#!/usr/bin/env python
# coding: utf-8

# This notebook illustrates how to compute pairwise identity between two unaligned sequences. It does this first by aligning the sequences, and then computing the fraction of positions that are identical.

# In[1]:


from skbio import DNA
from skbio.alignment import global_pairwise_align_nucleotide
s1 = DNA("GAGTTTGATCCTGGCTCAGATTGAACGCTGGCGGCATGCTTAACACATGCAAGTCGAACGGCAGCATGACTTAGCTTGCTAAGTTGATGGCGAGTGGCGAACGGGTGAGTAACGCGTAGGAATATGCCTTAAAGAGGGGGACAACTTGGGGAAACTCAAGCTAATACCGCATAAACTCTTCGGAGAAAAGCTGGGGACTTTCGAGCCTGGCGCTTTAAGATTAGCCTGCGTCCGATTAGCTAGTTGGTAGGGTAAAGGCCTACCAAGGCGACGATCAGTAGCTGGTCTGAGAGGATGACCAGCCACACTGGAACTGAGACACGGTCCAGACTCCTACGGGAGGCAGCAGTGGGGAATATTGGACAATGGGGGCAACCCTGATCCAGCAATGCCGCGTGTGTGAAGAAGGCCTGAGGGTTGTAAAGCACTTTCAGTGGGGAGGAGGGTTTCCCGGTTAAGAGCTAGGGGCATTGGACGTTACCCACAGAAGAAGCACCGGCTAACTCCGTGCCAGCAGCCCGCGGTAATACGGGAGGGTGCAAGCGTTAATCGGAATTACTGGGCCGTTAAAAGGTGCCTAAGGTGGTTTGGATAGTTATGTGTTAAATTCCCTGGCGCCTCCACCCTGGGCCAGGTCCATATAAAAACTGTTAAACTCCGAAGTATGGGCACAAGGTAATTGGAAATTCCGGTGGTACCGTGAAAATGCGCTTAGAGATCGGGAAGGGACCACCCCAGTGGGGAAGGCGGCTACCTGGCCTAATAACTGACATTGAGGCACGAAAAGCGTGGGGAGCAACCAGGATTAGATACCCTGGTAGTCCACGCTGTAAACGATGTCAACTAGCTGTGGTTATATGAATATAATTAGTGGCGAAGCTAACGCGATAAGTTGACCGCCTGGGGAGTACGGTCGCAAGATTAAAACTCAAAGGAATGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGATGCAACGCGAAGAACCTTACCTACCCTTGACATACAGTAAATCTTTCAGAGATGAGAGAGTGCCTTCGGGAATACTGATACAGGTGCTGCATGGCTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGTAACGAGCGCAACCCTTATCTCTAGTTGCCAGCGAGTAATGTCGGGAACTCTAAAGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAAGTCATCATGGCCCTTACGGGTAGGGCTACACACGTGCTACAATGGCCGATACAGAGGGGCGCGAAGGAGCGATCTGGAGCAAATCTTATAAAGTCGGTCGTAGTCCGGATTGGAGTCTGCAACTCGACTCCATGAAGTCGGAATCGCTAGTAATCGCGAATCAGCATGTCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCATGGGAGTGGGCTGCACCAGAAGTAGATAGTCTAACCGCAAGGGGGACGTTTACCACGGTGTGGTTCATGACTGGGGTGAAGTCGTAACAAGGTAGCCG")
s2 = DNA("TTTTCTTGGATTTGATTCTGGTCCAGAGTAAACGCTTGAGATATGTTGATACATGTTAGTTAAACGTGAATATTTGGTTTTTATGCCAACTTTATTTAAGTAGCGTATAGGTGAGTAATATGCAAGAATCCTACCTTTTAGTTTATGTAGCTCGTAAATTTATAAAAGATTTTTTCGCTAAAAGATGGGCTTGCACAAGATTAGGTTTTTGGTTTGCTAAAAACGTTCCAAGCCTAAGATCTTTAGCCGGCTTTCGTGAGTGACCGGCCACATAGGGACTGAGACAATGCCCTAGCTCCTTTTCTGGAGGCATCAGTACAAAGCATTGGACAATGAACGAAAGTTTGATCCAGTAATATCTCGTGAATGATGAAGGGTTTTTGCTCGTAAATTTCTTTTAGTTGAAAGAAAAAAGATATATTTCAACAGAAAAAATCCTGGCAAATCCTCGTGCCAGCAGCCGCGGTAATACGAGAAGGGTTAGCGTTACTCGAAATTATTGGGCGTAAAGTGCGTGAACAGCTGCTTTTTAAGCTATAGGCAGAAAAATCAAGGGTTAATCTTGTTTTTGTCATAGTTCTGATAAGCTTGAGTTTGGAAGAAGATAATAGAACATTTTATGGAGCGATGAAATGCTATGATATAAAAGAGAATACCAAAAGCGAAGGCAGTTATCTAGTACAAAACTGACGCCTATACGCGAAGGCTTAGGTAGCAAAAAGGATTAGGGACCCTTGTAGTCTAAGCTGTCAACGATGAACACTCGTTTTTGGATCACTTTTTTTCAGAAACTAAGCTAACGCGTTAAGTGTTTCGCCTGGGTACTACGGTCGCAAGACTAAAACTTAAAGAAATTGGCGGGAGTAAAAACAAGCAGTGGAGCGTGTGGTTTAATTCGATAGTACACGCAAATCTTACCATTACTTGACTCAAACATTGAAATGCACTATGTTTATGGTGTTGTTTAAGTATTATTTTACTTATAGATGTGCAGGCGCTGCATGGTTGTCGTCAGTTCGTGTCGTGAGATGTTTGGTTAATTCCCTTAACGAACGTAACCCTCAAAGCATATTCAAAACATTTTGTTTTTTTGTTAAACAGTCGGGGAAACCTGAATGTAGAGGGGTAGACGTCTAAATCTTTATGGCCCTTATGTATTTGGGCTACTCATGCGCTACAATGGGTGTATTCTACAAAAAGACGCAAAAACTCTTCAGTTTGAGCAAAACTTGAAAAGCACCCTCTAGTTCGGATTGAACTCTGGAACTCGAGTTCATAAAGTTGGAATTGCTAGTAATCGTGAGTTAGCGTATCGCGGTGAATCGAAAATTTACTTTGTACATACCGCCCGTCAAGTACTGAAAATTTGTATTGCAAGAAATTTTTGGAGAATTTACTTAACTCTTTTTTTTTTTAAGTTGGCTGTATCAGTCTTTTAAAAACTTTGAGTTAGGTTTTAAGCATCCGAGGGTAAAAGCAACATTTTTTATTGGTATTAAGTCGTAACAAGGTAGCCCTACGGG")


# We're inputting a pair of distantly related full-length 16S rRNA that are each known to represent the full gene sequences. For that reason, we want to penalize terminal gaps when we do global alignment.

# In[2]:


aln, _, _ = global_pairwise_align_nucleotide(s1, s2, penalize_terminal_gaps=True)


# We can now easily compute the fraction of positions that are identical in the resulting aligned sequences:

# In[3]:


seq1, seq2 = aln
seq1.match_frequency(seq2, relative=True)


# If we instead want to just know the count of positions that are the same, we can call this without ``relative=True``.

# In[4]:


seq1.match_frequency(seq2)