def test_codons(self):
"""PositionalBaseUsage codons should give expected codon freqs"""
#one of each base should give freqs if 1/64 for everything
orig = CodonUsage('UUUCCCAAAGGG')
b = orig.positionalBases()
final = b.codons()
self.assertEqual(len(final), 64)
for i in final:
self.assertFloatEqual(final[i], 1.0/64)
#two bases at each position should give correct freqs
orig = CodonUsage('UCGAGUUCGUCG')
final = orig.positionalBases().codons()
exp = {
'UCG': 0.75 * 0.75 * 0.75,
'UCU': 0.75 * 0.75 * 0.25,
'UGG': 0.75 * 0.25 * 0.75,
'UGU': 0.75 * 0.25 * 0.25,
'ACG': 0.25 * 0.75 * 0.75,
'ACU': 0.25 * 0.75 * 0.25,
'AGG': 0.25 * 0.25 * 0.75,
'AGU': 0.25 * 0.25 * 0.25,
}
for f in final:
if f in exp:
self.assertFloatEqual(final[f], exp[f])
else:
self.assertEqual(final[f], 0)
def test_aminoAcids(self):
"""PositionalBaseUsage aminoAcids should return correct amino acids"""
#check hand-calculated values on a particular sequence
orig = CodonUsage('UCGAGUUCGUCG')
final = orig.positionalBases().aminoAcids()
exp = {
'S': 0.75 * 0.75 * 0.75 + 0.75 * 0.75 * 0.25 + 0.25*0.25*0.25,
'W': 0.75 * 0.25 * 0.75,
'C': 0.75 * 0.25 * 0.25,
'T': 0.25 * 0.75 * 0.75 + 0.25 * 0.75 * 0.25,
'R': 0.25 * 0.25 * 0.75,
}
for f in final:
if f in exp:
self.assertFloatEqual(final[f], exp[f])
else:
self.assertEqual(final[f], 0)
#test for unbiased freqs on a couple of different genetic codes
orig = CodonUsage('UUUCCCAAAGGG')
final = orig.positionalBases().aminoAcids()
SGC = GeneticCodes[1]
for aa in final:
self.assertEqual(final[aa], len(SGC[aa])/64.0)
mt = GeneticCodes[2]
final_mt = orig.positionalBases().aminoAcids(mt)
self.assertNotEqual(final, final_mt)
for aa in final_mt:
self.assertEqual(final_mt[aa], len(mt[aa])/64.0)
def test_positionalBases(self):
"""CodonUsage bases should count bases at each position correctly"""
freqs = {'UUC':5, 'AUA':10, 'AUG':10, 'CGC':3, 'AGG':2, 'XYZ':8,
'UAA':2, 'UGA':1}
u = CodonUsage(freqs)
b = u.positionalBases()
assert isinstance(b, PositionalBaseUsage)
first, second, third = b
self.assertEqual(first, BaseUsage({'U':8,'C':3,'A':22,'X':8}))
self.assertEqual(second, BaseUsage({'U':25,'C':0,'A':2,'G':6,'Y':8}))
self.assertEqual(third, BaseUsage({'C':8,'A':13,'G':12,'Z':8}))
#check that it also works when we purge
p = u.positionalBases(purge_unwanted=True)
first, second, third = p
self.assertEqual(first, BaseUsage({'U':5,'C':3,'A':2}))
self.assertEqual(second, BaseUsage({'U':5,'G':5}))
self.assertEqual(third, BaseUsage({'C':8,'G':2}))
#check that it also works with a different genetic code, and,
#incidentally, that the purging didn't affect the original object
u.GeneticCode = GeneticCodes[2] #mt code: different stop codons
p = u.positionalBases(purge_unwanted=True)
first, second, third = p
self.assertEqual(first, BaseUsage({'U':6,'C':3,'A':20}))
self.assertEqual(second, BaseUsage({'U':25,'G':4}))
self.assertEqual(third, BaseUsage({'C':8,'A':11,'G':10}))
def test_rscu(self):
"""CodonUsage rscu should calculate synonymous usage correctly"""
c = CodonUsage({'UUU':3,'UUC':1,'ACA':1})
c.rscu()
self.assertEqual(c['UUU'], 0.75)
self.assertEqual(c['UUC'], 0.25)
self.assertEqual(c['ACA'], 1)
self.assertEqual(c['GGG'], 0)
def test_bases(self):
"""CodonUsage bases should count bases correctly"""
u = CodonUsage('UUUCCCUAGCCCGGGAA')
b = u.bases()
self.assertEqual(b, BaseUsage('UUUCCCUAGCCCGGGAA'))
#purge_unwanted should get rid of bad codons
b = u.bases(purge_unwanted=True)
self.assertEqual(b, BaseUsage('UUUCCCCCCGGG'))
def test_pr2bias(self):
"""CodonUsage pr2bias should give correct ratios."""
c = EqualBases.codons()
b = c.pr2bias('UU')
self.assertEqual(len(b), 6)
self.assertEqual(b, tuple([.5]*6))
c = CodonUsage()
c['ACU'] = 10
c['ACC'] = 5
c['ACA'] = 15
c['ACG'] = 20
self.assertEqual(c.pr2bias('AC'), (20/25,15/25,20/35,5/15,20/30,5/20))
def test_aminoAcids(self):
"""CodonUsage aminoAcids should correctly count amino acids"""
freqs = {'UUC':5, 'AUA':10, 'AUG':10, 'CGC':3, 'AGG':2, 'XYZ':8,
'UAA':2, 'UGA':1}
u = CodonUsage(freqs, "test")
self.assertEqual(u.Info, 'test')
for key, val in u.items():
if key in freqs:
self.assertEqual(val, freqs[key])
else:
self.assertEqual(val, 0)
aa = u.aminoAcids()
self.assertEqual(aa,
AminoAcidUsage({'F':5,'I':10,'M':10,'R':5,'*':3,'X':8}))
#check that it works with a different genetic code
u.GeneticCode = GeneticCodes['2']
aa = u.aminoAcids()
self.assertEqual(aa,
AminoAcidUsage({'F':5,'I':0,'M':20,'R':3,'*':4,'W':1,'X':8}))
#check that it works if a genetic code is supplied explicitly
u.GeneticCode = GeneticCodes[1]
aa = u.aminoAcids()
self.assertEqual(aa,
AminoAcidUsage({'F':5,'I':10,'M':10,'R':5,'*':3,'X':8}))
aa_2 = u.aminoAcids(2)
self.assertEqual(aa_2,
AminoAcidUsage({'F':5,'I':0,'M':20,'R':3,'*':4,'W':1,'X':8}))
#check that we held onto the info object through the above
self.assertEqual(aa_2.Info, 'test')
def test_aminoAcids(self):
"""BaseUsage aminoAcids should give the same results as the codons"""
known_data = {
'AAA' : .6 * .6 * .6,
'AAU' : .6 * .6 * .4,
'AUA' : .6 * .4 * .6,
'AUU' : .6 * .4 * .4,
'UAA' : .4 * .6 * .6,
'UAU' : .4 * .6 * .4,
'UUA' : .4 * .4 * .6,
'UUU' : .4 * .4 * .4,
}
known = CodonUsage(known_data)
b = BaseUsage({'a':3, 'T':2, 'X':1})
self.assertEqual(b.aminoAcids(), known.aminoAcids())
#check that the genetic code is passed through correctly
all_g = GeneticCode('G'*64)
self.assertEqual(b.aminoAcids(all_g), AminoAcidUsage({'G':1}))
def test_fingerprint(self):
"""CodonUsage fingerprint should give correct ratios."""
c = EqualBases.codons()
f = c.fingerprint()
self.assertEqual(len(f), 9)
self.assertEqual(f, \
[[.5,.5,.125] for i in range(8)] + [[.5,.5,1]])
#should be able to omit mean...
f = c.fingerprint(include_mean=False)
self.assertEqual(f, [[.5,.5,.125] for i in range(8)])
#...or use all doublets
f = c.fingerprint(include_mean=False, which_blocks='all')
self.assertEqual(len(f), 16)
#...or do just the non-quartet ones
f = c.fingerprint(include_mean=False, which_blocks='split')
self.assertEqual(len(f), 6)
#check that it doesn't fail on an empty codon usage
c = CodonUsage('')
f = c.fingerprint()
self.assertEqual(f[0], [0.5, 0.5, 0])
def test_codons(self):
"""AminoAcidUsage codons should return most likely codon freqs"""
a = AminoAcidUsage('GGG')
c = CodonUsage('GGUGGCGGAGGG')
c.normalize()
self.assertEqual(a.codons(), c)
a = AminoAcidUsage('D')
c = CodonUsage('GAUGAC')
c.normalize()
self.assertEqual(a.codons(), c)
a = AminoAcidUsage('GDDFMM')
c = CodonUsage('GGUGGCGGAGGG'+'GAUGAC'*4+'UUUUUC'*2+'AUG'*8)
c.normalize()
self.assertEqual(a.codons(), c)
a = AminoAcidUsage('II*')
c = CodonUsage('AUUAUCAUA'*2+'UAAUAGUGA')
c.normalize()
self.assertEqual(a.codons(), c)
#check that it works with a nonstandard code
code = GeneticCode('A'*4+'C'*28+'G'*32)
a = AminoAcidUsage('AAA')
c = CodonUsage('UUUUUCUUAUUG')
c.normalize()
self.assertEqual(a.codons(code), c)
#check that it works with unequal codon frequencies
unequal = CodonUsage({'GGU':5,'GGC':2,'GGA':2,'GGG':1,'UUU':3,'UUC':1})
a = AminoAcidUsage('GFFF')
exp = {
'GGU':0.5*0.25,
'GGC':0.2*0.25,
'GGA':0.2*0.25,
'GGG':0.1*0.25,
'UUU':0.75*0.75,
'UUC':0.25*0.75
}
obs = a.codons(codon_usage=unequal)
for codon, freq in obs.items():
self.assertFloatEqual(freq, exp.get(codon, 0))
def test_codons(self):
"""CodonUsage codons should return same object"""
u = CodonUsage('abc')
c = u.codons()
assert u is c
def test_init_string(self):
"""CodonUsage should count codons in string"""
u = CodonUsage('UUUCCCUUUUUUGA')
self.assertEqual(u, CodonUsage({'UUU':3, 'CCC':1, 'GA':1}))
u.normalize()
self.assertEqual(u, CodonUsage({'UUU':0.75, 'CCC':0.25}))