A continuación se realizará un análisis geoestadístico a partir de los datos de una finca de aguacate ubicada en el Cauca. El objetivo es realizar una análisis exploratorio y aplicar las diferentes fases para llegar una predicción final sobre el desempeño del cultivo teniendo en cuenta la temperatura.
require(geoR)
## Loading required package: geoR
## --------------------------------------------------------------
## Analysis of Geostatistical Data
## For an Introduction to geoR go to http://www.leg.ufpr.br/geoR
## geoR version 1.9-4 (built on 2024-02-14) is now loaded
## --------------------------------------------------------------
Se importan los datos
library(readxl)
datos <- read_excel("C:/Users/diaramos/Downloads/Datos_Completos_Aguacate.xlsx")
head(datos)
## # A tibble: 6 × 21
## id_arbol Latitude Longitude FORMATTED_DATE_TIME Psychro_Wet_Bulb_Temp…¹
## <dbl> <dbl> <dbl> <chr> <dbl>
## 1 1 2.39 -76.7 01/10/2020 10:11:12 a, m, 22
## 2 2 2.39 -76.7 01/10/2020 10:11:12 a, m, 21.4
## 3 3 2.39 -76.7 01/10/2020 10:11:12 a, m, 21.8
## 4 4 2.39 -76.7 01/10/2020 10:11:12 a, m, 22.8
## 5 5 2.39 -76.7 01/10/2020 10:11:12 a, m, 22.6
## 6 6 2.39 -76.7 01/10/2020 10:11:12 a, m, 21.5
## # ℹ abbreviated name: ¹Psychro_Wet_Bulb_Temperature
## # ℹ 16 more variables: Station_Pressure <dbl>, Relative_Humidity <dbl>,
## # Crosswind <dbl>, Temperature <dbl>, Barometric_Pressure <dbl>,
## # Headwind <dbl>, Direction_True <dbl>, Direction_Mag <dbl>,
## # Wind_Speed <dbl>, Heat_Stress_Index <dbl>, Altitude <dbl>, Dew_Point <dbl>,
## # Density_Altitude <dbl>, Wind_Chill <dbl>,
## # Estado_Fenologico_Predominante <dbl>, Frutos_Afectados <dbl>
plot(datos[,2:3])
Conversión de datos en una variable regionalizada
geodatos=as.geodata(datos,coords.col = 2:3, data.col = 9)
plot(geodatos)
Semivariograma Experimental
summary(dist(geodatos$coords))
## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 1.712e-05 4.051e-04 6.408e-04 6.827e-04 9.178e-04 1.959e-03
variograma=variog(geodatos,option = "bin",uvec=seq(0,0.0009178,9.178e-05))
## variog: computing omnidirectional variogram
plot(variograma)
variograma_mc=variog.mc.env(geodatos,obj=variograma)
## variog.env: generating 99 simulations by permutating data values
## variog.env: computing the empirical variogram for the 99 simulations
## variog.env: computing the envelops
Ajuste al modelo teórico
ini.vals = expand.grid(seq(2.5,5,l=10), seq(2e-04,4e-04,l=10))
model_mco_exp=variofit(variograma, ini=ini.vals,cov.model = "exponential")
## variofit: covariance model used is exponential
## variofit: weights used: npairs
## variofit: minimisation function used: optim
## variofit: searching for best initial value ... selected values:
## sigmasq phi tausq kappa
## initial.value "3.33" "0" "0" "0.5"
## status "est" "est" "est" "fix"
## loss value: 7099.8801844616
model_mco_gaus=variofit(variograma, ini=ini.vals,cov.model = "gaussian")
## variofit: covariance model used is gaussian
## variofit: weights used: npairs
## variofit: minimisation function used: optim
## variofit: searching for best initial value ... selected values:
## sigmasq phi tausq kappa
## initial.value "3.33" "0" "0" "0.5"
## status "est" "est" "est" "fix"
## loss value: 17334.9437752326
model_mco_spe=variofit(variograma, ini=ini.vals,cov.model = "sph")
## variofit: covariance model used is spherical
## variofit: weights used: npairs
## variofit: minimisation function used: optim
## variofit: searching for best initial value ... selected values:
## sigmasq phi tausq kappa
## initial.value "3.06" "0" "0" "0.5"
## status "est" "est" "est" "fix"
## loss value: 6728.0618160963