examen de mnodelos

Impórtacion de datos

datos2=scan("http://robjhyndman.com/tsdldata/data/nybirths.dat")
datos3=scan("http://robjhyndman.com/tsdldata/data/fancy.dat")
head(datos2)

## [1] 26.663 23.598 26.931 24.740 25.806 24.364

datos2

##   [1] 26.663 23.598 26.931 24.740 25.806 24.364 24.477 23.901 23.175 23.227
##  [11] 21.672 21.870 21.439 21.089 23.709 21.669 21.752 20.761 23.479 23.824
##  [21] 23.105 23.110 21.759 22.073 21.937 20.035 23.590 21.672 22.222 22.123
##  [31] 23.950 23.504 22.238 23.142 21.059 21.573 21.548 20.000 22.424 20.615
##  [41] 21.761 22.874 24.104 23.748 23.262 22.907 21.519 22.025 22.604 20.894
##  [51] 24.677 23.673 25.320 23.583 24.671 24.454 24.122 24.252 22.084 22.991
##  [61] 23.287 23.049 25.076 24.037 24.430 24.667 26.451 25.618 25.014 25.110
##  [71] 22.964 23.981 23.798 22.270 24.775 22.646 23.988 24.737 26.276 25.816
##  [81] 25.210 25.199 23.162 24.707 24.364 22.644 25.565 24.062 25.431 24.635
##  [91] 27.009 26.606 26.268 26.462 25.246 25.180 24.657 23.304 26.982 26.199
## [101] 27.210 26.122 26.706 26.878 26.152 26.379 24.712 25.688 24.990 24.239
## [111] 26.721 23.475 24.767 26.219 28.361 28.599 27.914 27.784 25.693 26.881
## [121] 26.217 24.218 27.914 26.975 28.527 27.139 28.982 28.169 28.056 29.136
## [131] 26.291 26.987 26.589 24.848 27.543 26.896 28.878 27.390 28.065 28.141
## [141] 29.048 28.484 26.634 27.735 27.132 24.924 28.963 26.589 27.931 28.009
## [151] 29.229 28.759 28.405 27.945 25.912 26.619 26.076 25.286 27.660 25.951
## [161] 26.398 25.565 28.865 30.000 29.261 29.012 26.992 27.897

length(datos2)

## [1] 168

conversion de datos a ts

st2=ts(datos2,start = c(1946,1),frequency = 12)
plot(st2)

summary(st2)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   20.00   23.28   24.96   25.06   26.88   30.00

Iterpretacion

• desde 1948 empieza a tener tendencia, tiene factor ciclo y es estacional, sus puntos de manera global son : max es de 30.00 y minimo es de 20:00.

##exportar los datos

library(writexl)

## Warning: package 'writexl' was built under R version 4.5.1

d2=as.data.frame(datos2)
d3=as.data.frame(datos3)
write_xlsx(d2,"datos2_examen1.xlsx")
write_xlsx(d3,"datos3_examen1.xlsx")

diferencias

st1d=diff(st2,1)
plot(st1d)

st1d12=diff(st1d,12)
plot(st1d12)