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install.packages("vcfR", 
                 repos = "https://cloud.r-project.org")
## 
## The downloaded binary packages are in
##  /var/folders/hn/6wgsl4wd7pv6vl38d9t06tnr0000gn/T//RtmpVM5WVZ/downloaded_packages
library(vcfR)
## 
##    *****       ***   vcfR   ***       *****
##    This is vcfR 1.13.0 
##      browseVignettes('vcfR') # Documentation
##      citation('vcfR') # Citation
##    *****       *****      *****       *****
library(vegan)
## Loading required package: permute
## Loading required package: lattice
## This is vegan 2.6-4
library(ggplot2)
library(ggpubr)
getwd()
## [1] "/Users/adetayoadenekan/Downloads"
list.files(pattern="vcf")
##  [1] "1.159051856-159301856.ALL.chr1_GRCh38.genotypes.20170504.vcf.gz"
##  [2] "11.47816134-48056134.ALL.chr11_GRCh38.genotypes.20170504.vcf.gz"
##  [3] "2.136483646-136733646.ALL.chr2_GRCh38.genotypes.20170504.vcf.gz"
##  [4] "all_loci-1.vcf"                                                 
##  [5] "all_loci.vcf"                                                   
##  [6] "code_checkpoint_vcfR.html"                                      
##  [7] "code_checkpoint_vcfR.Rmd"                                       
##  [8] "my_final_genomes.vcf.gz"                                        
##  [9] "vcf_num_df.csv"                                                 
## [10] "vcf_num_df2.csv"                                                
## [11] "vcf_num.csv"                                                    
## [12] "vcf_scaled.csv"                                                 
## [13] "vcf-num_df.csv"                                                 
## [14] "vcfR_test.vcf"                                                  
## [15] "vcfR_test.vcf.gz"
my_vcf<-"my_final_genomes.vcf.gz" 

vcf<-vcfR::read.vcfR(my_vcf, convertNA=T)
## Scanning file to determine attributes.
## File attributes:
##   meta lines: 130
##   header_line: 131
##   variant count: 6238
##   column count: 2513
## 
Meta line 130 read in.
## All meta lines processed.
## gt matrix initialized.
## Character matrix gt created.
##   Character matrix gt rows: 6238
##   Character matrix gt cols: 2513
##   skip: 0
##   nrows: 6238
##   row_num: 0
## 
Processed variant 1000
Processed variant 2000
Processed variant 3000
Processed variant 4000
Processed variant 5000
Processed variant 6000
Processed variant: 6238
## All variants processed
vcf_num<- vcfR::extract.gt(vcf, element="GT", IDtoRowNames= F,
                            as.numeric=T, convertNA=T)
write.csv(vcf_num, file="vcf_num.csv", row.names=F)
list.files(pattern="vcf_num")
## [1] "vcf_num_df.csv"  "vcf_num_df2.csv" "vcf_num.csv"
vcf_num_t<-t(vcf_num)
vcf_num_df<- data.frame(vcf_num_t)
sample<- row.names(vcf_num_df)

vcf_num_df<- data.frame(sample, vcf_num_df)
getwd()
## [1] "/Users/adetayoadenekan/Downloads"
write.csv(vcf_num_df, file="vcf_num_df.csv", row.names=F)
list.files(pattern="vcf_num_df.csv")
## [1] "vcf_num_df.csv"
pop_meta <- read.csv(file = "1000genomes_people_info2-1.csv")
names(pop_meta)
## [1] "pop"       "super_pop" "sample"    "sex"       "lat"       "lng"
names(vcf_num_df)[1:10]
##  [1] "sample" "X1"     "X2"     "X3"     "X4"     "X5"     "X6"     "X7"    
##  [9] "X8"     "X9"
vcf_num_df2 <- merge(pop_meta, 
                     vcf_num_df,
                     by = "sample")
nrow(vcf_num_df) == nrow(vcf_num_df2)
## [1] TRUE
names(vcf_num_df2)[1:15]
##  [1] "sample"    "pop"       "super_pop" "sex"       "lat"       "lng"      
##  [7] "X1"        "X2"        "X3"        "X4"        "X5"        "X6"       
## [13] "X7"        "X8"        "X9"
getwd()
## [1] "/Users/adetayoadenekan/Downloads"
write.csv(vcf_num_df2, file="vcf_num_df2.csv", row.names=F)

list.files(pattern= "vcf_num_df2.csv")
## [1] "vcf_num_df2.csv"
invar_omit<-function(x){
  cat("Dataframe of dim", dim(x), "processed...\n")
  sds<-apply(x,2,sd,na.rm=T)
  i_var0<- which(sds==0)
}
invar_omit <- function(x){
  cat("Dataframe of dim",dim(x), "processed...\n")
  sds <- apply(x, 2, sd, na.rm = TRUE)
  i_var0 <- which(sds == 0)
 
  
  cat(length(i_var0),"columns removed\n")
  
  if(length(i_var0) > 0){
     x <- x[, -i_var0]
  }
  
  ## add return()  with x in it
  return(x) 
}
names(vcf_num_df2)[1:10]
##  [1] "sample"    "pop"       "super_pop" "sex"       "lat"       "lng"      
##  [7] "X1"        "X2"        "X3"        "X4"
vcf_noinvar <- vcf_num_df2
vcf_noinvar[, -c(1:6)] <- invar_omit(vcf_noinvar[, -c(1:6)])
## Dataframe of dim 2504 6238 processed...
## 1719 columns removed
my_meta_N_invar_cols <- 1719
find_NAs <- function(x){
  NAs_TF <- is.na(x)
  i_NA <- which(NAs_TF == TRUE)
  N_NA <- length(i_NA)
  
  return(i_NA)
}
N_rows <- nrow(vcf_noinvar)
N_NA <- rep(x = 0, times = N_rows)
N_SNPs <- ncol(vcf_noinvar)
for(i in 1:N_rows){
  i_NA <- find_NAs(vcf_noinvar[i,])
  N_NA_i <- length(i_NA)
  N_NA[i] <- N_NA_i
}
cutoff50 <- N_SNPs*0.5
percent_NA <- N_NA/N_SNPs*100
any(percent_NA > 50)
## [1] FALSE
my_meta_N_meanNA_rows <- mean(percent_NA)

mean_imputation <- function(df){
  cat("This may take some time...")
  n_cols <- ncol(df)
  for(i in 1:n_cols){
    column_i <- df[,i]
    mean_i <- mean(column_i, na.rm = TRUE)
    NAs_i <- which(is.na(column_i))
    N_NAs <- length(NAs_i)
    column_i[NAs_i] <- mean_i
    df[,i] <- column_i
  }
  return(df)
}
names(vcf_noinvar)[1:10]
##  [1] "sample"    "pop"       "super_pop" "sex"       "lat"       "lng"      
##  [7] "X1"        "X2"        "X3"        "X4"
vcf_noNA<- vcf_noinvar
vcf_noNA[,-c(1:6)]<- mean_imputation(vcf_noinvar[,-c(1:6)])
## This may take some time...
vcf_scaled <- vcf_noNA
vcf_scaled[,-c(1:6)] <- scale(vcf_noNA[,-c(1:6)])


write.csv(vcf_scaled, file = "vcf_scaled.csv",
          col.names = F)
## Warning in write.csv(vcf_scaled, file = "vcf_scaled.csv", col.names = F):
## attempt to set 'col.names' ignored
vcf_pca <- prcomp(vcf_scaled[,-c(1:6)])

screeplot(vcf_pca)

PCA_variation <- function(pca_summary, PCs = 2){
  var_explained <- pca_summary$importance[2,1:PCs]*100
  var_explained <- round(var_explained, 3)
  return(var_explained)
}
PCA_variation <- function(pca_summary, PCs = 2){
  var_explained <- pca_summary$importance[2,1:PCs]*100
  var_explained <- round(var_explained, 3)
  return(var_explained)
}
vcf_pca_summary <- summary(vcf_pca)
var_out <- PCA_variation(vcf_pca_summary, PCs = 500)



N_columns <- ncol(vcf_scaled)
cut_off <- 1/N_columns*100
i_cut_off <- which(var_out < cut_off)
i_cut_off <- min(i_cut_off)
## Warning in min(i_cut_off): no non-missing arguments to min; returning Inf
my_meta_N_meanNA_rowsPCs <- i_cut_off
my_meta_var_PC123 <- var_out[c(1,2,3)]
barplot(var_out,
        main = "Percent variation (%) Scree plot",
        ylab = "Percent variation (%) explained",
        names.arg = 1:length(var_out))
abline(h = cut_off, col = 2, lwd = 2)
abline(v = i_cut_off)
legend("topright",
       col = c(2,1),
       lty = c(1,1),
       legend = c("Vertical line: cutoff",
                  "Horizontal line: 1st value below cut off"))

cumulative_variation <- cumsum(var_out)
plot(cumulative_variation)

vcf_pca_scores <- vegan::scores(vcf_pca)
vcf_pca_scores2 <- data.frame(super_pop = vcf_noNA$super_pop, vcf_pca_scores)

my_meta_var_PC123[1]
##   PC1 
## 2.891
my_meta_var_PC123[2]
##   PC2 
## 2.659
ggpubr::ggscatter(data = vcf_pca_scores2,
                  y = "PC2",
                  x = "PC1",
                  color = "super_pop",
                  shape = "super_pop",
                  main = "PCA Scatterplot",
                  xlab = "PC1 (1.5% of variation)",
                  ylab = "PC2 (1.1% of variation)")

ggpubr::ggscatter(data = vcf_pca_scores2,
                  y = "PC3",
                  x = "PC2",
                  color = "super_pop",
                  shape = "super_pop",
                  main = "PCA Scatterplot",
                  xlab = "PC2 (1.1% of variation",
                  ylab = "PC3 (1.05% of variation)")

ggpubr::ggscatter(data = vcf_pca_scores2,
                  y = "PC3",
                  x = "PC1",
                  color = "super_pop",
                  shape = "super_pop",
                  main = "PCA Scatterplot",
                  xlab = "PC1 (1.5% of variation)",
                  ylab = "PC3 (1.05% of variation")

ggpubr::ggscatter(data = vcf_pca_scores2,
                  y = "PC3",
                  x = "PC2",
                  color = "super_pop",
                  shape = "super_pop",
                  main = "PCA Scatterplot",
                  xlab = "PC2 (1.1% of variation",
                  ylab = "PC3 (1.05% of variation)")