library(readxl)
library(forecast)
## Registered S3 method overwritten by 'quantmod':
##   method            from
##   as.zoo.data.frame zoo
serie.ivae <- read_excel("C:/Users/lupita nieto/Downloads/Practica  .xlsx",col_types = c("skip", "numeric"),
             skip = 0)
serie.ivae.ts<- ts(data = serie.ivae, start = c(2009,1),
                frequency = 12)
Yt<-serie.ivae.ts

Grafico De Serie Estacionaria

library(TSstudio)
library(forecast)

ts_plot(Yt,Xtitle= "Años/Meses")

Identificacion

Orden De Integracion

library(kableExtra)
library(magrittr)
d<-ndiffs(Yt)
D<-nsdiffs(Yt)
ordenes_integracion<-c(d,D)
names(ordenes_integracion)<-c("d","D")
ordenes_integracion %>% kable(caption = "Ordenes de Integracion") %>% kable_material()
Ordenes de Integracion
x
d 1
D 1
# Gráfico de la serie diferenciada
Yt %>%
  diff(lag=12,diffences=D) %>%
  diff(diffences=d) %>%
  ts_plot(title= "Yt estacionaria")

valores para (p,q) & (P,Q)

Yt %>%
  diff(lag=12,diffences=D) %>%
  diff(diffences=d) %>%
  ts_cor(lag.max = 36)

Estimacion Del Modelo

library(forecast)
library(ggthemes)
modelo_estimado<-Yt %>%
  Arima(order = c(0, 1, 0),
        seasonal = c(1, 1, 1))
summary(modelo_estimado)
## Series: . 
## ARIMA(0,1,0)(1,1,1)[12] 
## 
## Coefficients:
##          sar1     sma1
##       -0.1022  -0.7232
## s.e.   0.1266   0.1135
## 
## sigma^2 = 6.779:  log likelihood = -351.22
## AIC=708.43   AICc=708.6   BIC=717.38
## 
## Training set error measures:
##                      ME     RMSE     MAE        MPE     MAPE      MASE
## Training set 0.05202814 2.477766 1.68543 0.02782791 1.663587 0.4366552
##                    ACF1
## Training set 0.06837002
modelo_estimado %>% autoplot(type="both")+theme_solarized()

modelo_estimado %>% check_res(lag.max = 36)
## Warning: Ignoring 36 observations
## Warning: Ignoring 34 observations
## Warning: Ignoring 4 observations
library(forecast)

#Estimar el modelo
modeloHW<-HoltWinters(x = Yt,
                      seasonal = "multiplicative",
                      optim.start = c(0.9,0.9,0.9))
modeloHW
## Holt-Winters exponential smoothing with trend and multiplicative seasonal component.
## 
## Call:
## HoltWinters(x = Yt, seasonal = "multiplicative", optim.start = c(0.9,     0.9, 0.9))
## 
## Smoothing parameters:
##  alpha: 0.8472467
##  beta : 0
##  gamma: 1
## 
## Coefficients:
##            [,1]
## a   118.3719784
## b     0.1600947
## s1    0.9529095
## s2    1.0192349
## s3    1.0440936
## s4    0.9962326
## s5    1.0009929
## s6    0.9838373
## s7    0.9554392
## s8    1.0145286
## s9    1.0872315
## s10   0.9748891
## s11   0.9626701
## s12   1.0059813
#Generando el pronostico:
pronosticosMW<-forecast(object = modeloHW,h=12, level=c(0.95))
pronosticosMW
##          Point Forecast     Lo 95    Hi 95
## Apr 2022       112.9503 107.46492 118.4358
## May 2022       120.9752 113.57246 128.3779
## Jun 2022       124.0929 115.22236 132.9634
## Jul 2022       118.5640 108.86876 128.2592
## Aug 2022       119.2908 108.50116 130.0804
## Sep 2022       117.4038 105.81297 128.9947
## Oct 2022       114.1680 101.97016 126.3657
## Nov 2022       121.3911 107.66977 135.1125
## Dec 2022       130.2643 114.88360 145.6450
## Jan 2023       116.9603 102.34981 131.5708
## Feb 2023       115.6485 100.48405 130.8129
## Mar 2023       121.0126  83.19827 158.8270
#Gráfico comparativo
Yt_Sarima<-modelo_estimado$fitted
Yt_HW<-pronosticosMW$fitted
grafico_comparativo<-cbind(Yt, Yt_Sarima,Yt_HW)
ts_plot(grafico_comparativo)

Verificacion de sobre ajuste/sub ajuste

library(tsibble)
## 
## Attaching package: 'tsibble'
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, union
library(feasts)
## Loading required package: fabletools
## 
## Attaching package: 'fabletools'
## The following objects are masked from 'package:forecast':
## 
##     accuracy, forecast
library(fable)
library(fabletools)
library(tidyr)
## 
## Attaching package: 'tidyr'
## The following object is masked from 'package:magrittr':
## 
##     extract
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following object is masked from 'package:kableExtra':
## 
##     group_rows
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
a<-Yt %>% as_tsibble() %>% 
  model(arima_original=ARIMA(value ~ pdq(0, 1, 0) + PDQ(1, 1, 1)),
        arima_010_011 = ARIMA(value ~ pdq(0, 1, 0) + PDQ(0, 1, 1)),
        arima_010_110 = ARIMA(value ~ pdq(0, 1, 0) + PDQ(1, 1, 0)),
        arima_automatico=ARIMA(value,ic="bic",stepwise = FALSE)
  )
print(a)
## # A mable: 1 x 4
##              arima_original             arima_010_011             arima_010_110
##                     <model>                   <model>                   <model>
## 1 <ARIMA(0,1,0)(1,1,1)[12]> <ARIMA(0,1,0)(0,1,1)[12]> <ARIMA(0,1,0)(1,1,0)[12]>
## # … with 1 more variable: arima_automatico <model>
a %>% pivot_longer(everything(), names_to = "Model name",
                         values_to = "Orders") %>% glance() %>% 
  arrange(AICc) ->tabla
tabla
## # A tibble: 4 × 9
##   `Model name`     .model sigma2 log_lik   AIC  AICc   BIC ar_roots   ma_roots  
##   <chr>            <chr>   <dbl>   <dbl> <dbl> <dbl> <dbl> <list>     <list>    
## 1 arima_automatico Orders   6.13   -347.  702.  702.  714. <cpl [1]>  <cpl [12]>
## 2 arima_010_011    Orders   6.72   -352.  707.  707.  713. <cpl [0]>  <cpl [12]>
## 3 arima_original   Orders   6.78   -351.  708.  709.  717. <cpl [12]> <cpl [12]>
## 4 arima_010_110    Orders   7.99   -361.  726.  726.  731. <cpl [12]> <cpl [0]>

(Cross Validated)

library(forecast)
library(dplyr)
library(tsibble)
library(fable)
library(fabletools)
Yt<-Yt %>% as_tsibble() %>% rename(IVAE=value)

data.cross.validation<-Yt %>% 
  as_tsibble() %>% 
  stretch_tsibble(.init = 60,.step = 1)

TSCV<-data.cross.validation %>% 
model(ARIMA(IVAE ~ pdq(0, 1, 0) + PDQ(1, 1, 1))) %>% 
forecast(h=1) %>% accuracy(Yt)
## Warning: The future dataset is incomplete, incomplete out-of-sample data will be treated as missing. 
## 1 observation is missing at 2022 abr.
print(TSCV)
## # A tibble: 1 × 10
##   .model                .type     ME  RMSE   MAE     MPE  MAPE  MASE RMSSE  ACF1
##   <chr>                 <chr>  <dbl> <dbl> <dbl>   <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 ARIMA(IVAE ~ pdq(0, … Test  0.0506  2.94  2.09 0.00243  2.00 0.542 0.494 0.155