AUTOCORRELACION ESPACIAL VARIABLE DE SALINIDAD

library(geoR)
## --------------------------------------------------------------
##  Analysis of Geostatistical Data
##  For an Introduction to geoR go to http://www.leg.ufpr.br/geoR
##  geoR version 1.8-1 (built on 2020-02-08) is now loaded
## --------------------------------------------------------------
library(readxl)

#----- 1. Cargar los datos desde tabla de excel 
datos=read_excel("D:/ESPECIALIZACION/SEMESTRE_1/1. Tratamiento de datos/Clase_9_Geoestadistica3/base_cienaga.xls")
datos
## # A tibble: 114 x 6
##       Este    Norte  prof  temp  sali  oxig
##      <dbl>    <dbl> <dbl> <dbl> <dbl> <dbl>
##  1 976952  1706444   1.75  26.4  29.0  6.34
##  2 970883. 1704880.  1.4   30.3  13.0  9.42
##  3 972704. 1704827.  1.1   30.4  19.2  7.88
##  4 974718  1704874   1.5   28.3  35.0  5.67
##  5 976538  1704874   0.5   27    34.0  5.49
##  6 955344. 1703160.  1.62  26    18.0  5.07
##  7 957298. 1703153.  1.55  26.5  18.8  4.53
##  8 959187. 1703146.  1.41  26.9  15.5  5.51
##  9 961189. 1703130.  0.25  27.5  18.9  6.69
## 10 963090. 1703199.  1.54  29    17.2  8.32
## # ... with 104 more rows
plot(datos[,1:2]) # visualizar coordenadas col 1 y 2 (distribucion espacial) 

#----- 2. Convertir datos a geodatos, 
geodatos5=as.geodata(datos,coords.col=1:2,data.col=5)
class(geodatos5)
## [1] "geodata"
geodatos5
## $coords
##            Este   Norte
##   [1,] 976952.0 1706444
##   [2,] 970882.6 1704880
##   [3,] 972704.2 1704827
##   [4,] 974718.0 1704874
##   [5,] 976538.0 1704874
##   [6,] 955343.6 1703160
##   [7,] 957297.9 1703153
##   [8,] 959186.6 1703146
##   [9,] 961189.0 1703130
##  [10,] 963090.1 1703199
##  [11,] 964999.8 1703147
##  [12,] 966967.1 1703160
##  [13,] 968960.1 1703126
##  [14,] 970905.6 1703116
##  [15,] 972615.4 1703029
##  [16,] 974694.0 1703070
##  [17,] 955374.4 1701239
##  [18,] 957299.0 1701231
##  [19,] 959186.0 1701241
##  [20,] 961173.9 1701221
##  [21,] 963061.0 1701237
##  [22,] 964966.7 1701202
##  [23,] 966985.1 1701245
##  [24,] 968980.6 1701206
##  [25,] 970818.9 1701205
##  [26,] 972695.9 1701130
##  [27,] 974699.0 1701133
##  [28,] 953180.2 1699228
##  [29,] 955353.5 1699227
##  [30,] 957270.0 1699205
##  [31,] 959183.6 1699265
##  [32,] 961148.7 1699222
##  [33,] 963078.2 1699297
##  [34,] 964978.1 1699247
##  [35,] 966991.4 1699272
##  [36,] 968883.2 1699239
##  [37,] 970785.0 1699269
##  [38,] 972755.3 1699166
##  [39,] 974763.8 1699209
##  [40,] 953280.1 1697307
##  [41,] 955393.9 1697383
##  [42,] 957294.0 1697305
##  [43,] 959144.4 1697424
##  [44,] 961172.9 1697311
##  [45,] 963052.6 1697384
##  [46,] 964967.9 1697350
##  [47,] 966960.2 1697405
##  [48,] 969019.2 1697291
##  [49,] 970820.8 1697331
##  [50,] 972692.2 1697312
##  [51,] 955389.4 1695340
##  [52,] 957272.0 1695313
##  [53,] 959190.6 1695330
##  [54,] 961161.8 1695337
##  [55,] 963083.2 1695344
##  [56,] 964929.4 1695307
##  [57,] 966984.6 1695356
##  [58,] 968947.0 1695369
##  [59,] 970923.0 1695411
##  [60,] 972704.7 1695314
##  [61,] 957305.4 1693421
##  [62,] 959249.3 1693418
##  [63,] 961193.3 1693539
##  [64,] 963076.3 1693475
##  [65,] 964959.5 1693473
##  [66,] 966964.0 1693471
##  [67,] 968938.3 1693469
##  [68,] 970851.7 1693468
##  [69,] 972492.2 1693958
##  [70,] 957212.0 1691577
##  [71,] 959155.9 1691575
##  [72,] 961160.5 1691450
##  [73,] 963043.7 1691447
##  [74,] 964927.0 1691476
##  [75,] 966840.6 1691505
##  [76,] 968906.0 1691503
##  [77,] 970819.6 1691501
##  [78,] 957179.0 1689549
##  [79,] 959183.8 1689547
##  [80,] 961158.2 1689514
##  [81,] 963041.6 1689573
##  [82,] 964955.4 1689663
##  [83,] 967020.9 1689538
##  [84,] 968934.6 1689567
##  [85,] 970939.5 1689627
##  [86,] 959181.4 1687550
##  [87,] 961186.4 1687609
##  [88,] 963009.1 1687576
##  [89,] 964953.3 1687604
##  [90,] 966988.6 1687602
##  [91,] 968902.4 1687601
##  [92,] 970907.7 1687998
##  [93,] 959209.5 1685706
##  [94,] 961093.1 1685704
##  [95,] 963067.7 1685701
##  [96,] 965012.1 1685730
##  [97,] 966956.3 1685697
##  [98,] 969022.2 1685695
##  [99,] 959207.2 1683801
## [100,] 961121.1 1683706
## [101,] 963035.2 1683704
## [102,] 964858.1 1683764
## [103,] 966954.3 1683639
## [104,] 968443.1 1683699
## [105,] 959174.4 1681804
## [106,] 961149.3 1681801
## [107,] 963063.5 1681861
## [108,] 964916.8 1681797
## [109,] 966922.1 1681826
## [110,] 959172.1 1679929
## [111,] 961147.1 1679927
## [112,] 963061.4 1679925
## [113,] 964945.2 1679923
## [114,] 966950.6 1679921
## 
## $data
##   [1] 28.95 13.03 19.19 34.95 33.99 18.03 18.85 15.47 18.91 17.15 16.41 16.27
##  [13] 14.47 13.88 17.89 16.74 18.78 17.28 18.64 15.20 16.27 16.61 15.94 17.55
##  [25] 16.95 18.50 15.34 18.44 18.85 17.69 16.21 15.54 15.34 15.60 16.01 16.68
##  [37] 16.48 16.21 15.07 18.10 18.16 17.69 16.74 15.40 14.74 14.94 15.07 16.48
##  [49] 16.34 16.01 18.71 17.49 16.68 16.34 15.01 15.81 15.47 17.08 16.74 15.20
##  [61] 19.25 17.96 17.42 16.21 16.74 16.34 16.54 17.28 16.21 19.32 18.23 17.89
##  [73] 17.69 17.62 16.88 17.01 17.08 18.64 18.37 18.50 18.44 18.23 17.15 17.35
##  [85] 16.74 19.19 18.98 18.71 18.16 17.55 16.74 16.95 19.46 19.12 19.05 17.96
##  [97] 17.76 16.88 19.53 19.25 18.91 18.23 16.88 16.74 18.98 18.91 18.71 18.23
## [109] 17.15 18.16 18.50 17.89 17.55 16.61
## 
## attr(,"class")
## [1] "geodata"
plot(geodatos5)

#----- 3. Cálculo del semivariagram muestral
summary(dist(geodatos5$coords))
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    1373    6994   11204   11531   15606   31924
variograma5=variog(geodatos5,option= "bin",uvec=seq(0,20000,1500))
## variog: computing omnidirectional variogram
variograma5
## $u
##  [1]  1500  3000  4500  6000  7500  9000 10500 12000 13500 15000 16500 18000
## [13] 19500
## 
## $v
##  [1]  2.139230  3.323165  3.205625  4.218861  4.155430  5.149708  6.334606
##  [8]  5.290376  6.869555  9.191472 11.714082 11.160215 14.239824
## 
## $n
##  [1] 201 198 494 584 688 510 571 650 601 438 316 396 298
## 
## $sd
##  [1] 14.64185 20.04953 19.55825 22.52982 19.85200 22.48796 26.39760 22.22508
##  [9] 26.67721 31.63044 35.42439 32.96839 36.85020
## 
## $bins.lim
##  [1] 1.000e-12 7.500e+02 2.250e+03 3.750e+03 5.250e+03 6.750e+03 8.250e+03
##  [8] 9.750e+03 1.125e+04 1.275e+04 1.425e+04 1.575e+04 1.725e+04 1.875e+04
## [15] 2.025e+04
## 
## $ind.bin
##  [1] FALSE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE
## [13]  TRUE  TRUE
## 
## $var.mark
## [1] 8.13333
## 
## $beta.ols
## [1] 17.62623
## 
## $output.type
## [1] "bin"
## 
## $max.dist
## [1] 20250
## 
## $estimator.type
## [1] "classical"
## 
## $n.data
## [1] 114
## 
## $lambda
## [1] 1
## 
## $trend
## [1] "cte"
## 
## $pairs.min
## [1] 2
## 
## $nugget.tolerance
## [1] 1e-12
## 
## $direction
## [1] "omnidirectional"
## 
## $tolerance
## [1] "none"
## 
## $uvec
##  [1]     0  1500  3000  4500  6000  7500  9000 10500 12000 13500 15000 16500
## [13] 18000 19500
## 
## $call
## variog(geodata = geodatos5, uvec = seq(0, 20000, 1500), option = "bin")
## 
## attr(,"class")
## [1] "variogram"
plot(variograma5, pch=16)

#----- 4. Permuto datos originales para hacer el calculo del semivariograma
geodatos5.env=variog.mc.env(geodatos5,obj=variograma5) ## metodo montecarlo (variog.mc) calcula el semivariagrama sin autocorrelacion 
## variog.env: generating 99 simulations by permutating data values
## variog.env: computing the empirical variogram for the 99 simulations
## variog.env: computing the envelops
plot(variograma5,pch=16,main=names(datos)[5],envelope =geodatos5.env)


#----- 5. Encuentro la curva que mas se ajuste al semivariograma usuando los modelo gaus, exp o spe (meseta y rango)

ini.vals = expand.grid(seq(2,8,l=10), seq(10000,15000,l=10)) ## rango para encontrar la meseta (valores maximo donde esta la meseta (entre 5,7)

model_mco_exp=variofit(variograma5, ini=ini.vals, cov.model="exponential",wei="npair", min="optim")
## 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 "8"     "10000" "0"   "0.5"
## status        "est"   "est"   "est" "fix"
## loss value: 38967.7442784068
model_mco_gaus=variofit(variograma5, ini=ini.vals, cov.model="gaussian", wei="npair", min="optim",nugget = 0)
## 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 "8"     "10000" "0"   "0.5"
## status        "est"   "est"   "est" "fix"
## loss value: 31695.8923874857
model_mco_spe=variofit(variograma5, ini=ini.vals, cov.model="spheric",fix.nug=TRUE, wei="npair", min="optim")
## 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 "8"     "15000" "0"   "0.5"
## status        "est"   "est"   "fix" "fix"
## loss value: 27179.3901649479
lines(model_mco_exp,col="blue")
lines(model_mco_gaus,col="red")
lines(model_mco_spe,col="purple")

## Suma mínima ponderada de cuadrados:
#--gaussino: 427331.7
#--esferico:7511.132
#--exponential:1945.665 *



#----- 6. Prediccion espacial con el metodo de Kriging
plot(geodatos5$coords)

loc0=cbind( 966988.6, 1687602)
geodatos_ko=krige.conv(geodatos5, loc=loc0,
                       krige= krige.control(nugget=0,trend.d="cte", 
                       trend.l="cte",cov.pars=c(sigmasq=9.04, phi=13858))) # sigmasq(9.04), phi(13858) del exponencial. 
## krige.conv: model with constant mean
## krige.conv: Kriging performed using global neighbourhood
#----- 7. Generacion de la grilla
geodatos_grid=expand.grid(Este=seq(952023,979916,l=100), Norte=seq(1677586,1708649,l=100))
plot(geodatos_grid)
points(geodatos5$coord,col="red",pch=16)

geodatos_ko=krige.conv(geodatos5, loc=geodatos_grid,
                       krige= krige.control(nugget=0,trend.d="cte", 
                       trend.l="cte",cov.pars=c(sigmasq=10.0246, phi=8804.8018)))
## krige.conv: model with constant mean
## krige.conv: Kriging performed using global neighbourhood
image(geodatos_ko, main="kriging Predict", xlab="East", ylab="North")

image(geodatos_ko, main="kriging StDv Predicted",val=sqrt(geodatos_ko$krige.var), xlab="East", ylab="North")