1 Biplot Setup

2 Set up

2.1 1) Load packages

# ---------------------------------------
# Visualize PCA (Biplot) using ggbiplot()
# ---------------------------------------
# clear data and values in golbal environment and close windows or plots
# shell("cls") = Clear console

rm(list = ls(all = TRUE))
graphics.off()
shell("cls")


library(readxl)
library(dplyr)
library(tidyr)
library(tidyverse)
library(janitor)

# ------
# Installing ggbiplot package
# ------

library(devtools)
install_github("vqv/ggbiplot")

#------
# Plotting PCA using ggbiplot()
#------

require(ggbiplot)

2.2 2) Import data

soilhealthpca <- read_excel("7-12-21 part 1 NRCS pca.xlsx") 

#change column names
data <- soilhealthpca %>% 
  clean_names() %>% na.omit()

#names(data)


#colnames(data)[1] <- "sample_pca"
#colnames(data)[2] <- "location"
#colnames(data)[3] <- "treatment"
colnames(data)[4] <- "Clay"
colnames(data)[5] <- "TN"
colnames(data)[6] <- "SOC"
colnames(data)[7] <- "Ca"
colnames(data)[8] <- "Cu"
colnames(data)[9] <- "Mg"
colnames(data)[10] <- "Mn"
colnames(data)[11] <- "Na"
colnames(data)[12] <- "P"
colnames(data)[13] <- "pH"
colnames(data)[14] <- "K"
colnames(data)[15] <- "Zn"
colnames(data)[16] <- "Fe"
colnames(data)[17] <- "CEC"
colnames(data)[18] <- "GWC"
colnames(data)[19] <- "BD"
colnames(data)[20] <- "POXC"
colnames(data)[21] <- "MWD"
colnames(data)[22] <- "Resp"
colnames(data)[23] <- "MB"
colnames(data)[24] <- "GmP"
colnames(data)[25] <- "GmN"
colnames(data)[26] <- "Act"
colnames(data)[27] <- "AMF"
colnames(data)[28] <- "Fun"
colnames(data)[29] <- "FB"
colnames(data)[30] <- "bG"
colnames(data)[31] <- "NAG"
colnames(data)[32] <- "AP"
colnames(data)[33] <- "ALK"
colnames(data)[34] <- "ARY"
colnames(data)[35] <- "PHO"
colnames(data)[36] <- "Pro"


#names(data)

2.3 3) Theme James

library(grid)
library(ggthemes)

pd <- position_dodge(0.1)

theme_James <- function(base_size=14, base_family="TT Times New Roman") {
  (theme_foundation(base_size=base_size, base_family=base_family)+
      theme_bw()+ 
      theme(panel.background = element_rect(colour = NA),
            plot.background = element_rect(colour = NA),
            axis.title = element_text(color="black",size=rel(1.2)),
            axis.text = element_text(color="black", size = 12),
            legend.key = element_rect(colour = NA),
            legend.spacing = unit(0, "cm"),
            legend.text = element_text(size=12),
            legend.title = element_blank(),
            panel.grid = element_blank(),
            plot.title = element_text(color="Black",size = rel(1.5),face = "bold",hjust = 0.5),
            strip.text = element_text(color="Black",size = rel(1),face="bold")
      ))
}

2.4 Overall PCA

#------
# Principal component analysis
#------

require(stats)
pc <- prcomp(x = data[, -(1:3)],       # Give response variable range
             center = TRUE, 
             scale. = TRUE)
print(pc)
## Standard deviations (1, .., p=33):
##  [1] 3.748679e+00 2.223874e+00 1.632756e+00 1.319873e+00 1.139146e+00
##  [6] 1.119728e+00 1.025866e+00 9.654615e-01 8.527696e-01 8.384671e-01
## [11] 7.733103e-01 6.598787e-01 6.386146e-01 5.846609e-01 5.493262e-01
## [16] 5.048305e-01 4.666459e-01 4.469059e-01 3.820419e-01 3.743381e-01
## [21] 3.125559e-01 2.751891e-01 2.702882e-01 2.614230e-01 2.305730e-01
## [26] 2.239487e-01 2.105593e-01 1.854197e-01 1.784957e-01 1.681426e-01
## [31] 1.484083e-01 7.304612e-02 1.664748e-15
## 
## Rotation (n x k) = (33 x 33):
##               PC1          PC2          PC3          PC4          PC5
## Clay  0.108058573 -0.273221846  0.005428374 -0.152537647  0.111331199
## TN   -0.248821995  0.009456019 -0.053087970 -0.000131103  0.074729284
## SOC  -0.242284877 -0.037136420 -0.086643251  0.004775579  0.051864166
## Ca    0.128875985 -0.309297607 -0.213100535  0.086532823  0.164481211
## Cu   -0.045774076 -0.126736258  0.312313193 -0.385915264  0.203970810
## Mg    0.098456907 -0.174669838  0.243924873 -0.140729496 -0.427182379
## Mn   -0.176461809  0.226381630 -0.022810425 -0.270637039  0.065554908
## Na    0.040949079 -0.196764063  0.125886514 -0.436301635 -0.341606947
## P    -0.035069824  0.309004579 -0.285399415 -0.290221266  0.009839775
## pH    0.151042858 -0.269947947 -0.278694564  0.133444552 -0.120654422
## K    -0.052070496  0.285440317 -0.340407773 -0.120847891 -0.144933558
## Zn   -0.219953444  0.005798106 -0.080526424 -0.081818016 -0.012316072
## Fe   -0.152236710  0.121852772  0.366232449 -0.096585189  0.151001425
## CEC   0.142091934 -0.326102862 -0.150247849 -0.017148557 -0.002478381
## GWC  -0.048824265 -0.224981750  0.091257673 -0.217070774  0.174867128
## BD    0.091747245 -0.078593404  0.118898959 -0.052002905  0.527802991
## POXC -0.001819254  0.128394485  0.383970070  0.429112601  0.032645781
## MWD  -0.163403599 -0.154115181  0.037282641 -0.108446320 -0.156694176
## Resp -0.217971627 -0.110838537  0.022246053  0.076230747  0.039567538
## MB   -0.232530890 -0.153581253  0.003550388  0.046623466 -0.073844101
## GmP  -0.225403849 -0.146007314  0.030816366  0.006463688 -0.090291064
## GmN  -0.166826745 -0.068096330  0.085003328  0.150050656 -0.058909148
## Act  -0.167334875 -0.090772262  0.115422253  0.107100082  0.063222440
## AMF  -0.226799257 -0.178239714 -0.016155062  0.012188881  0.086183088
## Fun  -0.177764261 -0.147591107  0.005139120 -0.008975414 -0.227049664
## FB   -0.083743794 -0.093891802 -0.247208566 -0.222570799  0.298985230
## bG   -0.220123868  0.079966086 -0.053468667  0.068763736  0.054663451
## NAG  -0.250216262  0.025446803  0.043458127 -0.037763068 -0.063601734
## AP   -0.244405809  0.032253435 -0.010906364  0.083129113 -0.090727136
## ALK  -0.182531996 -0.142277534 -0.258955109  0.164664044  0.012326900
## ARY  -0.224249508 -0.138581834 -0.008963336  0.088561053 -0.080496184
## PHO  -0.218533879 -0.164206218 -0.076999116  0.062083085  0.141779931
## Pro  -0.223734379  0.129087344 -0.003849623 -0.120613501 -0.028199910
##               PC6          PC7          PC8           PC9          PC10
## Clay -0.102994025  0.158746320 -0.251353789  0.3127470030 -2.237300e-01
## TN   -0.169674168  0.047166168  0.043932584  0.1488709927 -1.137160e-02
## SOC  -0.109017879  0.089692823  0.121806439  0.0529525910  5.133094e-02
## Ca   -0.066384856 -0.076062928  0.146754883  0.1381346217  1.341345e-02
## Cu   -0.108571728 -0.107265870 -0.016445171  0.1892051214  9.368573e-03
## Mg   -0.213652382 -0.194181069  0.142440212 -0.3474870094  7.907649e-03
## Mn   -0.004825207 -0.082704193 -0.046961498  0.1641379567 -1.667136e-01
## Na   -0.096759247 -0.168331173 -0.022229755  0.1666368111  1.793063e-02
## P     0.130430953 -0.007699170  0.233526854  0.0520209033 -5.332517e-02
## pH   -0.070061260 -0.019188064  0.106601439 -0.0112278980  1.431693e-03
## K    -0.022484461 -0.177196207  0.081452384 -0.1660792596 -2.476802e-01
## Zn   -0.318674991 -0.069943355  0.234826737  0.0915494460  4.371361e-05
## Fe    0.094243183  0.215995504  0.009944151  0.0633902966  2.096293e-01
## CEC  -0.124441411 -0.150003720  0.171535990  0.0532932295 -3.370314e-03
## GWC   0.086056651  0.350484526  0.532785188 -0.3557655665  8.811406e-02
## BD   -0.003855021 -0.253182361  0.033310776 -0.2724466846 -5.883331e-01
## POXC -0.283958600 -0.122295130  0.039980558 -0.1016456948 -1.623426e-02
## MWD  -0.115135608  0.257989396 -0.410479562 -0.1008700511 -2.717446e-01
## Resp -0.224974829 -0.217428689  0.106910308  0.1781422115  6.959595e-02
## MB    0.245072607 -0.081910102  0.080179062  0.0354617543 -4.305868e-02
## GmP   0.250323374 -0.081474873 -0.007057506  0.0419793196 -4.185175e-02
## GmN   0.307691647  0.041996219  0.243050697  0.3511204987 -1.212465e-01
## Act   0.262406436 -0.452650248 -0.080978248 -0.0800955518  7.061139e-03
## AMF   0.119805378 -0.147097019  0.036306112 -0.0255107286  1.579435e-01
## Fun   0.386026952 -0.099682133 -0.095147091 -0.1291200589 -1.498114e-01
## FB    0.016421852 -0.164466546 -0.368386260 -0.2993424074  4.990470e-01
## bG   -0.193603253 -0.244749873  0.026342910  0.0527150441  1.255926e-01
## NAG  -0.101652859 -0.001588709 -0.009299107 -0.1222041263 -4.601656e-02
## AP   -0.199799623 -0.015809142 -0.083450612  0.0002706274 -9.844918e-03
## ALK  -0.130348969  0.111698283 -0.095678578 -0.0351743574 -1.557624e-01
## ARY  -0.016943605  0.253580945 -0.075868670 -0.2427426889 -4.001455e-02
## PHO  -0.059701024  0.185794749 -0.028784012 -0.0013458477 -3.039267e-02
## Pro  -0.136925867  0.051692282  0.099468755 -0.1751271408 -1.347884e-01
##              PC11         PC12        PC13         PC14        PC15
## Clay  0.250402134  0.204930601 -0.40527184 -0.276891843  0.35539571
## TN    0.051630710 -0.001922577 -0.01883222  0.026128080 -0.04280210
## SOC   0.167949873 -0.085863635 -0.25611425  0.110306759 -0.08237915
## Ca   -0.098678022 -0.126878412 -0.09498413  0.355166983  0.05559780
## Cu   -0.529112855 -0.331823334  0.16047329 -0.127714258  0.23909956
## Mg    0.112116249 -0.233657281 -0.08600040 -0.173541128  0.03572456
## Mn   -0.137111637  0.077086939  0.02566673 -0.113975328 -0.16517272
## Na    0.277356523  0.396702342  0.36133014  0.153297121 -0.14058025
## P    -0.014390039 -0.073925049  0.06412970  0.213564998  0.02174465
## pH   -0.044631091 -0.048017999  0.02996904 -0.010625622 -0.12184533
## K    -0.088702074 -0.092481154 -0.13972073 -0.252576796  0.06450875
## Zn    0.092860056 -0.100317819 -0.16852343  0.045563389  0.09987104
## Fe    0.205088772 -0.083661540 -0.22129510  0.248246516 -0.01433337
## CEC  -0.037085454 -0.128935594 -0.07345777  0.284357349  0.04702058
## GWC  -0.087192678  0.242252152  0.05270819 -0.174753436  0.05540476
## BD    0.292365907 -0.035821182  0.07864803  0.016781956 -0.23474269
## POXC -0.011216093 -0.059938028  0.13295664  0.018477732  0.13233406
## MWD  -0.133716990 -0.269498103  0.07109959  0.329914746 -0.23287231
## Resp -0.044805707 -0.018738469 -0.16786171 -0.284291466 -0.30242053
## MB   -0.004131372 -0.051165732 -0.05971395 -0.068843940 -0.06005631
## GmP  -0.162384673  0.020860695 -0.09826156 -0.038849600 -0.23240566
## GmN   0.376200663 -0.346251014  0.36896466 -0.127163760  0.08667108
## Act  -0.185430662  0.393492370 -0.12646888  0.222019045  0.18546177
## AMF  -0.013824870 -0.002253462 -0.02160489 -0.002616765 -0.22596068
## Fun   0.050008151 -0.182173200 -0.13520829 -0.014555192  0.34954634
## FB    0.285704930 -0.232723464  0.12564350 -0.135922201  0.05673190
## bG    0.093611941  0.092357304  0.20025788  0.084325609  0.23116177
## NAG   0.034813061  0.042767729 -0.09443522  0.042036171  0.06368226
## AP    0.052062193  0.087422741 -0.02596542 -0.113315941 -0.11602308
## ALK  -0.059690527  0.106052691  0.37043042 -0.103505077  0.26922902
## ARY  -0.022452492  0.046967818 -0.01033459 -0.002129443 -0.05796419
## PHO  -0.150900411  0.148081989  0.20424421 -0.074155813  0.01478460
## Pro   0.084088431  0.037999749 -0.02494080  0.313324022  0.28328099
##              PC16         PC17        PC18         PC19          PC20
## Clay -0.049456636 -0.151374743 -0.06738394  0.083997410  0.1772276403
## TN   -0.062734211  0.249646518  0.20086213 -0.124121490 -0.0452436084
## SOC  -0.131703986  0.166411822  0.12859353 -0.262399655 -0.0006001951
## Ca   -0.034010386  0.026498761 -0.25961016 -0.008932316  0.0336612976
## Cu    0.007780013 -0.090714682  0.13862571 -0.085857378 -0.1726038710
## Mg   -0.136847665 -0.027064325  0.01924354 -0.301137003  0.1190950780
## Mn    0.025917475  0.140294334 -0.61442030  0.023984762 -0.0184799406
## Na    0.094090236  0.147251670 -0.01078146 -0.029901264  0.0109759679
## P     0.161698825  0.039545736  0.12036335  0.037808456  0.2262086159
## pH    0.152341410 -0.163107886  0.01169045  0.087387170 -0.1242770926
## K    -0.308682480 -0.007804507 -0.01991725 -0.081151835  0.2033730503
## Zn    0.136653749  0.258294572  0.22402261  0.201441503 -0.2503760335
## Fe    0.060440149  0.007785063  0.03277298 -0.205363635  0.2613882433
## CEC  -0.075986884  0.035665808 -0.23663518 -0.088472411  0.0761796976
## GWC  -0.111021423  0.057016287 -0.02400137  0.366416603  0.1434707142
## BD    0.126854590 -0.036202279  0.14121052 -0.078173547 -0.0796976138
## POXC  0.143952538  0.222650695 -0.28423409  0.144687159  0.2683760568
## MWD  -0.237206485  0.016059982  0.11095611  0.395387360  0.2463958607
## Resp  0.050355305  0.060293972  0.01213870  0.225591157  0.1524672452
## MB    0.155808243 -0.083258329 -0.02915388  0.006416782  0.0973796055
## GmP   0.157589703 -0.217518770  0.07904430 -0.139114494  0.1580252678
## GmN  -0.401402259 -0.051796649 -0.10835094  0.074740778 -0.1001717072
## Act  -0.458646524  0.191724597  0.12989928  0.064203143 -0.0669929870
## AMF   0.066916987 -0.166871414 -0.10670826 -0.028435306  0.1682773455
## Fun   0.468373067  0.274127529 -0.02898833  0.150922683 -0.0820973953
## FB   -0.062835268  0.115359087 -0.13263487  0.082202972 -0.0024234966
## bG    0.080473778 -0.548788102  0.18836069  0.149810484  0.1480420080
## NAG  -0.027762857 -0.195866380 -0.21413110 -0.096949378  0.0631413478
## AP   -0.008399491 -0.038412008 -0.02881928  0.173186097 -0.3015839049
## ALK   0.078095474  0.196744633  0.13502494 -0.197222158  0.3413413913
## ARY  -0.039869578 -0.111038944 -0.08893062 -0.125598091 -0.3728468712
## PHO   0.043660994  0.087775763 -0.09737923 -0.397848604 -0.0266282327
## Pro   0.028587920 -0.268322204 -0.23368077  0.009110828 -0.1900749551
##               PC21        PC22         PC23         PC24          PC25
## Clay  0.0203687434  0.13637213  0.202528626 -0.047374705 -0.0281629471
## TN   -0.1902733403 -0.09098972 -0.099008147  0.180030582  0.0437824081
## SOC  -0.1228376773  0.06007155 -0.172980255  0.201299302 -0.3198568620
## Ca   -0.0699652959  0.03535872 -0.123209483  0.011273816  0.1071608075
## Cu   -0.1517108335  0.02320060  0.073676198  0.124296436  0.0590209865
## Mg    0.1651687247 -0.09691112 -0.028215394 -0.329784666 -0.0909260744
## Mn    0.2790257381 -0.13680844 -0.255851580 -0.059982055 -0.0863428505
## Na   -0.1159736935  0.14191569  0.041574153  0.250555387  0.0296889127
## P    -0.1996644443  0.09423571  0.448843233 -0.301507804 -0.1550209020
## pH   -0.0655055041 -0.05384118  0.149231186  0.029760538 -0.0838195232
## K    -0.0715343807  0.34619362 -0.070901080  0.320519489  0.1579888505
## Zn    0.4305014267  0.13918005  0.137839243 -0.074914543  0.2217353906
## Fe    0.0484861298 -0.00656155 -0.098654347 -0.033359941  0.2049552646
## CEC  -0.0458407840  0.05509172 -0.120102755 -0.009776226  0.0934315853
## GWC  -0.0526320922  0.02415569 -0.152890720  0.031967978  0.0083730602
## BD   -0.0333922854 -0.01550855 -0.034077443 -0.014746346  0.0178088928
## POXC -0.0810509006  0.31689341  0.253676726  0.186616853 -0.0268331281
## MWD   0.0595211727  0.07088472 -0.037438296 -0.072046236 -0.1025870882
## Resp -0.0857993822 -0.34285176  0.148453309  0.023611710 -0.3385117980
## MB    0.0999213365  0.08972868  0.041972011  0.023629752  0.1372991755
## GmP   0.1459799821  0.05804830  0.087037572  0.130748260  0.1425292681
## GmN  -0.0007044332 -0.01415210  0.085444213 -0.042679394 -0.0156795861
## Act   0.0419095787 -0.05483353  0.135961449 -0.124329602 -0.0660494732
## AMF   0.0976168464  0.15427297  0.155920381 -0.030454846  0.2216339722
## Fun  -0.1763739606  0.01855137 -0.253324375  0.021944758 -0.1760538498
## FB    0.0106159427  0.01673121  0.117272414  0.040676315  0.0001967716
## bG    0.0778650257  0.14345202 -0.405134621  0.028876732 -0.2412906508
## NAG  -0.5411703374 -0.26884069  0.115903244 -0.041278391  0.1233069281
## AP   -0.3330624297  0.18385906 -0.170690826 -0.422423506  0.4085697417
## ALK   0.1359203422 -0.38967774 -0.006765515  0.002874181  0.2917876112
## ARY   0.0621600837  0.09973028  0.241418384  0.341922009 -0.0830124932
## PHO   0.0219860128  0.39577241  0.021882864 -0.388195498 -0.3482205767
## Pro   0.1868071913 -0.23966938  0.208686539  0.066050983 -0.0611083461
##              PC26         PC27         PC28         PC29         PC30
## Clay -0.155121496 -0.020136104  0.007966507  0.047986823  0.018378772
## TN   -0.416625586 -0.160576980 -0.253588585  0.368218922 -0.490672270
## SOC  -0.151790424 -0.238396514  0.179820828 -0.353878202  0.449693368
## Ca   -0.008867697  0.140075561  0.045863868 -0.026168505 -0.086560755
## Cu   -0.025513283  0.022879125 -0.007923991 -0.064296285  0.140350336
## Mg   -0.215306172  0.019062755  0.023899730  0.109481356 -0.025824264
## Mn   -0.166058247 -0.058138497  0.035504324  0.242013093  0.217619226
## Na    0.110608782  0.050434112 -0.030604029 -0.084162363  0.025203575
## P    -0.281516281  0.169429068  0.112343658  0.086212545  0.088494966
## pH    0.029414209 -0.155110956 -0.470599541  0.350951947  0.455685129
## K     0.234478626  0.156771969 -0.198171296 -0.014034964 -0.027258723
## Zn    0.309024631 -0.166030902  0.154573176  0.160525878  0.030171614
## Fe    0.205985353  0.352293598 -0.318982388  0.212131256  0.208060932
## CEC  -0.025835437  0.151710833  0.028047832 -0.010088930 -0.084474393
## GWC  -0.056193373 -0.056480896 -0.038065845  0.002250257  0.012719808
## BD    0.020994063  0.031382211  0.005022347  0.022028275  0.032460812
## POXC -0.156703396 -0.106182778 -0.060390437  0.001262059  0.103693365
## MWD   0.046934306 -0.066043927 -0.002048996  0.020615364 -0.015235253
## Resp  0.198864069  0.383760333 -0.092378388 -0.162968179 -0.132205705
## MB   -0.050008563 -0.046815116  0.068423000 -0.129555255 -0.023453151
## GmP  -0.143394056 -0.233197339 -0.239658925 -0.085223127  0.008252184
## GmN   0.047797226 -0.004281401 -0.035423186  0.032752940  0.022801016
## Act  -0.020341076  0.023111295 -0.072165330  0.116800573  0.150925943
## AMF  -0.070063977 -0.068326292  0.273417372 -0.001542803 -0.141716471
## Fun   0.049873018  0.085555631 -0.020823180  0.032898800 -0.057035394
## FB   -0.031509901 -0.068856923 -0.120268425 -0.022189853  0.016883927
## bG   -0.061421876  0.075971274  0.101456360  0.192205351  0.029330188
## NAG   0.371406812 -0.325883528  0.253864295  0.246849257  0.005434487
## AP   -0.233442226  0.193010894 -0.140846676 -0.234416189  0.164680502
## ALK  -0.038565095  0.139257124  0.070016053 -0.083557116  0.207623869
## ARY  -0.149405047  0.473697322  0.265938726  0.262891046  0.064532800
## PHO   0.304455453 -0.042083277 -0.176215494 -0.010105646 -0.172113346
## Pro  -0.044340907 -0.052848205 -0.354149787 -0.394863919 -0.176486360
##              PC31         PC32          PC33
## Clay  0.008300792  0.023145261  6.757738e-16
## TN    0.098142090 -0.080647751 -1.358134e-15
## SOC   0.082997736  0.030588336  5.439251e-16
## Ca   -0.142471773  0.007497049  6.625318e-01
## Cu    0.084044637 -0.017336450  2.845596e-16
## Mg   -0.011419024 -0.008943065  1.680908e-01
## Mn   -0.001812666 -0.007614541 -9.761637e-17
## Na    0.009509009 -0.010101456  8.962263e-02
## P    -0.093244936  0.002231558  5.534002e-16
## pH    0.259318468 -0.050027575  8.744273e-16
## K     0.090489006  0.017675871  5.756129e-02
## Zn   -0.126463789  0.046873220  4.818667e-16
## Fe    0.068853773 -0.020144594  3.969150e-16
## CEC  -0.124980788  0.004951992 -7.221160e-01
## GWC  -0.048078875  0.027665023  2.191872e-17
## BD   -0.014348986 -0.003757943 -1.446555e-16
## POXC -0.051717736  0.001896805  7.915032e-16
## MWD   0.034853434 -0.029588193 -4.015579e-17
## Resp -0.033036015  0.024218509 -2.641921e-16
## MB    0.034214529 -0.845681758  2.697627e-16
## GmP  -0.566298573  0.317954943  4.629905e-16
## GmN  -0.044602259  0.108226784 -8.091862e-18
## Act   0.021901359 -0.023866750  9.716343e-17
## AMF   0.632174479  0.331256221  5.920974e-17
## Fun   0.093923289  0.189990190 -1.906000e-16
## FB   -0.166125500 -0.056532663  1.210911e-16
## bG   -0.070064300 -0.011721540 -3.339182e-16
## NAG  -0.139389527 -0.035920563  3.836405e-16
## AP   -0.038413922  0.041331569 -1.920590e-16
## ALK   0.026634068  0.047119992  2.969075e-16
## ARY  -0.125797136  0.001909223 -5.101834e-18
## PHO  -0.006388057 -0.022461959 -3.721677e-16
## Pro   0.158292862  0.017092847 -6.229820e-16
summary(pc)
## Importance of components:
##                           PC1    PC2     PC3     PC4     PC5     PC6     PC7
## Standard deviation     3.7487 2.2239 1.63276 1.31987 1.13915 1.11973 1.02587
## Proportion of Variance 0.4258 0.1499 0.08078 0.05279 0.03932 0.03799 0.03189
## Cumulative Proportion  0.4258 0.5757 0.65649 0.70928 0.74860 0.78659 0.81849
##                            PC8     PC9   PC10    PC11   PC12    PC13    PC14
## Standard deviation     0.96546 0.85277 0.8385 0.77331 0.6599 0.63861 0.58466
## Proportion of Variance 0.02825 0.02204 0.0213 0.01812 0.0132 0.01236 0.01036
## Cumulative Proportion  0.84673 0.86877 0.8901 0.90819 0.9214 0.93375 0.94411
##                           PC15    PC16   PC17    PC18    PC19    PC20    PC21
## Standard deviation     0.54933 0.50483 0.4666 0.44691 0.38204 0.37434 0.31256
## Proportion of Variance 0.00914 0.00772 0.0066 0.00605 0.00442 0.00425 0.00296
## Cumulative Proportion  0.95325 0.96097 0.9676 0.97362 0.97805 0.98229 0.98525
##                           PC22    PC23    PC24    PC25    PC26    PC27    PC28
## Standard deviation     0.27519 0.27029 0.26142 0.23057 0.22395 0.21056 0.18542
## Proportion of Variance 0.00229 0.00221 0.00207 0.00161 0.00152 0.00134 0.00104
## Cumulative Proportion  0.98755 0.98976 0.99183 0.99344 0.99496 0.99631 0.99735
##                           PC29    PC30    PC31    PC32      PC33
## Standard deviation     0.17850 0.16814 0.14841 0.07305 1.665e-15
## Proportion of Variance 0.00097 0.00086 0.00067 0.00016 0.000e+00
## Cumulative Proportion  0.99831 0.99917 0.99984 1.00000 1.000e+00
plot(pc, type="l")

#------
# Plotting PCA using ggbiplot()
#------

ggbiplot(pc)

#------
# Custmoize ggbiplot
#------
# choices = Visualize other PCA components
# obs.scale, var.scale = scale factor to apply to observations and variables
# circle = draw a correlation circle? (only applies when prcomp was called with scale = TRUE and when var.scale = 1)
# ellipse = Draw a normal ellipse for each group              
# group = optional factor variable indicating the groups that the observations belong to. If provided the points will be colored according to groups
# labels = Add labels to plot
# alpha = transparency level for the points
# varname.size = size of the text for variable names
# varname.abbrev = Whether to abbreviate variable names or not.
# var.axes = Add or Remove arrows
#------

bplot = ggbiplot(pcobj = pc, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$location) +
          xlab ("PC1 (42.6%)") + ylab ("PC2 (15.0%)")

bplot2 = bplot + labs(colour = "Locations") + theme_James()+ theme(legend.position = c(0.12,0.7))
bplot2

2.5 Less variables- Biologicals

#names(data)


dataless <- data %>%
  dplyr::select(-Ca, -Cu, -Mg, -Mn, -Zn, -K, -Na, -Fe, -Clay, -P, -BD, -POXC, -FB, -TN, -CEC, -SOC, -GWC, -pH, -MWD)


names(dataless)
##  [1] "sample_pca" "location"   "treatment"  "Resp"       "MB"        
##  [6] "GmP"        "GmN"        "Act"        "AMF"        "Fun"       
## [11] "bG"         "NAG"        "AP"         "ALK"        "ARY"       
## [16] "PHO"        "Pro"

2.6 Less PCA- subset by location

#------
# Principal component analysis
#------

require(stats)
pcless <- prcomp(x = dataless[, -(1:3)],       # Give response variable range
             center = TRUE, 
             scale. = TRUE)
print(pcless)
## Standard deviations (1, .., p=14):
##  [1] 3.09709720 1.11135757 0.89461020 0.77813578 0.72524018 0.59465040
##  [7] 0.51584079 0.44518034 0.34749999 0.29798465 0.28959127 0.25658002
## [13] 0.23309161 0.09803939
## 
## Rotation (n x k) = (14 x 14):
##             PC1         PC2         PC3         PC4          PC5         PC6
## Resp -0.2734212 -0.08636836  0.02553070 -0.32320283  0.391327491 -0.42174302
## MB   -0.3044981  0.26004702  0.03200824  0.05963233  0.002660584 -0.10651906
## GmP  -0.2937375  0.26052945  0.05066433 -0.05849429 -0.090654761 -0.21896469
## GmN  -0.2141527  0.26585240  0.14873539  0.63115896  0.601012206  0.16231143
## Act  -0.2234559  0.26716293  0.43165845 -0.49998830 -0.084451250  0.45878284
## AMF  -0.2972438  0.16896380 -0.01357603 -0.21505939  0.098517220 -0.20151082
## Fun  -0.2412742  0.40460289  0.06906523  0.23015944 -0.448747170  0.11574579
## bG   -0.2522712 -0.39374791  0.23795834 -0.10496897  0.235166659  0.32683788
## NAG  -0.2898857 -0.26262274  0.16174311  0.10725859 -0.186998680 -0.14738549
## AP   -0.2835436 -0.31281142  0.05165916  0.01933015  0.018065097 -0.12442666
## ALK  -0.2417553 -0.07881716 -0.60351957 -0.06473320  0.062731129  0.53277477
## ARY  -0.2849819 -0.01156188 -0.29075602  0.12119165 -0.260477253 -0.18926528
## PHO  -0.2801822 -0.01510581 -0.43742468 -0.10090492  0.038974002  0.02219369
## Pro  -0.2400941 -0.44079650  0.23829030  0.29838289 -0.308722047  0.08843216
##              PC7         PC8         PC9        PC10         PC11        PC12
## Resp  0.25334597 -0.28404327  0.42889030 -0.19718358  0.198767644 -0.21361504
## MB    0.13105813  0.16802096 -0.01914334 -0.06089883 -0.129030936 -0.06834550
## GmP   0.05583222  0.27319477 -0.15628278 -0.05147745 -0.649024457 -0.24007300
## GmN  -0.21409081 -0.09839850  0.03969721 -0.01249993  0.014439612  0.03483353
## Act  -0.39705089 -0.23729377  0.07889811 -0.05585277 -0.004087142 -0.03351346
## AMF  -0.01387628  0.42400361 -0.07978836 -0.06072749  0.238923574  0.40217932
## Fun   0.51443561 -0.19669760  0.05773202  0.20663672  0.345867922 -0.04473728
## bG    0.31436479  0.31083980 -0.43874228  0.02655560  0.235402509 -0.03534666
## NAG  -0.08216731 -0.09762566  0.23601994  0.15750263 -0.175591556  0.71310658
## AP    0.05105242 -0.53173723 -0.39665047  0.28858372 -0.239081314 -0.10861216
## ALK   0.23410573 -0.09650661  0.18043836 -0.28040664 -0.265563792  0.14707048
## ARY  -0.38818496 -0.17179301 -0.38231188 -0.48576675  0.319626299 -0.04055784
## PHO  -0.34139728  0.17934341  0.13995805  0.66891036  0.171441047 -0.22662538
## Pro  -0.13028170  0.26852622  0.41221592 -0.18511231  0.013843895 -0.36024381
##              PC13         PC14
## Resp  0.160653637 -0.054977256
## MB   -0.120058222  0.859363731
## GmP   0.271640628 -0.355256460
## GmN   0.013429755 -0.128705624
## Act  -0.007638937  0.016124621
## AMF  -0.555319389 -0.262892239
## Fun   0.047414230 -0.179802610
## bG    0.324633926  0.029245467
## NAG   0.333918896  0.070635944
## AP   -0.455369263 -0.024914287
## ALK  -0.098825360 -0.043664873
## ARY   0.222605849  0.008001439
## PHO   0.143312147  0.026478604
## Pro  -0.266482625 -0.069718442
summary(pcless)
## Importance of components:
##                           PC1     PC2     PC3     PC4     PC5     PC6     PC7
## Standard deviation     3.0971 1.11136 0.89461 0.77814 0.72524 0.59465 0.51584
## Proportion of Variance 0.6851 0.08822 0.05717 0.04325 0.03757 0.02526 0.01901
## Cumulative Proportion  0.6851 0.77337 0.83053 0.87378 0.91135 0.93661 0.95562
##                            PC8     PC9    PC10    PC11   PC12    PC13    PC14
## Standard deviation     0.44518 0.34750 0.29798 0.28959 0.2566 0.23309 0.09804
## Proportion of Variance 0.01416 0.00863 0.00634 0.00599 0.0047 0.00388 0.00069
## Cumulative Proportion  0.96977 0.97840 0.98474 0.99073 0.9954 0.99931 1.00000
plot(pcless, type="l")

#------
# Plotting PCA using ggbiplot()
#------

ggbiplot(pcless)

#------
# Custmoize ggbiplot
#------
# choices = Visualize other PCA components
# obs.scale, var.scale = scale factor to apply to observations and variables
# circle = draw a correlation circle? (only applies when prcomp was called with scale = TRUE and when var.scale = 1)
# ellipse = Draw a normal ellipse for each group              
# group = optional factor variable indicating the groups that the observations belong to. If provided the points will be colored according to groups
# labels = Add labels to plot
# alpha = transparency level for the points
# varname.size = size of the text for variable names
# varname.abbrev = Whether to abbreviate variable names or not.
# var.axes = Add or Remove arrows
#------

bplotl = ggbiplot(pcobj = pcless, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 #labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$location) +
          xlab ("PC1 (68.5%)") + ylab ("PC2 (8.8%)") + 
  labs(colour = "Locations") + 
  theme_James()+ theme(legend.position = c(0.12,0.8))

bplotl

ggsave("locationbiplot1.png",  height=6, width=9)

2.7 Less PCA- subset by land use

#------
# Principal component analysis
#------

require(stats)
pcless <- prcomp(x = dataless[, -(1:3)],       # Give response variable range
             center = TRUE, 
             scale. = TRUE)
print(pcless)
## Standard deviations (1, .., p=14):
##  [1] 3.09709720 1.11135757 0.89461020 0.77813578 0.72524018 0.59465040
##  [7] 0.51584079 0.44518034 0.34749999 0.29798465 0.28959127 0.25658002
## [13] 0.23309161 0.09803939
## 
## Rotation (n x k) = (14 x 14):
##             PC1         PC2         PC3         PC4          PC5         PC6
## Resp -0.2734212 -0.08636836  0.02553070 -0.32320283  0.391327491 -0.42174302
## MB   -0.3044981  0.26004702  0.03200824  0.05963233  0.002660584 -0.10651906
## GmP  -0.2937375  0.26052945  0.05066433 -0.05849429 -0.090654761 -0.21896469
## GmN  -0.2141527  0.26585240  0.14873539  0.63115896  0.601012206  0.16231143
## Act  -0.2234559  0.26716293  0.43165845 -0.49998830 -0.084451250  0.45878284
## AMF  -0.2972438  0.16896380 -0.01357603 -0.21505939  0.098517220 -0.20151082
## Fun  -0.2412742  0.40460289  0.06906523  0.23015944 -0.448747170  0.11574579
## bG   -0.2522712 -0.39374791  0.23795834 -0.10496897  0.235166659  0.32683788
## NAG  -0.2898857 -0.26262274  0.16174311  0.10725859 -0.186998680 -0.14738549
## AP   -0.2835436 -0.31281142  0.05165916  0.01933015  0.018065097 -0.12442666
## ALK  -0.2417553 -0.07881716 -0.60351957 -0.06473320  0.062731129  0.53277477
## ARY  -0.2849819 -0.01156188 -0.29075602  0.12119165 -0.260477253 -0.18926528
## PHO  -0.2801822 -0.01510581 -0.43742468 -0.10090492  0.038974002  0.02219369
## Pro  -0.2400941 -0.44079650  0.23829030  0.29838289 -0.308722047  0.08843216
##              PC7         PC8         PC9        PC10         PC11        PC12
## Resp  0.25334597 -0.28404327  0.42889030 -0.19718358  0.198767644 -0.21361504
## MB    0.13105813  0.16802096 -0.01914334 -0.06089883 -0.129030936 -0.06834550
## GmP   0.05583222  0.27319477 -0.15628278 -0.05147745 -0.649024457 -0.24007300
## GmN  -0.21409081 -0.09839850  0.03969721 -0.01249993  0.014439612  0.03483353
## Act  -0.39705089 -0.23729377  0.07889811 -0.05585277 -0.004087142 -0.03351346
## AMF  -0.01387628  0.42400361 -0.07978836 -0.06072749  0.238923574  0.40217932
## Fun   0.51443561 -0.19669760  0.05773202  0.20663672  0.345867922 -0.04473728
## bG    0.31436479  0.31083980 -0.43874228  0.02655560  0.235402509 -0.03534666
## NAG  -0.08216731 -0.09762566  0.23601994  0.15750263 -0.175591556  0.71310658
## AP    0.05105242 -0.53173723 -0.39665047  0.28858372 -0.239081314 -0.10861216
## ALK   0.23410573 -0.09650661  0.18043836 -0.28040664 -0.265563792  0.14707048
## ARY  -0.38818496 -0.17179301 -0.38231188 -0.48576675  0.319626299 -0.04055784
## PHO  -0.34139728  0.17934341  0.13995805  0.66891036  0.171441047 -0.22662538
## Pro  -0.13028170  0.26852622  0.41221592 -0.18511231  0.013843895 -0.36024381
##              PC13         PC14
## Resp  0.160653637 -0.054977256
## MB   -0.120058222  0.859363731
## GmP   0.271640628 -0.355256460
## GmN   0.013429755 -0.128705624
## Act  -0.007638937  0.016124621
## AMF  -0.555319389 -0.262892239
## Fun   0.047414230 -0.179802610
## bG    0.324633926  0.029245467
## NAG   0.333918896  0.070635944
## AP   -0.455369263 -0.024914287
## ALK  -0.098825360 -0.043664873
## ARY   0.222605849  0.008001439
## PHO   0.143312147  0.026478604
## Pro  -0.266482625 -0.069718442
summary(pcless)
## Importance of components:
##                           PC1     PC2     PC3     PC4     PC5     PC6     PC7
## Standard deviation     3.0971 1.11136 0.89461 0.77814 0.72524 0.59465 0.51584
## Proportion of Variance 0.6851 0.08822 0.05717 0.04325 0.03757 0.02526 0.01901
## Cumulative Proportion  0.6851 0.77337 0.83053 0.87378 0.91135 0.93661 0.95562
##                            PC8     PC9    PC10    PC11   PC12    PC13    PC14
## Standard deviation     0.44518 0.34750 0.29798 0.28959 0.2566 0.23309 0.09804
## Proportion of Variance 0.01416 0.00863 0.00634 0.00599 0.0047 0.00388 0.00069
## Cumulative Proportion  0.96977 0.97840 0.98474 0.99073 0.9954 0.99931 1.00000
plot(pcless, type="l")

#------
# Plotting PCA using ggbiplot()
#------

ggbiplot(pcless)

#------
# Custmoize ggbiplot
#------
# choices = Visualize other PCA components
# obs.scale, var.scale = scale factor to apply to observations and variables
# circle = draw a correlation circle? (only applies when prcomp was called with scale = TRUE and when var.scale = 1)
# ellipse = Draw a normal ellipse for each group              
# group = optional factor variable indicating the groups that the observations belong to. If provided the points will be colored according to groups
# labels = Add labels to plot
# alpha = transparency level for the points
# varname.size = size of the text for variable names
# varname.abbrev = Whether to abbreviate variable names or not.
# var.axes = Add or Remove arrows
#------
# Group by land use

bplotlu = ggbiplot(pcobj = pcless, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 #labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$treatment) +
          xlab ("PC1 (68.5%)") + ylab ("PC2 (8.8%)") + 
  labs(colour = "Locations") + 
  theme_James()+ theme(legend.position = c(0.12,0.8))
bplotlu

ggsave("landusebiplot1.png",  height=6, width=9)


#Group by Depth

bplotlud = ggbiplot(pcobj = pcless, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 #labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$treatment) +
          xlab ("PC1 (68.5%)") + ylab ("PC2 (8.8%)") + 
  labs(colour = "Locations") + 
  theme_James()+ theme(legend.position = c(0.12,0.8))
bplotlud

ggsave("landusebiplot2.png",  height=6, width=9)

2.8 Less PCA- subset by land use- with C and N

#------
# Principal component analysis
#------

cndataless <- data %>%
  dplyr::select(-Ca, -Cu, -Mg, -Mn, -Zn, -K, -Na, -Fe, -Clay, -P, -BD, -POXC, -FB, -CEC, -GWC, -pH, -MWD)


require(stats)
cnpcless <- prcomp(x = cndataless[, -(1:3)],       # Give response variable range
             center = TRUE, 
             scale. = TRUE)
print(cnpcless)
## Standard deviations (1, .., p=16):
##  [1] 3.34507754 1.16758090 0.89668490 0.78195056 0.73561526 0.60688534
##  [7] 0.51718446 0.45015074 0.43750248 0.32630463 0.31058678 0.29288299
## [13] 0.26018798 0.22961615 0.20692969 0.09378996
## 
## Rotation (n x k) = (16 x 16):
##             PC1         PC2         PC3          PC4          PC5         PC6
## TN   -0.2716862 -0.25070261  0.02679830 -0.042047039  0.141885082 -0.05555664
## SOC  -0.2711168 -0.17511352  0.06271726 -0.102294520  0.091323133 -0.23041276
## Resp -0.2555447 -0.05797849 -0.03190335  0.287174582  0.412046917 -0.36107338
## MB   -0.2773827  0.28673909 -0.02473236 -0.064195239  0.002315997 -0.09200401
## GmP  -0.2668590  0.29090241 -0.04688203  0.059240881 -0.070705688 -0.20570797
## GmN  -0.1962753  0.25461945 -0.11926155 -0.683955513  0.522544135  0.22769078
## Act  -0.1998612  0.30946765 -0.43553735  0.490306189 -0.014003416  0.37630432
## AMF  -0.2721379  0.19975597  0.01403029  0.201077251  0.119890546 -0.18899968
## Fun  -0.2154123  0.42796032 -0.05914343 -0.198112319 -0.442828069  0.08183075
## bG   -0.2372788 -0.32229892 -0.26782185  0.122930913  0.167120948  0.39919625
## NAG  -0.2711882 -0.20041080 -0.18255487 -0.070545445 -0.226842973 -0.11502605
## AP   -0.2666156 -0.25584614 -0.07478563  0.007246757 -0.027221564 -0.05629380
## ALK  -0.2247710 -0.05067622  0.58524432  0.105918979  0.005086819  0.55978669
## ARY  -0.2630274  0.02924389  0.27932291 -0.076557165 -0.295546438 -0.16269843
## PHO  -0.2601746  0.01065150  0.42698130  0.120257212  0.019915447  0.03910076
## Pro  -0.2279692 -0.37361691 -0.26536223 -0.241059038 -0.380951601  0.09841406
##               PC7         PC8         PC9         PC10        PC11
## TN    0.041831525 -0.26584889  0.36369449 -0.113078098  0.32678364
## SOC   0.091990365 -0.14218466  0.58078861 -0.334949657 -0.27315194
## Resp -0.287816919 -0.22854610 -0.14638336  0.465386817 -0.27435077
## MB   -0.140520331  0.16656452  0.02555178  0.002984395  0.03111478
## GmP  -0.076262839  0.27535928 -0.02585816 -0.030838333  0.39986130
## GmN   0.199940106 -0.03797115 -0.14674511  0.084654223 -0.03478460
## Act   0.442280842 -0.28220770  0.08800876  0.012318537 -0.07314555
## AMF  -0.004575324  0.43339535  0.06561762 -0.090363051 -0.17488999
## Fun  -0.484131136 -0.27424844  0.13922444 -0.047448953 -0.02781797
## bG   -0.328276090  0.40244616 -0.12987467 -0.351624452 -0.09193702
## NAG   0.057650283 -0.04014645 -0.15171192  0.349038185  0.10333758
## AP   -0.087357313 -0.38202394 -0.47652359 -0.328938398  0.30170856
## ALK  -0.210913264 -0.10565783  0.04640694  0.209207557 -0.12783021
## ARY   0.350450662 -0.02017160 -0.40149586 -0.258667401 -0.47878815
## PHO   0.329600259  0.18183973  0.01151114  0.122825217  0.41930071
## Pro   0.129377760  0.23458106  0.15572024  0.400389516 -0.11403281
##               PC12        PC13          PC14         PC15         PC16
## TN   -0.1244567451 -0.16264754 -0.0741813884  0.673044811  0.113672866
## SOC   0.0002275771  0.17240234 -0.0771203833 -0.474441763 -0.080254680
## Resp  0.0821417058 -0.27673246 -0.0948385074 -0.055666359 -0.062588291
## MB   -0.1402871622 -0.02653569  0.1284941494 -0.132076326  0.850986229
## GmP  -0.5507891024 -0.12548307 -0.2596796489 -0.166773885 -0.365554997
## GmN   0.0238743762  0.02660943  0.0010070240  0.002307228 -0.130837032
## Act  -0.0377191728 -0.01758994 -0.0003910409 -0.045332124  0.010144894
## AMF   0.1391670623  0.32293078  0.5186107139  0.341929107 -0.234265896
## Fun   0.3799873407 -0.10010949 -0.0495261672  0.083976890 -0.170255741
## bG    0.1727496084 -0.09244396 -0.3284539737  0.004213954  0.026810380
## NAG   0.0760499453  0.70166269 -0.3406487647  0.062474086  0.069166466
## AP   -0.0232651834  0.04354947  0.4689055367 -0.221568094 -0.051224715
## ALK  -0.3383644248  0.18365574  0.0978632487 -0.036143172 -0.052723161
## ARY  -0.0931718782 -0.19559102 -0.2371709143  0.218122632  0.030460205
## PHO   0.5669863167 -0.18217054 -0.0803579896 -0.198904600  0.009038373
## Pro  -0.0902843024 -0.35710530  0.3288148682 -0.077918359 -0.076860679
summary(cnpcless)
## Importance of components:
##                           PC1    PC2     PC3     PC4     PC5     PC6     PC7
## Standard deviation     3.3451 1.1676 0.89668 0.78195 0.73562 0.60689 0.51718
## Proportion of Variance 0.6994 0.0852 0.05025 0.03822 0.03382 0.02302 0.01672
## Cumulative Proportion  0.6994 0.7845 0.83480 0.87302 0.90684 0.92986 0.94657
##                            PC8     PC9    PC10    PC11    PC12    PC13   PC14
## Standard deviation     0.45015 0.43750 0.32630 0.31059 0.29288 0.26019 0.2296
## Proportion of Variance 0.01266 0.01196 0.00665 0.00603 0.00536 0.00423 0.0033
## Cumulative Proportion  0.95924 0.97120 0.97786 0.98389 0.98925 0.99348 0.9968
##                           PC15    PC16
## Standard deviation     0.20693 0.09379
## Proportion of Variance 0.00268 0.00055
## Cumulative Proportion  0.99945 1.00000
plot(cnpcless, type="l")

#------
# Plotting PCA using ggbiplot()
#------

ggbiplot(cnpcless)

#------
# Custmoize ggbiplot
#------
# choices = Visualize other PCA components
# obs.scale, var.scale = scale factor to apply to observations and variables
# circle = draw a correlation circle? (only applies when prcomp was called with scale = TRUE and when var.scale = 1)
# ellipse = Draw a normal ellipse for each group              
# group = optional factor variable indicating the groups that the observations belong to. If provided the points will be colored according to groups
# labels = Add labels to plot
# alpha = transparency level for the points
# varname.size = size of the text for variable names
# varname.abbrev = Whether to abbreviate variable names or not.
# var.axes = Add or Remove arrows
#------
# Group by land use

bplotlucn = ggbiplot(pcobj = cnpcless, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 #labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$treatment) +
          xlab ("PC1 (69.9%)") + ylab ("PC2 (8.5%)") + 
  labs(colour = "Locations") + 
  theme_James()+ theme(legend.position = c(0.12,0.8))

ggsave("cnlandusebiplot1.png",  height=6, width=9)


#Group by Depth

bplotludcn = ggbiplot(pcobj = cnpcless, 
                 choices = c(1,2),
                 obs.scale = 1, var.scale = 1,
                 #labels = data$treatment,
                 varname.size = 3,
                 varname.abbrev = FALSE,
                 var.axes = TRUE,
                 circle = TRUE,
                 ellipse = TRUE, groups = data$treatment) +
          xlab ("PC1 (69.9%)") + ylab ("PC2 (8.5%)") + 
  labs(colour = "Locations") + 
  theme_James()+ theme(legend.position = c(0.12,0.8))
bplotludcn

ggsave("cnlandusebiplot6.png",  height=6, width=9)

ggsave("cnbiplotall.png",  height=6, width=9)