Replace Chronbachs Aplha with Holt Winters Alpha Function

[ron4]

SCRIPT 1

Question:

How do I get the Holtwinters Alpha code in the below script and replace the Chronsbachs Alpha?

SCRIPT 1

read_file(sales1)

library(tidyverse)

library(psy)

#Number of rows before to take into account

rolling = 2

sales1 <- sales::sales(

~date, ~sales,)

#Lag

sales1 = sales1 %>% mutate(lagsales = lag(sales))

#Rolling Chronbachs Alpha.:

sales1$alpha = c(

rep(NA, rolling),

map_dbl((rolling + 1):nrow(sales1), function(x){

cronbach(sales1 %>% select(sales, lagsales) %>% slice((x-rolling):x))$alpha

})

)

sales1

extract from Sales1 table

Date	sales
03-01-2017	40
04-01-2017	2
05-01-2017	2
06-01-2017	2
07-01-2017	30
08-01-2017	2
01-02-2017	9
02-02-2017	5
03-02-2017	65
04-02-2017	3
05-02-2017	65
06-02-2017	1
07-02-2017	11
08-02-2017	9
01-03-2017	21
02-03-2017	65
03-03-2017	5
04-03-2017	10
05-03-2017	40
06-03-2017	2
07-03-2017	2
08-03-2017	2
09-03-2017	30
01-04-2017	2