I wrote a function in R, which parses arguments from a dataframe, and outputs the old dataframe + a new column with stats from each row.
I get the following warning:
Warning message:
In [[.data.frame(xx, sxx[j]) :
named arguments other than 'exact' are discouraged
I am not sure what this means, to be honest. I did spot checks on the results and seem OK to me. The function itself is quite long, I will post it if needed to better answer the question. Edit:
This is a sample dataframe:
my_df<- data.frame('ALT'= c('A,C', 'A,G'),
'Sample1'= c('1/1:35,3,0,35,3,35:1:1:0:0,1,0', './.:0,0,0,0,0,0:0:0:0:0,0,0'),
'Sample2'= c('2/2:188,188,188,33,33,0:11:11:0:0,0,11', '1/1:255,99,0,255,99,255:33:33:0:0,33,0'),
'Sample3'= c('1/1:219,69,0,219,69,219:23:23:0:0,23,0', '0/1:36,0,78,48,87,120:7:3:0:4,3,0'))
And this is the function:
multi_allelic_filter_v2<- function(in_vcf, start_col, end_col, threshold=1){
#input: must have gone through biallelic_assessment first
table0<- in_vcf
#ALT_alleles is the number of alt alleles with coverage > threshold across samples
#The following function calculates coverage across samples for a single allele
single_allele_tot_cov_count<- function(list_of_unparsed_cov,
allele_pos){
single_allele_coverage_count<- 0
for (i in 1:length(list_of_unparsed_cov)) { # i is each group of coverages/sample
single_allele_coverage_count<- single_allele_coverage_count+
as.numeric(strsplit(as.character(list_of_unparsed_cov[i]),
split= ',')[[1]])[allele_pos]}
return(single_allele_coverage_count)}
#single row function
#Now we need to reiterate on each ALT allele in the row
single_row_assessment<- function(single_row){
# No. of alternative alleles over threshold
alt_alleles0 <- 0
if (single_row$is_biallelic==TRUE){
alt_alleles0<- 1
} else {
alt_coverages <- numeric() #coverages across sample of each ALT allele
altcovs_unparsed<- character() #Unparsed coverages from each sample
for (i in start_col:end_col) {
#Let's fill altcovs_unparsed
altcovs_unparsed<- c(altcovs_unparsed,
strsplit(x = as.character(single_row[1,i]), split = ':')[[1]][6])}
#Now let's calculate alt_coverages
for (i in 1:lengths(strsplit(as.character(
single_row$ALT),',',fixed = TRUE))) {
alt_coverages<- c(alt_coverages, single_allele_tot_cov_count(
list_of_unparsed_cov = altcovs_unparsed, allele_pos = i+1))}
#Now, let's see how many ALT alleles are over threshold
alt_alleles0<- sum(alt_coverages>threshold)}
return(alt_alleles0)}
#Now, let's reiterate across each row:
#ALT_alleles is no. of alt alleles with coverage >threshold across samples
table0$ALT_alleles<- -99 # Just as a marker, to make sure function works
for (i in 1:nrow(table0)){
table0[i,'ALT_alleles'] <- single_row_assessment(single_row = table0[i,])}
#Now we now how many ALT alleles >= threshold coverage are in each SNP
return(table0)}
Basically, in the following line: '1/1:219,69,0,219,69,219:23:23:0:0,23,0' fields are separated by ":", and I am interested in the last two numbers of the last field (23 and 0); in each row I want to sum all the numbers in those positions (two separate sums), and output how many of the "sums" are over a threshold. Hope it makes sense...
