generate kraken-style report from a blast results
kraken report是一种较直观地物种鉴定结果展示格式，基于 taxonomy-tree LCA溯源，strain的reads_count结果会累加至species level, species reads_count结果会累加至genus level，...
centrifuge-kreport 可将centrifuge结果生成kraken-style report; 在此脚本基础上，实现blast 结果生成kraken-style report脚本blast2kraken.pl的撰写；目的用于将nt库blast比对结果以更直观地方式展示物种鉴定结果，而不必再忧虑鉴定出一堆subgroup/strain物种;
Usage:
Usage: blast2kraken.pl -x <blast result> -q <fasta> -t <taxdb> OPTIONS > <kraken-style.out>
blast2kraken.pl -x <blast result> -t <taxdb> OPTIONS > <kraken-style.out>
blast2kraken.pl creates Kraken-style reports from blast out files.
Options:
-x Blast (REQUIRED) Blast result
-t TaxDB (REQUIRED) Taxdb from taxonomy
-q Fasta Fasta input, to count all sequencing reads
-min-ident Score Require a minimum identity score for reads alignment
-min-length Score Require a minimum lentgh for reads query
注：此脚本适用于blast -outfmt '6 qseqid qlen sseqid sgi slen pident length mismatch gapopen qstart qend sstart send evalue bitscore staxid ssciname'格式的比对结果；
若blast格式不符，可更改脚本中对应项的位置；
my ($readID,$qlen,$seqID,$pident,$taxID)= @arr[0,1,2,5,15] ;
Example结果鉴定物种展示
$less example.blast2kraken.report|awk -F '\t' '$1>1 && $4=="S"{sub(/^[ \t]+|[ ]+$/,"",$NF);print $1"\t"$2"\t"$4"\t"$5"\t"$NF}'|head -5
23.98 29981 S 1280 Staphylococcus aureus
4.00 4996 S 1639 Listeria monocytogenes
3.98 4978 S 1423 Bacillus subtilis
3.96 4946 S 1613 Lactobacillus fermentum
3.95 4936 S 1351 Enterococcus faecalis