
  )$rescaled_v)) %>%
  group_by(package) %>%
  plot_modeltime_forecast(
    .interactive = FALSE,
    .conf_interval_alpha = 0.2,
    .facet_scales = "free"
  ) +
  theme_minimal() +
  theme(legend.position = "bottom")