add nextflow d30e48d

nextflow/tests/blast-parallel.nf

@@ -0,0 +1,66 @@
+#!/usr/bin/env nextflow
+
+params.db = "$baseDir/blast-db/tiny"
+params.query = "$baseDir/data/sample.fa"
+params.chunk = 1 
+
+/* 
+ * Extends a BLAST query for each entry in the 'chunks' channel 
+ */
+process blast {
+    input:
+    path 'query.fa'
+    val db
+
+    output:
+    path 'top_hits'
+
+    script:
+    """
+    blastp -db ${db} -query query.fa -outfmt 6 > blast_result
+    cat blast_result | head -n 10 | cut -f 2 > top_hits
+    """
+}
+
+/*
+ * Find out the top 10 matches returned by the BLAST query
+ */ 
+process extract {
+    input:
+    path 'top_hits'
+    path db
+
+    output:
+    path 'sequences'
+
+    script:
+    "blastdbcmd -db ${db} -entry_batch top_hits | head -n 10 > sequences"
+}
+
+
+/*
+ * Aligns a T-Coffee MSA and print it 
+ */
+process align {
+    debug true
+
+    input:
+    path all_seq
+
+    script:
+    "t_coffee $all_seq 2>/dev/null | tee align_result"
+}
+
+/*
+ * main flow
+ */
+workflow {
+    ch_fasta = channel.fromPath(params.query)
+        | splitFasta(by: params.chunk, file:true)
+
+    ch_sequences = blast(ch_fasta, params.db)
+
+    extract(ch_sequences, params.db)
+        | collectFile(name:'all_seq') // Collect all hits to a single file called  'all_seq'
+        | align
+}