Tarea2 Seminario2:Series temporales usando analisis de intervención para la base Índice_De_Precios_al_Consumidor_Original(IPC)

Author

Katerin Raquel Zepeda Avila

# --- Cargar librerías ---
# 'forecast' para auto.arima y 'tsoutlier' para el análisis de intervención.
library(forecast)
Warning: package 'forecast' was built under R version 4.3.3
Registered S3 method overwritten by 'quantmod':
  method            from
  as.zoo.data.frame zoo 
library(tsoutliers)
Warning: package 'tsoutliers' was built under R version 4.3.3
library(haven)
Warning: package 'haven' was built under R version 4.3.2
# --- Cargar los datos ---

ipc_data <- read_sav("Índice_De_Precios_al_Consumidor_Original(IPC).sav")

head(ipc_data, 10)
# A tibble: 10 × 5
       periodo ipc_general YEAR_ MONTH_ DATE_   
         <dbl>       <dbl> <dbl>  <dbl> <chr>   
 1 13479004800        100   2009     12 DEC 2009
 2 13481683200        100.  2010      1 JAN 2010
 3 13484361600        101.  2010      2 FEB 2010
 4 13486780800        101.  2010      3 MAR 2010
 5 13489459200        101.  2010      4 APR 2010
 6 13492051200        100.  2010      5 MAY 2010
 7 13494729600        101.  2010      6 JUN 2010
 8 13497321600        101.  2010      7 JUL 2010
 9 13500000000        101.  2010      8 AUG 2010
10 13502678400        101.  2010      9 SEP 2010
# --- Crear el objeto de serie temporal (ts) ---
# Frecuencia mensual (12)

ipc_ts <- ts(ipc_data$ipc_general, start = c(2009, 12), frequency = 12)

# --- Visualizar la serie  ---
plot(ipc_ts, main="Índice_De_Precios_al_Consumidor (IPC) (2009-2025)", 
     ylab="IPC", xlab="Año")

El grafico nos muestra una tendencia que es de forma creciente, lo que nos indica que los precios han aumentado conforme al tiempo, en otras palabras es que a existico una inflcacion en los precios.

Tmpoco se observan caidas de forma brusca, si no que periodos con mayor o menor crecimiento.

El nivel genarl de precios (IPC) a aumentado de forma sostenida entre los año 2009 y 2025

Existe lo que es una aceleracion notable al rededor del año 2021 y 2022 lo que refleja un periodo de inflacion fuerte

En los años 2024 y 2025 vemos que se estabiliza.

# --- Encontrar el mejor modelo ARIMA automáticamente ---

# Forzamos la diferenciación (d=1, D=1) que sabemos que es necesaria.
# 'stepwise=FALSE' y 'approximation=FALSE' hacen la búsqueda más exhaustiva.

auto_model <- auto.arima(ipc_ts, 
                         d = 1, D = 1, 
                         stepwise = FALSE, 
                         approximation = FALSE, 
                         trace = TRUE)

 ARIMA(0,1,0)(0,1,0)[12]                    : 325.597
 ARIMA(0,1,0)(0,1,1)[12]                    : Inf
 ARIMA(0,1,0)(0,1,2)[12]                    : Inf
 ARIMA(0,1,0)(1,1,0)[12]                    : 305.6389
 ARIMA(0,1,0)(1,1,1)[12]                    : Inf
 ARIMA(0,1,0)(1,1,2)[12]                    : Inf
 ARIMA(0,1,0)(2,1,0)[12]                    : 286.4624
 ARIMA(0,1,0)(2,1,1)[12]                    : Inf
 ARIMA(0,1,0)(2,1,2)[12]                    : Inf
 ARIMA(0,1,1)(0,1,0)[12]                    : 301.7673
 ARIMA(0,1,1)(0,1,1)[12]                    : Inf
 ARIMA(0,1,1)(0,1,2)[12]                    : Inf
 ARIMA(0,1,1)(1,1,0)[12]                    : 283.5079
 ARIMA(0,1,1)(1,1,1)[12]                    : Inf
 ARIMA(0,1,1)(1,1,2)[12]                    : Inf
 ARIMA(0,1,1)(2,1,0)[12]                    : 262.5795
 ARIMA(0,1,1)(2,1,1)[12]                    : Inf
 ARIMA(0,1,1)(2,1,2)[12]                    : Inf
 ARIMA(0,1,2)(0,1,0)[12]                    : 303.0717
 ARIMA(0,1,2)(0,1,1)[12]                    : Inf
 ARIMA(0,1,2)(0,1,2)[12]                    : Inf
 ARIMA(0,1,2)(1,1,0)[12]                    : 285.1454
 ARIMA(0,1,2)(1,1,1)[12]                    : Inf
 ARIMA(0,1,2)(1,1,2)[12]                    : Inf
 ARIMA(0,1,2)(2,1,0)[12]                    : 263.7744
 ARIMA(0,1,2)(2,1,1)[12]                    : Inf
 ARIMA(0,1,3)(0,1,0)[12]                    : 303.1345
 ARIMA(0,1,3)(0,1,1)[12]                    : Inf
 ARIMA(0,1,3)(0,1,2)[12]                    : Inf
 ARIMA(0,1,3)(1,1,0)[12]                    : 283.9923
 ARIMA(0,1,3)(1,1,1)[12]                    : Inf
 ARIMA(0,1,3)(2,1,0)[12]                    : 262.8816
 ARIMA(0,1,4)(0,1,0)[12]                    : 305.2214
 ARIMA(0,1,4)(0,1,1)[12]                    : Inf
 ARIMA(0,1,4)(1,1,0)[12]                    : 286.1065
 ARIMA(0,1,5)(0,1,0)[12]                    : 304.4877
 ARIMA(1,1,0)(0,1,0)[12]                    : 300.6832
 ARIMA(1,1,0)(0,1,1)[12]                    : Inf
 ARIMA(1,1,0)(0,1,2)[12]                    : Inf
 ARIMA(1,1,0)(1,1,0)[12]                    : 282.1303
 ARIMA(1,1,0)(1,1,1)[12]                    : Inf
 ARIMA(1,1,0)(1,1,2)[12]                    : Inf
 ARIMA(1,1,0)(2,1,0)[12]                    : 260.6352
 ARIMA(1,1,0)(2,1,1)[12]                    : Inf
 ARIMA(1,1,0)(2,1,2)[12]                    : Inf
 ARIMA(1,1,1)(0,1,0)[12]                    : 302.5242
 ARIMA(1,1,1)(0,1,1)[12]                    : Inf
 ARIMA(1,1,1)(0,1,2)[12]                    : Inf
 ARIMA(1,1,1)(1,1,0)[12]                    : 284.2218
 ARIMA(1,1,1)(1,1,1)[12]                    : Inf
 ARIMA(1,1,1)(1,1,2)[12]                    : Inf
 ARIMA(1,1,1)(2,1,0)[12]                    : 262.7438
 ARIMA(1,1,1)(2,1,1)[12]                    : Inf
 ARIMA(1,1,2)(0,1,0)[12]                    : 304.4039
 ARIMA(1,1,2)(0,1,1)[12]                    : Inf
 ARIMA(1,1,2)(0,1,2)[12]                    : Inf
 ARIMA(1,1,2)(1,1,0)[12]                    : 283.5358
 ARIMA(1,1,2)(1,1,1)[12]                    : Inf
 ARIMA(1,1,2)(2,1,0)[12]                    : 261.7479
 ARIMA(1,1,3)(0,1,0)[12]                    : 305.2435
 ARIMA(1,1,3)(0,1,1)[12]                    : Inf
 ARIMA(1,1,3)(1,1,0)[12]                    : 286.1176
 ARIMA(1,1,4)(0,1,0)[12]                    : Inf
 ARIMA(2,1,0)(0,1,0)[12]                    : 302.5787
 ARIMA(2,1,0)(0,1,1)[12]                    : Inf
 ARIMA(2,1,0)(0,1,2)[12]                    : Inf
 ARIMA(2,1,0)(1,1,0)[12]                    : 284.2235
 ARIMA(2,1,0)(1,1,1)[12]                    : Inf
 ARIMA(2,1,0)(1,1,2)[12]                    : Inf
 ARIMA(2,1,0)(2,1,0)[12]                    : Inf
 ARIMA(2,1,0)(2,1,1)[12]                    : Inf
 ARIMA(2,1,1)(0,1,0)[12]                    : Inf
 ARIMA(2,1,1)(0,1,1)[12]                    : Inf
 ARIMA(2,1,1)(0,1,2)[12]                    : Inf
 ARIMA(2,1,1)(1,1,0)[12]                    : Inf
 ARIMA(2,1,1)(1,1,1)[12]                    : Inf
 ARIMA(2,1,1)(2,1,0)[12]                    : Inf
 ARIMA(2,1,2)(0,1,0)[12]                    : 306.1265
 ARIMA(2,1,2)(0,1,1)[12]                    : Inf
 ARIMA(2,1,2)(1,1,0)[12]                    : 285.0538
 ARIMA(2,1,3)(0,1,0)[12]                    : Inf
 ARIMA(3,1,0)(0,1,0)[12]                    : 304.4386
 ARIMA(3,1,0)(0,1,1)[12]                    : Inf
 ARIMA(3,1,0)(0,1,2)[12]                    : Inf
 ARIMA(3,1,0)(1,1,0)[12]                    : 284.2149
 ARIMA(3,1,0)(1,1,1)[12]                    : Inf
 ARIMA(3,1,0)(2,1,0)[12]                    : 264.0858
 ARIMA(3,1,1)(0,1,0)[12]                    : 306.6901
 ARIMA(3,1,1)(0,1,1)[12]                    : Inf
 ARIMA(3,1,1)(1,1,0)[12]                    : 285.9126
 ARIMA(3,1,2)(0,1,0)[12]                    : Inf
 ARIMA(4,1,0)(0,1,0)[12]                    : 304.613
 ARIMA(4,1,0)(0,1,1)[12]                    : Inf
 ARIMA(4,1,0)(1,1,0)[12]                    : 285.9764
 ARIMA(4,1,1)(0,1,0)[12]                    : 306.7461
 ARIMA(5,1,0)(0,1,0)[12]                    : 306.715



 Best model: ARIMA(1,1,0)(2,1,0)[12]                    
# Mostrar AIC y BIC
aic_value <- AIC(auto_model)
bic_value <- BIC(auto_model)

cat("AIC:", aic_value, "\n")
AIC: 260.4013 
cat("BIC:", bic_value, "\n")
BIC: 273.0832 

Para ARIMA (1,1,0) que es la parte no estacional:

AR(1) : un término autorregresivo.

d=1 : una diferencia no estacional.

MA(0) : no hay término de media móvil.

Para SARIMA (2,1,0)[12] que es la parte estacional con periodo 12 (mensual):

SAR(2) : dos términos autorregresivos estacionales.

D=1 : una diferencia estacional.

SMA(0) : no hay término estacional de media móvil.

AIC: 260.4013 y BIC: 273.0832: Ambos valores son relativamente bajos, lo que sugiere que el modelo se ajusta bien a los datos.

# --- Mostrar el modelo seleccionado ---
print(auto_model)
Series: ipc_ts 
ARIMA(1,1,0)(2,1,0)[12] 

Coefficients:
         ar1     sar1     sar2
      0.3833  -0.4603  -0.3987
s.e.  0.0696   0.0753   0.0769

sigma^2 = 0.2427:  log likelihood = -126.2
AIC=260.4   AICc=260.64   BIC=273.08

Es la varianza de los residuos (el error del modelo) fue de 0.2427 que indica que, en promedio, el error de predicción es relativamente bajo respecto a la escala de la serie.

Los coeficientes son significativos, ya que indica que esos patrones sí existen en la serie. El valor de AIC/BIC te servirá para contrastarlo con otros modelos y decidir si este es el más adecuado.

AIC = 260.4, AICC = 260.64 y BIC = 273.08

Se usan para comparar los modelos: cuanto más bajo, mejor.

# graficar la serie temporal
TSstudio::ts_plot(ipc_ts)
# --- Dejar que auto.arima() determine d y D automáticamente ---
# Al omitir 'd' y 'D', la función usará pruebas estadísticas.
# 'trace=TRUE' nos mostrará lo que está haciendo.



# R encuentra el ARIMA óptimo de manera totalmente automática, sin que tengamoa  que especificar d ni D.


auto_model_fully_automatic <- auto.arima(ipc_ts,
                         stepwise = FALSE, 
                         approximation = FALSE, 
                         trace = TRUE)

 ARIMA(0,1,0)                               : 268.4105
 ARIMA(0,1,0)            with drift         : 248.2887
 ARIMA(0,1,0)(0,0,1)[12]                    : 256.4821
 ARIMA(0,1,0)(0,0,1)[12] with drift         : 243.7612
 ARIMA(0,1,0)(0,0,2)[12]                    : 258.5093
 ARIMA(0,1,0)(0,0,2)[12] with drift         : 244.1312
 ARIMA(0,1,0)(1,0,0)[12]                    : 257.6958
 ARIMA(0,1,0)(1,0,0)[12] with drift         : 245.2457
 ARIMA(0,1,0)(1,0,1)[12]                    : 258.5117
 ARIMA(0,1,0)(1,0,1)[12] with drift         : 244.9341
 ARIMA(0,1,0)(1,0,2)[12]                    : 260.5987
 ARIMA(0,1,0)(1,0,2)[12] with drift         : 245.9913
 ARIMA(0,1,0)(2,0,0)[12]                    : 258.7892
 ARIMA(0,1,0)(2,0,0)[12] with drift         : 243.1204
 ARIMA(0,1,0)(2,0,1)[12]                    : 260.5817
 ARIMA(0,1,0)(2,0,1)[12] with drift         : 245.2313
 ARIMA(0,1,0)(2,0,2)[12]                    : 262.3834
 ARIMA(0,1,0)(2,0,2)[12] with drift         : Inf
 ARIMA(0,1,1)                               : 242.9684
 ARIMA(0,1,1)            with drift         : 231.3953
 ARIMA(0,1,1)(0,0,1)[12]                    : 230.2924
 ARIMA(0,1,1)(0,0,1)[12] with drift         : 223.8091
 ARIMA(0,1,1)(0,0,2)[12]                    : 231.9045
 ARIMA(0,1,1)(0,0,2)[12] with drift         : 224.175
 ARIMA(0,1,1)(1,0,0)[12]                    : 232.4118
 ARIMA(0,1,1)(1,0,0)[12] with drift         : 225.9742
 ARIMA(0,1,1)(1,0,1)[12]                    : 231.899
 ARIMA(0,1,1)(1,0,1)[12] with drift         : 224.6689
 ARIMA(0,1,1)(1,0,2)[12]                    : 234.0051
 ARIMA(0,1,1)(1,0,2)[12] with drift         : 226.2312
 ARIMA(0,1,1)(2,0,0)[12]                    : 232.5461
 ARIMA(0,1,1)(2,0,0)[12] with drift         : 223.9232
 ARIMA(0,1,1)(2,0,1)[12]                    : 234.0005
 ARIMA(0,1,1)(2,0,1)[12] with drift         : 225.9323
 ARIMA(0,1,1)(2,0,2)[12]                    : Inf
 ARIMA(0,1,1)(2,0,2)[12] with drift         : 228.0083
 ARIMA(0,1,2)                               : 244.4305
 ARIMA(0,1,2)            with drift         : 233.4781
 ARIMA(0,1,2)(0,0,1)[12]                    : 231.5816
 ARIMA(0,1,2)(0,0,1)[12] with drift         : 225.7814
 ARIMA(0,1,2)(0,0,2)[12]                    : 233.1228
 ARIMA(0,1,2)(0,0,2)[12] with drift         : 226.1878
 ARIMA(0,1,2)(1,0,0)[12]                    : 233.8445
 ARIMA(0,1,2)(1,0,0)[12] with drift         : 227.9888
 ARIMA(0,1,2)(1,0,1)[12]                    : 233.1203
 ARIMA(0,1,2)(1,0,1)[12] with drift         : 226.6588
 ARIMA(0,1,2)(1,0,2)[12]                    : 235.2456
 ARIMA(0,1,2)(1,0,2)[12] with drift         : 228.2785
 ARIMA(0,1,2)(2,0,0)[12]                    : 233.8313
 ARIMA(0,1,2)(2,0,0)[12] with drift         : 225.9771
 ARIMA(0,1,2)(2,0,1)[12]                    : 235.239
 ARIMA(0,1,2)(2,0,1)[12] with drift         : 227.9905
 ARIMA(0,1,3)                               : 239.391
 ARIMA(0,1,3)            with drift         : 231.1031
 ARIMA(0,1,3)(0,0,1)[12]                    : 229.457
 ARIMA(0,1,3)(0,0,1)[12] with drift         : 225.0055
 ARIMA(0,1,3)(0,0,2)[12]                    : 231.0974
 ARIMA(0,1,3)(0,0,2)[12] with drift         : 225.7762
 ARIMA(0,1,3)(1,0,0)[12]                    : 231.2124
 ARIMA(0,1,3)(1,0,0)[12] with drift         : 226.7413
 ARIMA(0,1,3)(1,0,1)[12]                    : 231.1118
 ARIMA(0,1,3)(1,0,1)[12] with drift         : 226.1594
 ARIMA(0,1,3)(2,0,0)[12]                    : 231.5426
 ARIMA(0,1,3)(2,0,0)[12] with drift         : 225.5244
 ARIMA(0,1,4)                               : 240.8775
 ARIMA(0,1,4)            with drift         : 233.1605
 ARIMA(0,1,4)(0,0,1)[12]                    : 231.512
 ARIMA(0,1,4)(0,0,1)[12] with drift         : 227.1581
 ARIMA(0,1,4)(1,0,0)[12]                    : 233.2083
 ARIMA(0,1,4)(1,0,0)[12] with drift         : 228.8979
 ARIMA(0,1,5)                               : 241.5303
 ARIMA(0,1,5)            with drift         : 234.604
 ARIMA(1,1,0)                               : 239.8036
 ARIMA(1,1,0)            with drift         : 231.2853
 ARIMA(1,1,0)(0,0,1)[12]                    : 227.9753
 ARIMA(1,1,0)(0,0,1)[12] with drift         : 223.5404
 ARIMA(1,1,0)(0,0,2)[12]                    : 229.4717
 ARIMA(1,1,0)(0,0,2)[12] with drift         : 224.1526
 ARIMA(1,1,0)(1,0,0)[12]                    : 230.0899
 ARIMA(1,1,0)(1,0,0)[12] with drift         : 225.6312
 ARIMA(1,1,0)(1,0,1)[12]                    : 229.4881
 ARIMA(1,1,0)(1,0,1)[12] with drift         : 224.5412
 ARIMA(1,1,0)(1,0,2)[12]                    : 231.5774
 ARIMA(1,1,0)(1,0,2)[12] with drift         : 226.2447
 ARIMA(1,1,0)(2,0,0)[12]                    : 230.0623
 ARIMA(1,1,0)(2,0,0)[12] with drift         : 223.9893
 ARIMA(1,1,0)(2,0,1)[12]                    : 231.5578
 ARIMA(1,1,0)(2,0,1)[12] with drift         : 225.9507
 ARIMA(1,1,0)(2,0,2)[12]                    : 233.6725
 ARIMA(1,1,0)(2,0,2)[12] with drift         : 227.9758
 ARIMA(1,1,1)                               : 234.6954
 ARIMA(1,1,1)            with drift         : Inf
 ARIMA(1,1,1)(0,0,1)[12]                    : 229.9967
 ARIMA(1,1,1)(0,0,1)[12] with drift         : 225.5132
 ARIMA(1,1,1)(0,0,2)[12]                    : 231.5444
 ARIMA(1,1,1)(0,0,2)[12] with drift         : 225.9995
 ARIMA(1,1,1)(1,0,0)[12]                    : 231.884
 ARIMA(1,1,1)(1,0,0)[12] with drift         : 227.7
 ARIMA(1,1,1)(1,0,1)[12]                    : 231.5675
 ARIMA(1,1,1)(1,0,1)[12] with drift         : 226.4302
 ARIMA(1,1,1)(1,0,2)[12]                    : 233.6754
 ARIMA(1,1,1)(1,0,2)[12] with drift         : 228.1057
 ARIMA(1,1,1)(2,0,0)[12]                    : 232.046
 ARIMA(1,1,1)(2,0,0)[12] with drift         : 225.8393
 ARIMA(1,1,1)(2,0,1)[12]                    : 233.6486
 ARIMA(1,1,1)(2,0,1)[12] with drift         : 227.8276
 ARIMA(1,1,2)                               : 230.8038
 ARIMA(1,1,2)            with drift         : 229.9601
 ARIMA(1,1,2)(0,0,1)[12]                    : 225.9051
 ARIMA(1,1,2)(0,0,1)[12] with drift         : 225.1139
 ARIMA(1,1,2)(0,0,2)[12]                    : 226.6804
 ARIMA(1,1,2)(0,0,2)[12] with drift         : 225.7042
 ARIMA(1,1,2)(1,0,0)[12]                    : 227.2755
 ARIMA(1,1,2)(1,0,0)[12] with drift         : 226.5852
 ARIMA(1,1,2)(1,0,1)[12]                    : 226.9552
 ARIMA(1,1,2)(1,0,1)[12] with drift         : 226.1239
 ARIMA(1,1,2)(2,0,0)[12]                    : 226.8006
 ARIMA(1,1,2)(2,0,0)[12] with drift         : 225.6001
 ARIMA(1,1,3)                               : 230.932
 ARIMA(1,1,3)            with drift         : 230.0292
 ARIMA(1,1,3)(0,0,1)[12]                    : 231.5024
 ARIMA(1,1,3)(0,0,1)[12] with drift         : 227.1583
 ARIMA(1,1,3)(1,0,0)[12]                    : 228.5755
 ARIMA(1,1,3)(1,0,0)[12] with drift         : 227.8451
 ARIMA(1,1,4)                               : 232.5778
 ARIMA(1,1,4)            with drift         : 231.7276
 ARIMA(2,1,0)                               : 241.2892
 ARIMA(2,1,0)            with drift         : 233.3728
 ARIMA(2,1,0)(0,0,1)[12]                    : 230.0369
 ARIMA(2,1,0)(0,0,1)[12] with drift         : 225.5947
 ARIMA(2,1,0)(0,0,2)[12]                    : 231.5664
 ARIMA(2,1,0)(0,0,2)[12] with drift         : 226.1517
 ARIMA(2,1,0)(1,0,0)[12]                    : 232.0885
 ARIMA(2,1,0)(1,0,0)[12] with drift         : 227.7297
 ARIMA(2,1,0)(1,0,1)[12]                    : 231.5855
 ARIMA(2,1,0)(1,0,1)[12] with drift         : 226.56
 ARIMA(2,1,0)(1,0,2)[12]                    : 233.6962
 ARIMA(2,1,0)(1,0,2)[12] with drift         : 228.2643
 ARIMA(2,1,0)(2,0,0)[12]                    : Inf
 ARIMA(2,1,0)(2,0,0)[12] with drift         : Inf
 ARIMA(2,1,0)(2,0,1)[12]                    : Inf
 ARIMA(2,1,0)(2,0,1)[12] with drift         : Inf
 ARIMA(2,1,1)                               : 232.2613
 ARIMA(2,1,1)            with drift         : 231.3886
 ARIMA(2,1,1)(0,0,1)[12]                    : 227.5575
 ARIMA(2,1,1)(0,0,1)[12] with drift         : 223.0912
 ARIMA(2,1,1)(0,0,2)[12]                    : 229.0463
 ARIMA(2,1,1)(0,0,2)[12] with drift         : 223.591
 ARIMA(2,1,1)(1,0,0)[12]                    : 229.9432
 ARIMA(2,1,1)(1,0,0)[12] with drift         : 225.4535
 ARIMA(2,1,1)(1,0,1)[12]                    : 228.577
 ARIMA(2,1,1)(1,0,1)[12] with drift         : 224.0186
 ARIMA(2,1,1)(2,0,0)[12]                    : Inf
 ARIMA(2,1,1)(2,0,0)[12] with drift         : 223.4511
 ARIMA(2,1,2)                               : 229.7121
 ARIMA(2,1,2)            with drift         : 228.8456
 ARIMA(2,1,2)(0,0,1)[12]                    : 226.9244
 ARIMA(2,1,2)(0,0,1)[12] with drift         : 226.0639
 ARIMA(2,1,2)(1,0,0)[12]                    : 227.8908
 ARIMA(2,1,2)(1,0,0)[12] with drift         : 227.1121
 ARIMA(2,1,3)                               : 231.8138
 ARIMA(2,1,3)            with drift         : 230.9883
 ARIMA(3,1,0)                               : 235.9541
 ARIMA(3,1,0)            with drift         : 230.9239
 ARIMA(3,1,0)(0,0,1)[12]                    : 229.3528
 ARIMA(3,1,0)(0,0,1)[12] with drift         : 225.8918
 ARIMA(3,1,0)(0,0,2)[12]                    : 231.0812
 ARIMA(3,1,0)(0,0,2)[12] with drift         : 226.8511
 ARIMA(3,1,0)(1,0,0)[12]                    : 230.5918
 ARIMA(3,1,0)(1,0,0)[12] with drift         : 227.3192
 ARIMA(3,1,0)(1,0,1)[12]                    : 231.141
 ARIMA(3,1,0)(1,0,1)[12] with drift         : 227.2345
 ARIMA(3,1,0)(2,0,0)[12]                    : 231.1935
 ARIMA(3,1,0)(2,0,0)[12] with drift         : 226.4926
 ARIMA(3,1,1)                               : 232.205
 ARIMA(3,1,1)            with drift         : 232.6697
 ARIMA(3,1,1)(0,0,1)[12]                    : 231.0712
 ARIMA(3,1,1)(0,0,1)[12] with drift         : 227.1181
 ARIMA(3,1,1)(1,0,0)[12]                    : 229.5269
 ARIMA(3,1,1)(1,0,0)[12] with drift         : 228.8258
 ARIMA(3,1,2)                               : 231.8149
 ARIMA(3,1,2)            with drift         : 230.9889
 ARIMA(4,1,0)                               : 237.7921
 ARIMA(4,1,0)            with drift         : 233.057
 ARIMA(4,1,0)(0,0,1)[12]                    : 231.4276
 ARIMA(4,1,0)(0,0,1)[12] with drift         : 227.6572
 ARIMA(4,1,0)(1,0,0)[12]                    : 232.704
 ARIMA(4,1,0)(1,0,0)[12] with drift         : 229.247
 ARIMA(4,1,1)                               : 233.8097
 ARIMA(4,1,1)            with drift         : 232.9414
 ARIMA(5,1,0)                               : 237.1583
 ARIMA(5,1,0)            with drift         : 233.7084



 Best model: ARIMA(2,1,1)(0,0,1)[12] with drift         
# Mostrar AIC y BIC
aic_value <- AIC(auto_model_fully_automatic)
bic_value <- BIC(auto_model_fully_automatic)

cat("AIC:", aic_value, "\n")  # Cat() función principal es imprimir texto y valores
AIC: 222.6271 
cat("BIC:", bic_value, "\n")
BIC: 242.0457 

Parte no estacional (2,1,1)

AR(2) : la serie depende de los 2 valores anteriores.

d=1 : se aplicó una diferencia para lograr estacionariedad.

MA(1) : la serie depende también de un error aleatorio en el período anterior.

Parte estacional (0,0,1) [12]

SAR(0) y D=0 : no hay parte autorregresiva estacional ni diferencia estacional.

SMA(1) : hay una media móvil estacional de orden 1 o que depende de un error 12 períodos antes.

[12] : el período estacional es 12 (lo usual en datos mensuales).

El valor de AIC es de 22.6271 y BIC es de 242.0457

# --- Mostrar el modelo seleccionado ---

print(auto_model_fully_automatic)
Series: ipc_ts 
ARIMA(2,1,1)(0,0,1)[12] with drift 

Coefficients:
          ar1     ar2     ma1    sma1   drift
      -0.5958  0.2747  0.9782  0.2713  0.1584
s.e.   0.0751  0.0731  0.0251  0.0812  0.0577

sigma^2 = 0.1831:  log likelihood = -105.31
AIC=222.63   AICc=223.09   BIC=242.05

No estacional (2,1,1):

ar1 = -0.5958, ar2 = 0.2747: la serie depende de los dos últimos rezagos.

ma1 = 0.9782: fuerte efecto de la media móvil (error del período anterior).

Estacional (0,0,1)[12]:

sma1 = 0.2713: hay un efecto de error cada 12 períodos (1 año).

with drift:

drift = 0.1584: la serie diferenciada muestra una tendencia positiva suave.

El modelo ARIMA(2,1,1)(0,0,1)[12] describe mucho mejor la serie ipc_ts que el modelo manual que so probó. Por lo tanto, conviene usar el automático para análisis y pronósticos.

modelo=tso(ipc_ts)
modelo
Series: ipc_ts 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1    sar2    LS17    LS71    TC169
      0.5204  0.2259  0.0175  2.5012  2.3887  -0.9304
s.e.  0.0637  0.0803  0.0822  0.2942  0.2879   0.2485

sigma^2 = 0.1071:  log likelihood = -54.18
AIC=122.37   AICc=122.99   BIC=145.02

Outliers:
  type ind    time coefhat  tstat
1   LS  17 2011:04  2.5012  8.502
2   LS  71 2015:10  2.3887  8.296
3   TC 169 2023:12 -0.9304 -3.744

La serie ipc_ts tiene dependencia en el tiempo (AR(1) + estacionalidad de 12 meses).

La tendencia se eliminó con una diferencia que hicimos.

Existen cambios estructurales permanentes (LS17 y LS71).

Existe un evento transitorio en el período 169 (TC169).

El ajuste es muy bueno (sigma^2 bajo y AIC/BIC reducidos).

plot(modelo)

ORIGINAL AND ADJUSTED SERIES

La línea azul (serie ajustada por el modelo ARIMA con outlers) sigue de cerca la gris(serie original) , lo que indica que el modelo ajusta muy bien la serie.

Cada punto rojo coincide con un salto o cambio importante en la serie. Esto confirma la presencia de los level shifts (LS) y transitory changes (TC) que el modelo identificó.

OUTLIER EFFECTS

Línea roja es la magnitud acumulada de los efectos de los outliers sobre la serie.

Escala vertical es el número de unidades de efecto que cada outlier agrega a la serie.

La línea sube en escalones: cada salto corresponde a un level shift (LS17, LS71).

El pequeño ajuste al final refleja un cambio transitorio (TC169) que no se mantiene, por eso la línea vuelve a estabilizarse.

Este panel muestra cómo los outliers modifican la serie original; sin ellos, el modelo no podría ajustarse tan bien.

# Crear una secuencia de números de fila para la condición
# filas <- 1:189  #189 datos (vector que va de 1 a 189)
filas <- 1:nrow(ipc_data)

# LS17: cambio permanente a partir de la observación 17
ipc_data$LS17 <- ifelse(filas >= 17, 1, 0)

# LS71: cambio permanente a partir de la observación 71
ipc_data$LS71 <- ifelse(filas >= 71, 1, 0)

# TC169: cambio transitorio en la observación 169
# Se marca solo en el punto exacto
ipc_data$TC169 <- ifelse(filas >= 169, 1, 0)
print(head(ipc_data))
# A tibble: 6 × 8
      periodo ipc_general YEAR_ MONTH_ DATE_     LS17  LS71 TC169
        <dbl>       <dbl> <dbl>  <dbl> <chr>    <dbl> <dbl> <dbl>
1 13479004800        100   2009     12 DEC 2009     0     0     0
2 13481683200        100.  2010      1 JAN 2010     0     0     0
3 13484361600        101.  2010      2 FEB 2010     0     0     0
4 13486780800        101.  2010      3 MAR 2010     0     0     0
5 13489459200        101.  2010      4 APR 2010     0     0     0
6 13492051200        100.  2010      5 MAY 2010     0     0     0
library(forecast)

serie1=ts(ipc_data,start = c(2009,12),frequency = 12)
library(tsoutliers)
plot(serie1)

EL LADO IZQUIERDO INDICA:

Las variables que la base de datos más la serie temporal.

período : un contador de observaciones, básicamente el índice de fila (crece linealmente).

ipc_general : la serie original del IPC (sube con el tiempo, y se nota la tendencia + cambios).

YEAR_ : el año correspondiente a cada dato (sube en escalones de 1 en 1 cada 12 meses).

MONTH_ : el mes (ciclo de 1 a 12 que se repite).

EL LADO DERECHO INDICA:

DATE_ : otra variable de fecha en la base, con estacionalidad mensual

LS17 : se activa en el dato 17 y vale 1 en adelante. Representa un cambio permanente en el nivel de la serie a partir de esa observación.

LS71 : se activa en el dato 71 y vale 1 en adelante. Otro cambio permanente, pero más adelante en la serie.

TC169 : vale 1 solo en la observación 169 y 0 en el resto. Representa un cambio transitorio (choque puntual que no dura).

# Modelo llamado modelo con ARIMA (1,1,0) (2,0,0) con AIC= 122.37   BIC= 145.02

#Interviniendo el outler 17
modelo1=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$LS17))

#Interviniendo el outler 71
modelo2=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$LS71))

#Interviniendo el outler 169
modelo3=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$TC169))

#Interviniendo el outler 17, 71,
modelo4=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$LS17, ipc_data$LS71))

#Interviniendo el outler 71, 169,
modelo5=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$LS71, ipc_data$TC169))

#Interviniendo el outler 71, 169,
modelo6=Arima(ipc_data$ipc_general,
              order = c(1,1,0),
              seasonal=list(order=c(2,0,0),period=12),
              xreg=cbind(ipc_data$LS17, ipc_data$LS71, ipc_data$TC169))
modelo1
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1     sar2    xreg
      0.3895  0.2759  -0.0219  2.5289
s.e.  0.0679  0.0741   0.0780  0.3610

sigma^2 = 0.1522:  log likelihood = -88.26
AIC=186.52   AICc=186.85   BIC=202.7
modelo2
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1     sar2    xreg
      0.4571  0.2733  -0.1201  2.2957
s.e.  0.0649  0.0761   0.0924  0.3480

sigma^2 = 0.1567:  log likelihood = -91.15
AIC=192.3   AICc=192.63   BIC=208.48
modelo3
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1     sar2     xreg
      0.4107  0.2714  -0.1408  -1.0727
s.e.  0.0671  0.0742   0.0837   0.3837

sigma^2 = 0.1856:  log likelihood = -107.1
AIC=224.21   AICc=224.53   BIC=240.39
modelo4
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1    sar2   xreg1   xreg2
      0.4935  0.2527  0.0506  2.5363  2.3832
s.e.  0.0646  0.0772  0.0846  0.3057  0.2982

sigma^2 = 0.1144:  log likelihood = -60.99
AIC=133.99   AICc=134.45   BIC=153.4
modelo5
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1     sar2   xreg1    xreg2
      0.4842  0.2584  -0.1470  2.2972  -1.0985
s.e.  0.0646  0.0773   0.0906  0.3358   0.3369

sigma^2 = 0.1491:  log likelihood = -85.99
AIC=183.97   AICc=184.44   BIC=203.39
modelo6
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1    sar2   xreg1   xreg2    xreg3
      0.5210  0.2307  0.0253  2.5063  2.3891  -1.0491
s.e.  0.0637  0.0799  0.0820  0.2942  0.2876   0.2837

sigma^2 = 0.1073:  log likelihood = -54.37
AIC=122.73   AICc=123.35   BIC=145.39

Al tener los 6 modelos creados para analizar cual modelo es el menor valor de AIC y BIC concluimos que el mejor modelo es “modelo6” con un valor de AIC = 122.73 y BIC= 145.39, estos valores de ese modelo es el menor de todos.

library(lmtest)
Warning: package 'lmtest' was built under R version 4.3.2
Loading required package: zoo
Warning: package 'zoo' was built under R version 4.3.2

Attaching package: 'zoo'
The following objects are masked from 'package:base':

    as.Date, as.Date.numeric
coeftest(modelo6)

z test of coefficients:

       Estimate Std. Error z value  Pr(>|z|)    
ar1    0.520987   0.063655  8.1846 2.732e-16 ***
sar1   0.230653   0.079908  2.8865 0.0038957 ** 
sar2   0.025345   0.081978  0.3092 0.7571971    
xreg1  2.506267   0.294232  8.5180 < 2.2e-16 ***
xreg2  2.389119   0.287620  8.3065 < 2.2e-16 ***
xreg3 -1.049063   0.283719 -3.6975 0.0002177 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

H0 : el coeficiente = 0 (no hay efecto significativo).

H1: el coeficiente ≠ 0 (sí tiene efecto significativo).

El modelo tiene varios coeficientes altamente significativos

El sar2 no es significativo

checkresiduals(modelo6)


    Ljung-Box test

data:  Residuals from Regression with ARIMA(1,1,0)(2,0,0)[12] errors
Q* = 10.398, df = 7, p-value = 0.1671

Model df: 3.   Total lags used: 10

H0: Los residuos son independientes (ruido blanco).

H1: Los residuos muestran autocorrelación significativa.

Si p_value > 0.05, no rechazamos H0.

Como mi p_value fue de 0.1671, esto es mayor que 0.05 por lo que no rechazamos la hipotesis nula por lo que los residuos son independientes y el modelo se ajusta bien y los residuos se estan comportando como ruido blanco.

PARA LOS GRAFICO TENEMOS QUE:

Los residuos no presentan tendencia (el gráfico superior).

No hay autocorrelación significativa (ACF dentro de los límites).

Los residuos siguen aproximadamente una distribución normal (histograma).

# resumen de métricas de desempeño del modelo ARIMA aplicado al conjunto de entrenamiento

accuracy(modelo6)
                     ME      RMSE       MAE        MPE      MAPE      MASE
Training set 0.04958185 0.3214601 0.2603451 0.04319565 0.2295182 0.7598956
                    ACF1
Training set -0.03066765
library(forecast)

xreg_future <- cbind(LS17 = ipc_data$LS17, LS71 = ipc_data$LS71,TC169 = ipc_data$TC169)

predicciones <- forecast(modelo6, h = 12, xreg = xreg_future)
Warning in forecast.forecast_ARIMA(modelo6, h = 12, xreg = xreg_future): xreg
contains different column names from the xreg used in training. Please check
that the regressors are in the same order.
predicciones
    Point Forecast    Lo 80    Hi 80    Lo 95    Hi 95
190       126.6526 126.2328 127.0724 126.0105 127.2947
191       126.4766 125.7125 127.2408 125.3079 127.6454
192       126.4036 125.3312 127.4761 124.7634 128.0438
193       126.3274 124.9823 127.6725 124.2703 128.3846
194       126.4277 124.8404 128.0150 124.0001 128.8553
195       126.4080 124.6032 128.2127 123.6478 129.1681
196       126.4476 124.4453 128.4500 123.3853 129.5100
197       126.4642 124.2804 128.6481 123.1243 129.8042
198       126.5021 124.1499 128.8543 122.9047 130.0995
199       126.6080 124.0983 129.1178 122.7697 130.4464
200       126.7166 124.0584 129.3747 122.6513 130.7819
201       126.5928 123.7940 129.3916 122.3124 130.8732
202       126.5073 123.5441 129.4704 121.9756 131.0390
203       126.4570 123.3221 129.5920 121.6625 131.2515
204       126.4374 123.1313 129.7435 121.3811 131.4936
205       126.4142 122.9412 129.8872 121.1027 131.7257
206       128.9550 125.3207 132.5893 123.3968 134.5132
207       128.9484 125.1586 132.7382 123.1524 134.7445
208       128.9621 125.0224 132.9019 122.9368 134.9874
209       128.9670 124.8826 133.0514 122.7204 135.2136
210       128.9793 124.7550 133.2035 122.5188 135.4397
211       129.0143 124.6546 133.3741 122.3467 135.6820
212       129.0503 124.5591 133.5414 122.1817 135.9188
213       129.0095 124.3908 133.6283 121.9457 136.0734
214       128.9819 124.2313 133.7326 121.7164 136.2474
215       128.9659 124.0830 133.8488 121.4981 136.4336
216       128.9595 123.9458 133.9732 121.2918 136.6273
217       128.9522 123.8101 134.0944 121.0880 136.8165
218       128.9627 123.6947 134.2308 120.9060 137.0195
219       128.9607 123.5695 134.3520 120.7155 137.2059
220       128.9649 123.4530 134.4767 120.5352 137.3945
221       128.9664 123.3365 134.5964 120.3562 137.5767
222       128.9702 123.2246 134.7159 120.1830 137.7574
223       128.9810 123.1219 134.8401 120.0203 137.9417
224       128.9920 123.0217 134.9624 119.8612 138.1229
225       128.9795 122.8999 135.0591 119.6816 138.2774
226       128.9710 122.7822 135.1598 119.5060 138.4359
227       128.9660 122.6689 135.2631 119.3355 138.5965
228       128.9640 122.5600 135.3680 119.1699 138.7581
229       128.9618 122.4523 135.4712 119.0064 138.9171
230       128.9651 122.3517 135.5784 118.8508 139.0793
231       128.9644 122.2487 135.6801 118.6937 139.2352
232       128.9657 122.1492 135.7823 118.5408 139.3907
233       128.9662 122.0503 135.8821 118.3892 139.5432
234       128.9674 121.9535 135.9813 118.2405 139.6942
235       128.9708 121.8602 136.0813 118.0961 139.8454
236       128.9742 121.7683 136.1801 117.9537 139.9947
237       128.9703 121.6703 136.2703 117.8059 140.1347
238       128.9676 121.5742 136.3611 117.6604 140.2749
239       128.9661 121.4801 136.4520 117.5173 140.4148
240       128.9655 121.3880 136.5429 117.3768 140.5542
241       128.9648 121.2968 136.6327 117.2377 140.6918
242       128.9658 121.2084 136.7232 117.1019 140.8297
243       128.9656 121.1197 136.8114 116.9664 140.9648
244       128.9660 121.0327 136.8993 116.8330 141.0990
245       128.9661 120.9463 136.9860 116.7008 141.2315
246       128.9665 120.8610 137.0720 116.5702 141.3628
247       128.9676 120.7774 137.1578 116.4417 141.4934
248       128.9686 120.6946 137.2427 116.3146 141.6227
249       128.9674 120.6103 137.3245 116.1864 141.7485
250       128.9666 120.5272 137.4060 116.0596 141.8736
251       128.9661 120.4451 137.4871 115.9343 141.9979
252       128.9659 120.3640 137.5678 115.8105 142.1214
253       128.9657 120.2837 137.6477 115.6877 142.2437
254       128.9660 120.2046 137.7275 115.5665 142.3655
255       128.9660 120.1258 137.8061 115.4461 142.4858
256       128.9661 120.0479 137.8842 115.3269 142.6052
257       128.9661 119.9706 137.9616 115.2087 142.7236
258       128.9662 119.8941 138.0384 115.0915 142.8409
259       128.9666 119.8183 138.1148 114.9756 142.9576
260       131.3560 122.1324 140.5797 117.2497 145.4623
261       131.3556 122.0572 140.6541 117.1349 145.5764
262       131.3554 121.9827 140.7281 117.0211 145.6896
263       131.3552 121.9089 140.8016 116.9083 145.8022
264       131.3552 121.8357 140.8746 116.7964 145.9139
265       131.3551 121.7631 140.9471 116.6854 146.0248
266       131.3552 121.6912 141.0193 116.5753 146.1351
267       131.3552 121.6196 141.0907 116.4660 146.2444
268       131.3552 121.5487 141.1617 116.3575 146.3530
269       131.3552 121.4783 141.2322 116.2497 146.4608
270       131.3553 121.4083 141.3022 116.1427 146.5678
271       131.3554 121.3390 141.3718 116.0366 146.6742
272       131.3555 121.2701 141.4409 115.9312 146.7798
273       131.3554 121.2014 141.5093 115.8263 146.8845
274       131.3553 121.1333 141.5773 115.7221 146.9885
275       131.3552 121.0656 141.6449 115.6186 147.0919
276       131.3552 120.9984 141.7121 115.5158 147.1946
277       131.3552 120.9316 141.7788 115.4137 147.2967
278       131.3552 120.8653 141.8452 115.3122 147.3982
279       131.3552 120.7993 141.9111 115.2114 147.4990
280       131.3552 120.7338 141.9766 115.1112 147.5992
281       131.3552 120.6687 142.0417 115.0116 147.6988
282       131.3552 120.6040 142.1065 114.9127 147.7978
283       131.3553 120.5397 142.1708 114.8143 147.8962
284       131.3553 120.4758 142.2348 114.7166 147.9941
285       131.3553 120.4122 142.2983 114.6193 148.0913
286       131.3552 120.3490 142.3615 114.5226 148.1879
287       131.3552 120.2861 142.4244 114.4264 148.2840
288       131.3552 120.2236 142.4869 114.3309 148.3796
289       131.3552 120.1614 142.5490 114.2358 148.4747
290       131.3552 120.0996 142.6108 114.1413 148.5692
291       131.3552 120.0382 142.6723 114.0473 148.6632
292       131.3552 119.9770 142.7334 113.9538 148.7567
293       131.3552 119.9162 142.7943 113.8608 148.8497
294       131.3552 119.8557 142.8548 113.7683 148.9422
295       131.3552 119.7956 142.9149 113.6762 149.0343
296       131.3553 119.7357 142.9748 113.5847 149.1258
297       131.3552 119.6761 143.0344 113.4936 149.2169
298       131.3552 119.6169 143.0936 113.4030 149.3075
299       131.3552 119.5579 143.1526 113.3128 149.3977
300       131.3552 119.4993 143.2112 113.2231 149.4874
301       131.3552 119.4409 143.2696 113.1338 149.5767
302       131.3552 119.3828 143.3277 113.0450 149.6655
303       131.3552 119.3250 143.3855 112.9565 149.7539
304       131.3552 119.2674 143.4430 112.8686 149.8419
305       131.3552 119.2102 143.5003 112.7810 149.9295
306       131.3552 119.1532 143.5573 112.6938 150.0167
307       131.3552 119.0965 143.6140 112.6071 150.1034
308       131.3552 119.0400 143.6705 112.5207 150.1898
309       131.3552 118.9838 143.7267 112.4347 150.2757
310       131.3552 118.9278 143.7826 112.3492 150.3613
311       131.3552 118.8721 143.8383 112.2640 150.4465
312       131.3552 118.8167 143.8938 112.1792 150.5313
313       131.3552 118.7615 143.9490 112.0947 150.6158
314       131.3552 118.7065 144.0040 112.0106 150.6998
315       131.3552 118.6518 144.0587 111.9269 150.7835
316       131.3552 118.5973 144.1132 111.8436 150.8669
317       131.3552 118.5430 144.1675 111.7606 150.9499
318       131.3552 118.4890 144.2215 111.6780 151.0325
319       131.3552 118.4351 144.2753 111.5957 151.1148
320       131.3552 118.3816 144.3289 111.5137 151.1968
321       131.3552 118.3282 144.3823 111.4321 151.2784
322       131.3552 118.2750 144.4354 111.3508 151.3597
323       131.3552 118.2221 144.4884 111.2698 151.4406
324       131.3552 118.1694 144.5411 111.1892 151.5213
325       131.3552 118.1169 144.5936 111.1089 151.6016
326       131.3552 118.0646 144.6459 111.0289 151.6816
327       131.3552 118.0125 144.6980 110.9492 151.7613
328       131.3552 117.9606 144.7499 110.8698 151.8406
329       131.3552 117.9089 144.8016 110.7908 151.9197
330       131.3552 117.8574 144.8531 110.7120 151.9985
331       131.3552 117.8061 144.9044 110.6335 152.0769
332       131.3552 117.7549 144.9555 110.5554 152.1551
333       131.3552 117.7040 145.0064 110.4775 152.2330
334       131.3552 117.6533 145.0572 110.3999 152.3105
335       131.3552 117.6027 145.1077 110.3226 152.3878
336       131.3552 117.5524 145.1581 110.2456 152.4649
337       131.3552 117.5022 145.2083 110.1689 152.5416
338       131.3552 117.4522 145.2582 110.0924 152.6181
339       131.3552 117.4024 145.3081 110.0162 152.6942
340       131.3552 117.3528 145.3577 109.9403 152.7702
341       131.3552 117.3033 145.4072 109.8647 152.8458
342       131.3552 117.2540 145.4565 109.7893 152.9212
343       131.3552 117.2049 145.5056 109.7142 152.9963
344       131.3552 117.1560 145.5545 109.6393 153.0712
345       131.3552 117.1072 145.6033 109.5647 153.1458
346       131.3552 117.0586 145.6519 109.4904 153.2201
347       131.3552 117.0101 145.7004 109.4163 153.2942
348       131.3552 116.9618 145.7486 109.3424 153.3680
349       131.3552 116.9137 145.7968 109.2688 153.4416
350       131.3552 116.8657 145.8447 109.1955 153.5150
351       131.3552 116.8179 145.8925 109.1224 153.5881
352       131.3552 116.7703 145.9402 109.0495 153.6610
353       131.3552 116.7228 145.9877 108.9769 153.7336
354       131.3552 116.6755 146.0350 108.9045 153.8060
355       131.3552 116.6283 146.0822 108.8323 153.8782
356       131.3552 116.5812 146.1292 108.7604 153.9501
357       131.3552 116.5343 146.1761 108.6886 154.0218
358       130.3062 115.4385 145.1738 107.5681 153.0442
359       130.3062 115.3920 145.2204 107.4968 153.1155
360       130.3062 115.3455 145.2668 107.4258 153.1865
361       130.3062 115.2992 145.3131 107.3550 153.2574
362       130.3062 115.2530 145.3593 107.2844 153.3280
363       130.3062 115.2070 145.4053 107.2140 153.3983
364       130.3062 115.1611 145.4512 107.1438 153.4685
365       130.3062 115.1154 145.4969 107.0739 153.5385
366       130.3062 115.0698 145.5426 107.0041 153.6082
367       130.3062 115.0243 145.5880 106.9346 153.6777
368       130.3062 114.9790 145.6334 106.8653 153.7471
369       130.3062 114.9338 145.6786 106.7961 153.8162
370       130.3062 114.8887 145.7236 106.7272 153.8851
371       130.3062 114.8438 145.7686 106.6585 153.9539
372       130.3062 114.7990 145.8134 106.5900 154.0224
373       130.3062 114.7543 145.8580 106.5216 154.0907
374       130.3062 114.7098 145.9026 106.4535 154.1588
375       130.3062 114.6653 145.9470 106.3856 154.2268
376       130.3062 114.6210 145.9913 106.3178 154.2945
377       130.3062 114.5769 146.0355 106.2503 154.3621
378       130.3062 114.5328 146.0795 106.1829 154.4294

La mayoría de los valores pronosticados (Point Forecast) se mantienen relativamente estables alrededor de 126 durante los primeros periodos (190–205).

A partir del periodo 206–259, hay un salto hacia 126–128, lo que indica que el modelo espera un aumento repentino en la serie temporal. Y asi sucesivamente con los demas

La serie pronosticada se mantiene estable al inicio, con una tendencia creciente hacia el final, y los intervalos muestran que la confianza del pronóstico disminuye cuanto más lejos estamos del periodo actual.

summary(predicciones)

Forecast method: Regression with ARIMA(1,1,0)(2,0,0)[12] errors

Model Information:
Series: ipc_data$ipc_general 
Regression with ARIMA(1,1,0)(2,0,0)[12] errors 

Coefficients:
         ar1    sar1    sar2   xreg1   xreg2    xreg3
      0.5210  0.2307  0.0253  2.5063  2.3891  -1.0491
s.e.  0.0637  0.0799  0.0820  0.2942  0.2876   0.2837

sigma^2 = 0.1073:  log likelihood = -54.37
AIC=122.73   AICc=123.35   BIC=145.39

Error measures:
                     ME      RMSE       MAE        MPE      MAPE      MASE
Training set 0.04958185 0.3214601 0.2603451 0.04319565 0.2295182 0.7598956
                    ACF1
Training set -0.03066765

Forecasts:
    Point Forecast    Lo 80    Hi 80    Lo 95    Hi 95
190       126.6526 126.2328 127.0724 126.0105 127.2947
191       126.4766 125.7125 127.2408 125.3079 127.6454
192       126.4036 125.3312 127.4761 124.7634 128.0438
193       126.3274 124.9823 127.6725 124.2703 128.3846
194       126.4277 124.8404 128.0150 124.0001 128.8553
195       126.4080 124.6032 128.2127 123.6478 129.1681
196       126.4476 124.4453 128.4500 123.3853 129.5100
197       126.4642 124.2804 128.6481 123.1243 129.8042
198       126.5021 124.1499 128.8543 122.9047 130.0995
199       126.6080 124.0983 129.1178 122.7697 130.4464
200       126.7166 124.0584 129.3747 122.6513 130.7819
201       126.5928 123.7940 129.3916 122.3124 130.8732
202       126.5073 123.5441 129.4704 121.9756 131.0390
203       126.4570 123.3221 129.5920 121.6625 131.2515
204       126.4374 123.1313 129.7435 121.3811 131.4936
205       126.4142 122.9412 129.8872 121.1027 131.7257
206       128.9550 125.3207 132.5893 123.3968 134.5132
207       128.9484 125.1586 132.7382 123.1524 134.7445
208       128.9621 125.0224 132.9019 122.9368 134.9874
209       128.9670 124.8826 133.0514 122.7204 135.2136
210       128.9793 124.7550 133.2035 122.5188 135.4397
211       129.0143 124.6546 133.3741 122.3467 135.6820
212       129.0503 124.5591 133.5414 122.1817 135.9188
213       129.0095 124.3908 133.6283 121.9457 136.0734
214       128.9819 124.2313 133.7326 121.7164 136.2474
215       128.9659 124.0830 133.8488 121.4981 136.4336
216       128.9595 123.9458 133.9732 121.2918 136.6273
217       128.9522 123.8101 134.0944 121.0880 136.8165
218       128.9627 123.6947 134.2308 120.9060 137.0195
219       128.9607 123.5695 134.3520 120.7155 137.2059
220       128.9649 123.4530 134.4767 120.5352 137.3945
221       128.9664 123.3365 134.5964 120.3562 137.5767
222       128.9702 123.2246 134.7159 120.1830 137.7574
223       128.9810 123.1219 134.8401 120.0203 137.9417
224       128.9920 123.0217 134.9624 119.8612 138.1229
225       128.9795 122.8999 135.0591 119.6816 138.2774
226       128.9710 122.7822 135.1598 119.5060 138.4359
227       128.9660 122.6689 135.2631 119.3355 138.5965
228       128.9640 122.5600 135.3680 119.1699 138.7581
229       128.9618 122.4523 135.4712 119.0064 138.9171
230       128.9651 122.3517 135.5784 118.8508 139.0793
231       128.9644 122.2487 135.6801 118.6937 139.2352
232       128.9657 122.1492 135.7823 118.5408 139.3907
233       128.9662 122.0503 135.8821 118.3892 139.5432
234       128.9674 121.9535 135.9813 118.2405 139.6942
235       128.9708 121.8602 136.0813 118.0961 139.8454
236       128.9742 121.7683 136.1801 117.9537 139.9947
237       128.9703 121.6703 136.2703 117.8059 140.1347
238       128.9676 121.5742 136.3611 117.6604 140.2749
239       128.9661 121.4801 136.4520 117.5173 140.4148
240       128.9655 121.3880 136.5429 117.3768 140.5542
241       128.9648 121.2968 136.6327 117.2377 140.6918
242       128.9658 121.2084 136.7232 117.1019 140.8297
243       128.9656 121.1197 136.8114 116.9664 140.9648
244       128.9660 121.0327 136.8993 116.8330 141.0990
245       128.9661 120.9463 136.9860 116.7008 141.2315
246       128.9665 120.8610 137.0720 116.5702 141.3628
247       128.9676 120.7774 137.1578 116.4417 141.4934
248       128.9686 120.6946 137.2427 116.3146 141.6227
249       128.9674 120.6103 137.3245 116.1864 141.7485
250       128.9666 120.5272 137.4060 116.0596 141.8736
251       128.9661 120.4451 137.4871 115.9343 141.9979
252       128.9659 120.3640 137.5678 115.8105 142.1214
253       128.9657 120.2837 137.6477 115.6877 142.2437
254       128.9660 120.2046 137.7275 115.5665 142.3655
255       128.9660 120.1258 137.8061 115.4461 142.4858
256       128.9661 120.0479 137.8842 115.3269 142.6052
257       128.9661 119.9706 137.9616 115.2087 142.7236
258       128.9662 119.8941 138.0384 115.0915 142.8409
259       128.9666 119.8183 138.1148 114.9756 142.9576
260       131.3560 122.1324 140.5797 117.2497 145.4623
261       131.3556 122.0572 140.6541 117.1349 145.5764
262       131.3554 121.9827 140.7281 117.0211 145.6896
263       131.3552 121.9089 140.8016 116.9083 145.8022
264       131.3552 121.8357 140.8746 116.7964 145.9139
265       131.3551 121.7631 140.9471 116.6854 146.0248
266       131.3552 121.6912 141.0193 116.5753 146.1351
267       131.3552 121.6196 141.0907 116.4660 146.2444
268       131.3552 121.5487 141.1617 116.3575 146.3530
269       131.3552 121.4783 141.2322 116.2497 146.4608
270       131.3553 121.4083 141.3022 116.1427 146.5678
271       131.3554 121.3390 141.3718 116.0366 146.6742
272       131.3555 121.2701 141.4409 115.9312 146.7798
273       131.3554 121.2014 141.5093 115.8263 146.8845
274       131.3553 121.1333 141.5773 115.7221 146.9885
275       131.3552 121.0656 141.6449 115.6186 147.0919
276       131.3552 120.9984 141.7121 115.5158 147.1946
277       131.3552 120.9316 141.7788 115.4137 147.2967
278       131.3552 120.8653 141.8452 115.3122 147.3982
279       131.3552 120.7993 141.9111 115.2114 147.4990
280       131.3552 120.7338 141.9766 115.1112 147.5992
281       131.3552 120.6687 142.0417 115.0116 147.6988
282       131.3552 120.6040 142.1065 114.9127 147.7978
283       131.3553 120.5397 142.1708 114.8143 147.8962
284       131.3553 120.4758 142.2348 114.7166 147.9941
285       131.3553 120.4122 142.2983 114.6193 148.0913
286       131.3552 120.3490 142.3615 114.5226 148.1879
287       131.3552 120.2861 142.4244 114.4264 148.2840
288       131.3552 120.2236 142.4869 114.3309 148.3796
289       131.3552 120.1614 142.5490 114.2358 148.4747
290       131.3552 120.0996 142.6108 114.1413 148.5692
291       131.3552 120.0382 142.6723 114.0473 148.6632
292       131.3552 119.9770 142.7334 113.9538 148.7567
293       131.3552 119.9162 142.7943 113.8608 148.8497
294       131.3552 119.8557 142.8548 113.7683 148.9422
295       131.3552 119.7956 142.9149 113.6762 149.0343
296       131.3553 119.7357 142.9748 113.5847 149.1258
297       131.3552 119.6761 143.0344 113.4936 149.2169
298       131.3552 119.6169 143.0936 113.4030 149.3075
299       131.3552 119.5579 143.1526 113.3128 149.3977
300       131.3552 119.4993 143.2112 113.2231 149.4874
301       131.3552 119.4409 143.2696 113.1338 149.5767
302       131.3552 119.3828 143.3277 113.0450 149.6655
303       131.3552 119.3250 143.3855 112.9565 149.7539
304       131.3552 119.2674 143.4430 112.8686 149.8419
305       131.3552 119.2102 143.5003 112.7810 149.9295
306       131.3552 119.1532 143.5573 112.6938 150.0167
307       131.3552 119.0965 143.6140 112.6071 150.1034
308       131.3552 119.0400 143.6705 112.5207 150.1898
309       131.3552 118.9838 143.7267 112.4347 150.2757
310       131.3552 118.9278 143.7826 112.3492 150.3613
311       131.3552 118.8721 143.8383 112.2640 150.4465
312       131.3552 118.8167 143.8938 112.1792 150.5313
313       131.3552 118.7615 143.9490 112.0947 150.6158
314       131.3552 118.7065 144.0040 112.0106 150.6998
315       131.3552 118.6518 144.0587 111.9269 150.7835
316       131.3552 118.5973 144.1132 111.8436 150.8669
317       131.3552 118.5430 144.1675 111.7606 150.9499
318       131.3552 118.4890 144.2215 111.6780 151.0325
319       131.3552 118.4351 144.2753 111.5957 151.1148
320       131.3552 118.3816 144.3289 111.5137 151.1968
321       131.3552 118.3282 144.3823 111.4321 151.2784
322       131.3552 118.2750 144.4354 111.3508 151.3597
323       131.3552 118.2221 144.4884 111.2698 151.4406
324       131.3552 118.1694 144.5411 111.1892 151.5213
325       131.3552 118.1169 144.5936 111.1089 151.6016
326       131.3552 118.0646 144.6459 111.0289 151.6816
327       131.3552 118.0125 144.6980 110.9492 151.7613
328       131.3552 117.9606 144.7499 110.8698 151.8406
329       131.3552 117.9089 144.8016 110.7908 151.9197
330       131.3552 117.8574 144.8531 110.7120 151.9985
331       131.3552 117.8061 144.9044 110.6335 152.0769
332       131.3552 117.7549 144.9555 110.5554 152.1551
333       131.3552 117.7040 145.0064 110.4775 152.2330
334       131.3552 117.6533 145.0572 110.3999 152.3105
335       131.3552 117.6027 145.1077 110.3226 152.3878
336       131.3552 117.5524 145.1581 110.2456 152.4649
337       131.3552 117.5022 145.2083 110.1689 152.5416
338       131.3552 117.4522 145.2582 110.0924 152.6181
339       131.3552 117.4024 145.3081 110.0162 152.6942
340       131.3552 117.3528 145.3577 109.9403 152.7702
341       131.3552 117.3033 145.4072 109.8647 152.8458
342       131.3552 117.2540 145.4565 109.7893 152.9212
343       131.3552 117.2049 145.5056 109.7142 152.9963
344       131.3552 117.1560 145.5545 109.6393 153.0712
345       131.3552 117.1072 145.6033 109.5647 153.1458
346       131.3552 117.0586 145.6519 109.4904 153.2201
347       131.3552 117.0101 145.7004 109.4163 153.2942
348       131.3552 116.9618 145.7486 109.3424 153.3680
349       131.3552 116.9137 145.7968 109.2688 153.4416
350       131.3552 116.8657 145.8447 109.1955 153.5150
351       131.3552 116.8179 145.8925 109.1224 153.5881
352       131.3552 116.7703 145.9402 109.0495 153.6610
353       131.3552 116.7228 145.9877 108.9769 153.7336
354       131.3552 116.6755 146.0350 108.9045 153.8060
355       131.3552 116.6283 146.0822 108.8323 153.8782
356       131.3552 116.5812 146.1292 108.7604 153.9501
357       131.3552 116.5343 146.1761 108.6886 154.0218
358       130.3062 115.4385 145.1738 107.5681 153.0442
359       130.3062 115.3920 145.2204 107.4968 153.1155
360       130.3062 115.3455 145.2668 107.4258 153.1865
361       130.3062 115.2992 145.3131 107.3550 153.2574
362       130.3062 115.2530 145.3593 107.2844 153.3280
363       130.3062 115.2070 145.4053 107.2140 153.3983
364       130.3062 115.1611 145.4512 107.1438 153.4685
365       130.3062 115.1154 145.4969 107.0739 153.5385
366       130.3062 115.0698 145.5426 107.0041 153.6082
367       130.3062 115.0243 145.5880 106.9346 153.6777
368       130.3062 114.9790 145.6334 106.8653 153.7471
369       130.3062 114.9338 145.6786 106.7961 153.8162
370       130.3062 114.8887 145.7236 106.7272 153.8851
371       130.3062 114.8438 145.7686 106.6585 153.9539
372       130.3062 114.7990 145.8134 106.5900 154.0224
373       130.3062 114.7543 145.8580 106.5216 154.0907
374       130.3062 114.7098 145.9026 106.4535 154.1588
375       130.3062 114.6653 145.9470 106.3856 154.2268
376       130.3062 114.6210 145.9913 106.3178 154.2945
377       130.3062 114.5769 146.0355 106.2503 154.3621
378       130.3062 114.5328 146.0795 106.1829 154.4294

Aqui observamis lo que es como un resumen de lo que son las predicciones que nos dieron. Utilizamos lo que es el ARIMA (1,1,0) (2,0,0) el cual ocupa el modelo 6 con un AIC = 122.73 y un BIC=145.39

plot(predicciones)

El modelo ARIMA predice que la serie se mantendrá estable en el futuro..

autoplot(predicciones)

El ARIMA está pronosticando estabilidad del IPC

library(TSstudio)
Warning: package 'TSstudio' was built under R version 4.3.3
TSstudio::ts_plot(serie1)