taxonomy
lca.py $input1 $out_file1 $rank_bound
**What it does**
This tool identifies the lowest taxonomic rank for which a mategenomic sequencing read is diagnostic. It takes datasets produced by *Fetch Taxonomic Ranks* tool (aka Taxonomy format) as the input.
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**Example**
Suppose you have two reads, **read_1** and **read_2**, with the following taxonomic profiles (scroll sideways to see the entire dataset)::
read_1 1 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum1 subphylum1 superclass1 class1 subclass1 superorder1 order1 suborder1 superfamily1 family1 subfamily1 tribe1 subtribe1 genus1 subgenus1 species1 subspecies1
read_1 2 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum1 subphylum1 superclass1 class1 subclass1 superorder1 order1 suborder1 superfamily1 family1 subfamily1 tribe1 subtribe1 genus2 subgenus2 species2 subspecies2
read_2 3 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum3 subphylum3 superclass3 class3 subclass3 superorder3 order3 suborder3 superfamily3 family3 subfamily3 tribe3 subtribe3 genus3 subgenus3 species3 subspecies3
read_2 4 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum4 subphylum4 superclass4 class4 subclass4 superorder4 order4 suborder4 superfamily4 family4 subfamily4 tribe4 subtribe4 genus4 subgenus4 species4 subspecies4
For **read_1** taxonomic labels are consistent until the genus level, where the taxonomy splits into two branches, one ending with *subspecies1* and the other with *subspecies2*. This implies **that the lowest taxomomic rank read_1 can identify is SUBTRIBE**. Similarly, read_2 is diagnostic up until the **superphylum** level. As a results the output of this tool will be::
read_1 2 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum1 subphylum1 superclass1 class1 subclass1 superorder1 order1 suborder1 superfamily1 family1 subfamily1 tribe1 subtribe1 n n n n
read_2 3 root superkingdom1 kingdom1 subkingdom1 superphylum1 n n n n n n n n n n n n n n n n n
where, **n** means *EMPTY*.
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**What's up with the drop down?**
Why do we need the *require the lowest rank to be at least* dropdown? Let's look at the above example again. Suppose you need to find only those reads that are diagnostic on at least phylum level. To do this you need to set the *require the lowest rank to be at least* to **phylum**. As a result your output will look like this::
read_1 2 root superkingdom1 kingdom1 subkingdom1 superphylum1 phylum1 subphylum1 superclass1 class1 subclass1 superorder1 order1 suborder1 superfamily1 family1 subfamily1 tribe1 subtribe1 n n n n
.. class:: infomark
Note, that **read_2** is now omitted as it matches two phyla (**phylum3** and **phylum4**) and therefore is not diagnostic (but rather cosmopolitan) on *phylum* level.