def test_permutted(self):
dm1 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
# this should not throw
pcoa(dm1, method="fsvd", number_of_dimensions=3, inplace=False)
# some operations, like permute, will change memory structure
# we want to test that this does not break pcoa
dm2 = dm1.permute()
# we just want to assure it does not throw
pcoa(dm2, method="fsvd", number_of_dimensions=3, inplace=False)
def test_fsvd_inplace(self):
dm1 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
dm2 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
expected_results = pcoa(dm1, method="eigh", number_of_dimensions=3,
inplace=True)
results = pcoa(dm2, method="fsvd", number_of_dimensions=3,
inplace=True)
assert_ordination_results_equal(results, expected_results,
ignore_directionality=True,
ignore_method_names=True)
def get_pcoa(args, dm1):
#from cogent.cluster.metric_scaling import PCoA
from skbio.stats.ordination import pcoa
PCoA_result = pcoa(dm1)
print (PCoA_result.samples())
#dt = np.dtype(float)
#print(type(PCoA_result))
a = np.array(PCoA_result)[0:,0:5] # capture only the first three vectors
#print a
json_array = {}
json_array["P1"] = a[:,2].tolist()[:-2] # [:-2] is to remove the last two which are not eigen vectors
json_array["P2"] = a[:,3].tolist()[:-2]
try:
json_array["P3"] = a[:,4].tolist()[:-2]
except IndexError:
sys.exit('IndexError - try selecting more data or deeper taxonomy')
json_array["names"] = a[:,1].tolist()[:-2]
#json['v2'] = [x[0] for x in np.array(PCoA_result[:,3])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
# sprint json_array
if args.function == 'pcoa_3d':
create_emperor_pc_file(args, json_array, PCoA_result)
return json_array
def fit(self, X, y=None):
"""
Parameters
----------
X : array-like
Feature table or distance matrix
y : None
ignored
Returns
-------
self
fitted pcoa
"""
X_to_ordinate = X
if self.metric != 'precomputed':
X_to_ordinate = cdist(
X_to_ordinate,
X_to_ordinate,
metric=self.metric,
)
self.ordination_ = pcoa(X_to_ordinate)
self.embedding_ = self.ordination_.samples
return self
def setUp(self):
# Crawford dataset for unweighted UniFrac
fp = get_data_path('PCoA_sample_data_3')
self.ordination = pcoa(DistanceMatrix.read(fp))
fp = get_data_path('PCoA_biplot_descriptors')
self.descriptors = pd.read_table(fp, index_col='Taxon').T
def test_compare_to_rcode():
windows, _ = ls.parse_vcf(vcf_file, "chr1", 95)
covmat, total_variance, eigenvals, eigenvecs = ls.cov_pca(windows[0].todense(), 10, 1)
results = np.loadtxt("lostruct-results/chr1.filtered.pca.csv",
delimiter=",",
skiprows=1)
totalandvalsR = results[0][0:11]
totalandvalsPy = np.concatenate(([total_variance], eigenvals)),
# Comes out as 0.9999921929150888
assert(np.corrcoef(totalandvalsR, totalandvalsPy)[0][1] >= 0.99999)
# Squared here, because signs are often opposite between the two analyses.
eigenvecsR = np.square(results[0][11:61])
eigenvecsPy = np.square(eigenvecs[0])
# Comes out as 0.9999921929150888
assert(np.corrcoef(eigenvecsR, eigenvecsPy)[0][1] >= 0.99999)
assert(covmat.shape == (50, 50))
mds_coords = np.loadtxt("lostruct-results/mds_coords.csv",
delimiter=",", skiprows=1, usecols=[2])
result = list()
for x in windows:
result.append(ls.eigen_windows(x, 10, 1))
result = np.vstack(result)
pc_dists = ls.get_pc_dists(result)
mds = pcoa(pc_dists)
# Comes out as 0.9971509982243156
assert(np.corrcoef(mds.samples['PC1'], mds_coords)[0][1] >= 0.995)
def setUp(self):
# Crawford dataset for unweighted UniFrac
fp = get_data_path('PCoA_sample_data_3')
self.ordination = pcoa(DistanceMatrix.read(fp))
fp = get_data_path('PCoA_biplot_descriptors')
self.descriptors = pd.read_table(fp, index_col='Taxon').T
def generate_aitchison_pcoa(self, df):
"""
Takes in count dataframe and generate pcoa matrix using aitchison distance matrix as input (aitchison distance is calculated in this function)
Parameters
------------
dataframe: pandas dataframe object
where
rows = samples
columns = OTU
and each datapoint is the either read count or relative abundance.
Returns
------------
pcoa.sample = pandas dataframe object
this stores the pcoa generated values to be visualised
dist_matrix = pandas dataframe object
this stores the distance scores used to generate the pcoa values.
"""
dist_matrix = self.aitchison_distance_matrix(df)
dm = DistanceMatrix(dist_matrix, dist_matrix.index)
pcoa = ordination.pcoa(dm)
return pcoa.samples, dist_matrix
def test_simple(self):
eigvals = [
0.51236726, 0.30071909, 0.26791207, 0.20898868, 0.19169895,
0.16054235, 0.15017696, 0.12245775, 0.0
]
proportion_explained = [
0.2675738328, 0.157044696, 0.1399118638, 0.1091402725,
0.1001110485, 0.0838401162, 0.0784269939, 0.0639511764, 0.0
]
sample_ids = [
'PC.636', 'PC.635', 'PC.356', 'PC.481', 'PC.354', 'PC.593',
'PC.355', 'PC.607', 'PC.634'
]
axis_labels = ['PC%d' % i for i in range(1, 10)]
expected_results = OrdinationResults(
short_method_name='PCoA',
long_method_name='Principal Coordinate Analysis',
eigvals=pd.Series(eigvals, index=axis_labels),
samples=pd.DataFrame(np.loadtxt(
get_data_path('exp_PCoAEigenResults_site')),
index=sample_ids,
columns=axis_labels),
proportion_explained=pd.Series(proportion_explained,
index=axis_labels))
dm = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
results = pcoa(dm)
assert_ordination_results_equal(results,
expected_results,
ignore_directionality=True)
def test_simple(self):
eigvals = [0.51236726, 0.30071909, 0.26791207, 0.20898868,
0.19169895, 0.16054235, 0.15017696, 0.12245775,
0.0]
proportion_explained = [0.2675738328, 0.157044696, 0.1399118638,
0.1091402725, 0.1001110485,
0.0838401162, 0.0784269939,
0.0639511764, 0.0]
sample_ids = ['PC.636', 'PC.635', 'PC.356', 'PC.481', 'PC.354',
'PC.593', 'PC.355', 'PC.607', 'PC.634']
axis_labels = ['PC%d' % i for i in range(1, 10)]
expected_results = OrdinationResults(
short_method_name='PCoA',
long_method_name='Principal Coordinate Analysis',
eigvals=pd.Series(eigvals, index=axis_labels),
samples=pd.DataFrame(
np.loadtxt(get_data_path('exp_PCoAEigenResults_site')),
index=sample_ids, columns=axis_labels),
proportion_explained=pd.Series(proportion_explained,
index=axis_labels))
dm = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
results = pcoa(dm)
assert_ordination_results_equal(results, expected_results,
ignore_directionality=True)
def dm_to_pcoa(dm, sample_md, category):
title = "Samples colored by %s." % category
pcoa_results = pcoa(dm)
_ = pcoa_results.plot(df=sample_md,
column=category,
axis_labels=['PC 1', 'PC 2', 'PC 3'],
title=title,
s=35)
def dm_to_pcoa(dm, sample_md, category):
title = "Samples colored by %s." % category
pcoa_results = pcoa(dm)
_ = pcoa_results.plot(df=sample_md,
column=category,
axis_labels=['PC 1', 'PC 2', 'PC 3'],
title=title,
s=35)
def on_update(category, metadata, metric):
dm = dms[metric]
filtered_dm, _ = filter_dm_and_map(dm, metadata)
pc = pcoa(filtered_dm)
pc.plot(df=metadata,
column=category,
axis_labels=['PC 1', 'PC 2', 'PC 3'],
s=35).set_size_inches(12, 9)
def on_update(category, metadata, metric):
dm = dms[metric]
filtered_dm, _ = filter_dm_and_map(dm, metadata)
pc = pcoa(filtered_dm)
pc.plot(df=metadata,
column=category,
axis_labels=['PC 1', 'PC 2', 'PC 3'],
s=35).set_size_inches(12, 9)
def diversity_analysis(wu_dm_list,bc_dm_list):
from skbio.stats.distance import mantel
#do the UniFrac and Bray-Curtis distances correlate?
r, p_value, n = mantel(wu_dm_list[0],bc_dm_list[0])
print("Mantel Correlation COEF=",r)
print("At significance of 0.05, the p-value for the correlation is = ",p_value)
#next perform principle coordinate analysis (PCoA) on the weighted UniFrac distance matrix:
from skbio.stats.ordination import pcoa
wu_pc = pcoa(wu_dm_list[0])
def __eapply__(self, experiment):
dm = experiment.data_df
pcoa_results = pcoa(dm)
pcoa_df = pcoa_results.samples
pcoa_df.index = dm.index #sample names
pcoa_df = pcoa_df.transpose()
pcoa_exp = experiment.with_data_df(pcoa_df)
pcoa_exp.metadata['pcoa'] = pcoa_results
return pcoa_exp
def create_emperor_pc_file(args, dist, ds_list):
#from cogent3.cluster.metric_scaling import PCoA
from skbio.stats.ordination import pcoa
PCoA_result = pcoa(dist)
PCoA_result.samples.index = ds_list
pcfile = os.path.join(args.basedir, 'tmp',args.prefix+'_pc.txt')
PCoA_result.write(pcfile)
return pcfile
def do_pcoa(infile):
samples, distmtx = parse_distmat(infile)
# coords, each row is an axis
distmtx = DistanceMatrix(distmtx, ids=samples)
ord_res = pcoa(distmtx)
coords = ord_res.samples
eigvals = ord_res.eigvals
pcnts = ord_res.proportion_explained
#Write results to output
ord_res.write(sys.stdout)
def create_emperor_pc_file(args, dist, ds_list):
#from cogent3.cluster.metric_scaling import PCoA
from skbio.stats.ordination import pcoa
PCoA_result = pcoa(dist)
PCoA_result.samples.index = ds_list
pcfile = os.path.join(args.basedir, args.prefix + '_pc.txt')
PCoA_result.write(pcfile)
try:
os.chmod(pcfile, 0o664)
except:
pass
return pcfile
def test_centroids_eq_groups(self):
exp = [[1.2886811963240687, 1.890538910062923, 1.490527658097728],
[2.17349240061718, 2.3192679626679946, 2.028338553903792]]
exp_stat, _ = f_oneway(*exp)
dm = pcoa(self.eq_mat)
dm = dm.samples
obs = _compute_groups(dm, 'centroid', self.grouping_eq)
self.assertAlmostEqual(obs, exp_stat, places=6)
obs_relab = _compute_groups(dm, 'centroid', self.grouping_eq_relab)
self.assertAlmostEqual(obs_relab, obs, places=6)
def test_centroids_mixedgroups(self):
exp = [[2.5847022428144935, 2.285624595858895,
1.7022431146340287],
[1.724817266046108, 1.724817266046108],
[2.4333280644972795, 2.389000390879655,
2.8547180589306036, 3.218568759338847]]
dm = pcoa(self.uneq_mat)
dm = dm.samples
exp_stat, _ = f_oneway(*exp)
obs_mixed = _compute_groups(dm, 'centroid', self.grouping_un_mixed)
self.assertAlmostEqual(exp_stat, obs_mixed, places=6)
def test_centroids_mixedgroups(self):
exp = [[2.5847022428144935, 2.285624595858895,
1.7022431146340287],
[1.724817266046108, 1.724817266046108],
[2.4333280644972795, 2.389000390879655,
2.8547180589306036, 3.218568759338847]]
dm = pcoa(self.uneq_mat)
dm = dm.samples
exp_stat, _ = f_oneway(*exp)
obs_mixed = _compute_groups(dm, 'centroid', self.grouping_un_mixed)
self.assertAlmostEqual(exp_stat, obs_mixed, places=6)
def test_centroids_eq_groups(self):
exp = [[1.2886811963240687, 1.890538910062923, 1.490527658097728],
[2.17349240061718, 2.3192679626679946, 2.028338553903792]]
exp_stat, _ = f_oneway(*exp)
dm = pcoa(self.eq_mat)
dm = dm.samples
obs = _compute_groups(dm, 'centroid', self.grouping_eq)
self.assertAlmostEqual(obs, exp_stat, places=6)
obs_relab = _compute_groups(dm, 'centroid', self.grouping_eq_relab)
self.assertAlmostEqual(obs_relab, obs, places=6)
def plot_pcoas(metric):
mpl.rcParams['figure.dpi'] = 100
mpl.rcParams['figure.figsize'] = 9, 6
df = pd.read_csv(glob.glob('diversity_core_metrics/' + ref_db + '/rpt_' + metric + '_dist/*/data/distance-matrix.tsv')[0],sep='\t',index_col=0)
sample_ids = df.index.values
dist = df.to_numpy()
dm = DistanceMatrix(dist, sample_ids)
pc = pcoa(dm)
var1 = str(round(pc.proportion_explained[0]*100, 2))
var2 = str(round(pc.proportion_explained[1]*100, 2))
var3 = str(round(pc.proportion_explained[2]*100, 2))
for i in m.columns:
ax = pc.plot(m, i, cmap='Accent', axis_labels=('PC1, '+var1+'%', 'PC2, '+var2+'%', 'PC3, '+var3+'%'), title= metric + " PCoA colored by " + i)
def beta_diversity_pcoa(biom_fp, method="braycurtis", permutations=99, dim=2,
col='method', colormap={'expected': 'red',
'rdp': 'seagreen',
'sortmerna': 'gray',
'uclust': 'blue',
'blast': 'purple'}):
'''From biom table, compute Bray-Curtis distance; generate PCoA plot;
and calculate adonis differences.
biom_fp: path
Path to biom.Table containing sample metadata.
method: str
skbio.Diversity method to use for ordination.
permutations: int
Number of permutations to perform for anosim tests.
dim: int
Number of dimensions to plot. Currently supports only 2-3 dimensions.
col: str
metadata name to use for distinguishing groups for anosim tests and
pcoa plots.
colormap: dict
map groups names (must be group names in col) to colors used for plots.
'''
dm, s_md = make_distance_matrix(biom_fp, method=method)
# pcoa
pc = pcoa(dm)
# anosim tests
results = anosim(dm, s_md, column=col, permutations=permutations)
print('R = ', results['test statistic'], '; P = ', results['p-value'])
if dim == 2:
# bokeh pcoa plots
pc123 = pc.samples.ix[:, ["PC1", "PC2", "PC3"]]
smd_merge = s_md.merge(pc123, left_index=True, right_index=True)
smd_merge['Color'] = [colormap[x] for x in smd_merge['method']]
title = smd_merge['reference'][0]
labels = ['PC {0} ({1:.2f})'.format(d + 1, pc.proportion_explained[d])
for d in range(0, 2)]
circle_plot_from_dataframe(smd_merge, "PC1", "PC2", title,
columns=["method", "sample_id", "params"],
color="Color", labels=labels)
else:
# skbio pcoa plots
pcoa_plot_skbio(pc, s_md, col='method')
return s_md, results, pc, dm
def pcoa(args, dist, ds_list):
#from cogent3.cluster.metric_scaling import PCoA
from skbio.stats.ordination import pcoa, OrdinationResults
PCoA_result = pcoa(dist)
#,index=['a','b','c','d','e','f','g','h','i','j','k','l','m','n']
# <class 'skbio.stats.ordination._base.OrdinationResults'>
sc_2 = PCoA_result
#print(dist)
#print(type(sc_2))
df2 = PCoA_result.samples
df2.index = ds_list
print(PCoA_result)
#dt = np.dtype(float)
# print('sc_2.proportion_explained')
# print(sc_2.proportion_explained)
# print('eigvals')
# print(sc_2.eigvals)
# print('species')
# print(sc_2.species)
# print('site')
# print(sc_2.site)
ordfile = os.path.join(args.outdir, args.prefix + '.pc')
sc_2.write(ordfile)
sys.exit()
# print('end pcoa result')
a = np.array(
PCoA_result) #[0:,0:5] # capture only the first three vectors
#print a
json_array = {}
json_array["P1"] = a[:, 2].tolist(
)[:-2] # [:-2] is to remove the last two which are not eigen vectors
json_array["P2"] = a[:, 3].tolist()[:-2]
try:
json_array["P3"] = a[:, 4].tolist()[:-2]
except IndexError:
sys.exit('IndexError - try selecting more data or deeper taxonomy')
json_array["names"] = a[:, 1].tolist()[:-2]
#json['v2'] = [x[0] for x in np.array(PCoA_result[:,3])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
# sprint json_array
if args.function == 'pcoa_3d':
create_emperor_pc_file(args, json_array, PCoA_result)
return json_array
def fit_transform(self, data):
# try:
from skbio.stats.ordination import pcoa
# except:
# sys.exit("PCOA is using the pcoa implemened at scikit-bio.")
data = self._check_data(data)
if self.metric.name != "precomputed":
data = squareform(pdist(data, metric=self.metric.name))
data = self.metric.fit_transform(data)
else:
data = self.metric.fit_transform(data)
projected_data = pcoa(data)
self.pcoa = projected_data
return self.pcoa.samples.values[:, self.components]
def pcoa(args, dist, ds_list):
#from cogent3.cluster.metric_scaling import PCoA
from skbio.stats.ordination import pcoa, OrdinationResults
PCoA_result = pcoa(dist)
#,index=['a','b','c','d','e','f','g','h','i','j','k','l','m','n']
# <class 'skbio.stats.ordination._base.OrdinationResults'>
sc_2 = PCoA_result
#print(dist)
#print(type(sc_2))
df2 = PCoA_result.samples
df2.index = ds_list
print(PCoA_result)
#dt = np.dtype(float)
# print('sc_2.proportion_explained')
# print(sc_2.proportion_explained)
# print('eigvals')
# print(sc_2.eigvals)
# print('species')
# print(sc_2.species)
# print('site')
# print(sc_2.site)
ordfile = os.path.join(args.outdir,args.prefix+'.pc')
sc_2.write(ordfile)
sys.exit()
# print('end pcoa result')
a = np.array(PCoA_result) #[0:,0:5] # capture only the first three vectors
#print a
json_array = {}
json_array["P1"] = a[:,2].tolist()[:-2] # [:-2] is to remove the last two which are not eigen vectors
json_array["P2"] = a[:,3].tolist()[:-2]
try:
json_array["P3"] = a[:,4].tolist()[:-2]
except IndexError:
sys.exit('IndexError - try selecting more data or deeper taxonomy')
json_array["names"] = a[:,1].tolist()[:-2]
#json['v2'] = [x[0] for x in np.array(PCoA_result[:,3])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
#json['v3'] = [x[0] for x in np.array(PCoA_result[:,4])[:-2]]
# sprint json_array
if args.function == 'pcoa_3d':
create_emperor_pc_file(args, json_array, PCoA_result)
return json_array
def plot_pcoa(bs_iter = 10000):
# get F stat and p value
df = pd.read_csv(mt.get_path() + '/data/mult_by_pop.txt', sep = '\t', index_col=0)
#mt.get_F_2(df,4,4)
df = df/df.sum(axis=1)[:,None]
df_bc = pairwise_distances(df, metric='braycurtis')
df_pcoa = pcoa(df_bc , number_of_dimensions=3)
ord_matrix = df_pcoa.samples
F = mt.get_F_2(ord_matrix, 4,4)
F_nulls = []
for i in range(bs_iter):
F_nulls.append(mt.get_F_2(ord_matrix.sample(frac=1), 4,4)[0])
p_value = len([F_null for F_null in F_nulls if F_null > F[0]]) / bs_iter
print("F = " + str(round(F[0], 4)))
print("p = " + str(round(p_value, 4)))
#fig = plt.figure()
fig, ax = plt.subplots(figsize=(6, 6))
# Scatterplot on main ax
ax.axhline(y=0, color='k', linestyle=':', alpha = 0.8, zorder=1)
ax.axvline(x=0, color='k', linestyle=':', alpha = 0.8, zorder=2)
ax.scatter(0, 0, marker = "o", edgecolors='none', c = 'darkgray', s = 120, zorder=3)
ax.scatter(ord_matrix.ix[0:4,0],ord_matrix.ix[0:4,1], marker = "o",
edgecolors='#244162', c = 'blue', alpha = 0.8, s = 120, zorder=4, label='Wildtype')
ax.scatter(ord_matrix.ix[4:,0],ord_matrix.ix[4:,1], marker = "o",
edgecolors='#244162', c = 'r', alpha = 0.8, s = 120, zorder=4, label='Minimal cell')
confidence_ellipse(ord_matrix.ix[0:4,0],ord_matrix.ix[0:4,1], ax,
n_std=2, edgecolor='blue', linestyle='--', lw=3)
confidence_ellipse(ord_matrix.ix[4:,0],ord_matrix.ix[4:,1], ax,
n_std=2, edgecolor='red', linestyle='--', lw=3)
#ax1.xlim([-0.7,0.7])
#ax1.set_ylim([-0.7,0.7])
ax.set_xlabel('PCo 1 (' + str(round(df_pcoa.proportion_explained[0],3)*100) + '%)' , fontsize = 14)
ax.set_ylabel('PCo 2 (' + str(round(df_pcoa.proportion_explained[1],3)*100) + '%)' , fontsize = 14)
plt.legend(loc="upper right")
fig_name = mt.get_path() + '/figures/pcoa.png'
fig.savefig(fig_name, bbox_inches = "tight", pad_inches = 0.4, dpi = 600)
plt.close()
def test_extensive(self):
eigvals = [
0.3984635, 0.36405689, 0.28804535, 0.27479983, 0.19165361, 0.0
]
proportion_explained = [
0.2626621381, 0.2399817314, 0.1898758748, 0.1811445992,
0.1263356565, 0.0
]
sample_ids = [str(i) for i in range(6)]
axis_labels = ['PC%d' % i for i in range(1, 7)]
samples = [
[-0.028597, 0.22903853, 0.07055272, 0.26163576, 0.28398669, 0.0],
[
0.37494056, 0.22334055, -0.20892914, 0.05057395, -0.18710366,
0.0
],
[
-0.33517593, -0.23855979, -0.3099887, 0.11521787, -0.05021553,
0.0
],
[0.25412394, -0.4123464, 0.23343642, 0.06403168, -0.00482608, 0.0],
[
-0.28256844, 0.18606911, 0.28875631, -0.06455635, -0.21141632,
0.0
],
[0.01727687, 0.012458, -0.07382761, -0.42690292, 0.1695749, 0.0]
]
expected_results = OrdinationResults(
short_method_name='PCoA',
long_method_name='Principal Coordinate Analysis',
eigvals=pd.Series(eigvals, index=axis_labels),
samples=pd.DataFrame(samples,
index=sample_ids,
columns=axis_labels),
proportion_explained=pd.Series(proportion_explained,
index=axis_labels))
data = np.loadtxt(get_data_path('PCoA_sample_data_2'))
# test passing a numpy.ndarray and a DistanceMatrix to pcoa
# gives same results
for dm in (data, DistanceMatrix(data)):
results = pcoa(dm)
assert_ordination_results_equal(results,
expected_results,
ignore_directionality=True)
def js_PCoA(distributions):
"""Dimension reduction via Jensen-Shannon Divergence & Principal Components
Parameters
----------
distributions : array-like, shape (`n_dists`, `k`)
Matrix of distributions probabilities.
Returns
-------
pcoa : array, shape (`n_dists`, 2)
"""
dist_matrix = DistanceMatrix(dist.squareform(dist.pdist(distributions.values, _jensen_shannon)))
if skbio_old:
data = PCoA(dist_matrix).scores()
return data.site[:,0:2]
else:
return pcoa(dist_matrix).samples.values[:, 0:2]
def js_PCoA(distributions):
"""Dimension reduction via Jensen-Shannon Divergence & Principal Components
Parameters
----------
distributions : array-like, shape (`n_dists`, `k`)
Matrix of distributions probabilities.
Returns
-------
pcoa : array, shape (`n_dists`, 2)
"""
dist_matrix = DistanceMatrix(dist.squareform(dist.pdist(distributions.values, _jensen_shannon)))
if skbio_old:
data = PCoA(dist_matrix).scores()
return data.site[:,0:2]
else:
return pcoa(dist_matrix).samples.values[:, 0:2]
def test_centroids_uneq_groups(self):
"""
the expected result here was calculated by hand
"""
exp = [[2.5847022428144935, 2.285624595858895,
1.7022431146340287],
[1.724817266046108, 1.724817266046108],
[2.4333280644972795, 2.389000390879655,
2.8547180589306036, 3.218568759338847]]
exp_stat, _ = f_oneway(*exp)
dm = pcoa(self.uneq_mat)
dm = dm.samples
obs = _compute_groups(dm, 'centroid', self.grouping_uneq)
self.assertAlmostEqual(obs, exp_stat, places=6)
obs_relab = _compute_groups(dm, 'centroid', self.grouping_uneq_relab)
self.assertAlmostEqual(obs, obs_relab, places=6)
def test_centroids_uneq_groups(self):
"""
the expected result here was calculated by hand
"""
exp = [[2.5847022428144935, 2.285624595858895,
1.7022431146340287],
[1.724817266046108, 1.724817266046108],
[2.4333280644972795, 2.389000390879655,
2.8547180589306036, 3.218568759338847]]
exp_stat, _ = f_oneway(*exp)
dm = pcoa(self.uneq_mat)
dm = dm.samples
obs = _compute_groups(dm, 'centroid', self.grouping_uneq)
self.assertAlmostEqual(obs, exp_stat, places=6)
obs_relab = _compute_groups(dm, 'centroid', self.grouping_uneq_relab)
self.assertAlmostEqual(obs, obs_relab, places=6)
def PCoA_total_from_matrix(distance_matrix, biom_file, metadata_file, plot=False):
sk_distance_matrix = DistanceMatrix(distance_matrix, BW.extract_samples(biom_file))
metadata = meta.extract_metadata(metadata_file)
pd_metadata = pd.DataFrame.from_dict(metadata, orient='index')
result = pcoa(sk_distance_matrix)
fig = result.plot(df=pd_metadata, column='body_site',
axis_labels=('PC 1 (' + str(round(result.proportion_explained.iloc[0]*100, 2)) + '%)', 'PC 2 (' + str(round(result.proportion_explained.iloc[1]*100, 2)) + '%)', 'PC 3 (' + str(round(result.proportion_explained.iloc[2]*100, 2)) + '%)'),
title='Samples colored by body site',
cmap='Set1', s=50)
fig.set_size_inches(18.5, 10.5)
if plot:
plt.show()
else:
return fig
def test_median_normal(self):
exp = pd.Series(index=self.exp_index,
data=['PERMDISP', 'F-value', 9, 2, 0.139475441876,
0.61, 99],
name='PERMDISP results')
np.random.seed(0)
obs = permdisp(self.unifrac_dm, self.unif_grouping, test='median',
permutations=99)
self.assert_series_equal(obs, exp)
np.random.seed(0)
po = pcoa(self.unifrac_dm)
obs2 = permdisp(po, self.unif_grouping, test='median',
permutations=99)
self.assert_series_equal(obs2, exp)
def test_median_fsvd(self):
exp = pd.Series(index=self.exp_index,
data=['PERMDISP', 'F-value', 9, 2, 0.04078077215673714,
0.8, 99],
name='PERMDISP results')
np.random.seed(0)
obs = permdisp(self.unifrac_dm, self.unif_grouping, test='median',
permutations=99,
method='fsvd', number_of_dimensions=3)
self.assert_series_equal(obs, exp)
np.random.seed(0)
po = pcoa(self.unifrac_dm, method='fsvd', number_of_dimensions=3)
obs = permdisp(po, self.unif_grouping, test='median',
permutations=99)
self.assert_series_equal(obs, exp)
def PCoA_group_from_matrix(distance_matrix, biom_file, groups, plot=False):
sk_distance_matrix = DistanceMatrix(distance_matrix, [str(i) for i in range(len(groups))])
metadata = {str(i): {'body_site': groups[i]} for i in range(len(groups))}
pd_metadata = pd.DataFrame.from_dict(metadata, orient='index')
result = pcoa(sk_distance_matrix)
fig = result.plot(df=pd_metadata, column='body_site',
axis_labels=('PC 1 (' + str(round(result.proportion_explained.iloc[0]*100, 2)) + '%)', 'PC 2 (' + str(round(result.proportion_explained.iloc[1]*100, 2)) + '%)', 'PC 3 (' + str(round(result.proportion_explained.iloc[2]*100, 2)) + '%)'),
title='Samples colored by body site',
cmap='Set1', s=50)
fig.set_size_inches(18.5, 10.5)
if plot:
plt.show()
else:
return fig
def PCoA_total_from_matrix_clustering(distance_matrix, biom_file, assignments, plot=False):
samples = BW.extract_samples(biom_file)
sk_distance_matrix = DistanceMatrix(distance_matrix, BW.extract_samples(biom_file))
metadata = {samples[i]: {'body_site': 'Group ' + str(assignments[i]+1)} for i in range(len(assignments))}
pd_metadata = pd.DataFrame.from_dict(metadata, orient='index')
result = pcoa(sk_distance_matrix)
fig = result.plot(df=pd_metadata, column='body_site',
axis_labels=('PC 1 (' + str(round(result.proportion_explained.iloc[0]*100, 2)) + '%)', 'PC 2 (' + str(round(result.proportion_explained.iloc[1]*100, 2)) + '%)', 'PC 3 (' + str(round(result.proportion_explained.iloc[2]*100, 2)) + '%)'),
title='Samples colored by body site',
cmap='Set1', s=50)
fig.set_size_inches(18.5, 10.5)
if plot:
plt.show()
else:
return fig
def fit(self, X, y=None):
"""
Parameters
----------
X : array-like
Feature table or distance matrix
y : None
ignored
Returns
-------
self
fitted pcoa
"""
if self.metric == 'precomputed':
self.embedding_ = pcoa(X).samples
else:
raise NotImplementedError()
return self
def test_extensive(self):
eigvals = [0.3984635, 0.36405689, 0.28804535, 0.27479983,
0.19165361, 0.0]
proportion_explained = [0.2626621381, 0.2399817314,
0.1898758748, 0.1811445992,
0.1263356565, 0.0]
sample_ids = [str(i) for i in range(6)]
axis_labels = ['PC%d' % i for i in range(1, 7)]
samples = [[-0.028597, 0.22903853, 0.07055272, 0.26163576,
0.28398669, 0.0],
[0.37494056, 0.22334055, -0.20892914, 0.05057395,
-0.18710366, 0.0],
[-0.33517593, -0.23855979, -0.3099887, 0.11521787,
-0.05021553, 0.0],
[0.25412394, -0.4123464, 0.23343642, 0.06403168,
-0.00482608, 0.0],
[-0.28256844, 0.18606911, 0.28875631, -0.06455635,
-0.21141632, 0.0],
[0.01727687, 0.012458, -0.07382761, -0.42690292,
0.1695749, 0.0]]
expected_results = OrdinationResults(
short_method_name='PCoA',
long_method_name='Principal Coordinate Analysis',
eigvals=pd.Series(eigvals, index=axis_labels),
samples=pd.DataFrame(samples, index=sample_ids,
columns=axis_labels),
proportion_explained=pd.Series(proportion_explained,
index=axis_labels))
data = np.loadtxt(get_data_path('PCoA_sample_data_2'))
# test passing a numpy.ndarray and a DistanceMatrix to pcoa
# gives same results
for dm in (data, DistanceMatrix(data)):
results = pcoa(dm)
assert_ordination_results_equal(results, expected_results,
ignore_directionality=True)
import pandas as pd
import matplotlib.pyplot as plt
import json
from sklearn.metrics import jaccard_similarity_score
from sklearn.metrics.pairwise import pairwise_distances
from skbio.stats.ordination import pcoa
# Compute Jaccard distances
# bcto_matrix = bcto_cover.as_matrix()
# bcto_distances = pairwise_distances(bcto_matrix,metric='jaccard')
# pcoa_of_distance = pcoa(bcto_distances)
# pcoa_of_distance.plot()
# plt.show()
# print pcoa_of_distance
# firm_matrix = firm_cover.as_matrix()
# firm_distances = pairwise_distances(firm_matrix,metric='jaccard')
# pcoa_of_distance = pcoa(firm_distances)
# pcoa_of_distance.plot()
# plt.show()
# print pcoa_of_distance
asf_bcto_firm_cover = pd.read_csv('../results/metagenome_coverage/asf_bcto_firm_mg_coverage.tsv',sep='\t')
asf_bcto_firm_matrix = asf_bcto_firm_cover.as_matrix()
asf_bcto_firm_distances = pairwise_distances(asf_bcto_firm_matrix,metric='jaccard')
pcoa_of_distance = pcoa(asf_bcto_firm_distances)
pcoa_of_distance.plot()
plt.show()
def test_centroids_null(self):
dm = pcoa(self.null_mat)
dm = dm.samples
obs_null = _compute_groups(dm, 'centroid', self.grouping_eq)
np.isnan(obs_null)
xls_file = "../data/Coral_ChemiFRAC_test.xlsx"
table = pd.read_excel(xls_file, sheetname=1, index_col=0).T
edges = pd.read_excel(xls_file, sheetname=0)
maxID = max([edges["CLUSTERID1"].max(), edges["CLUSTERID2"].max()]) + 1
spm = coo_matrix(
(edges["Cosine"].values, (edges["CLUSTERID1"].values, edges["CLUSTERID2"].values)), shape=(maxID, maxID)
)
coral_nwk = nx.from_scipy_sparse_matrix(spm)
meta_map = pd.read_table("../data/%s" % meta_file)
small_table = table
dm = pd.DataFrame(columns=meta_map.index, index=meta_map.index)
for i in range(len(meta_map.index)):
for j in range(i):
sampIDs = meta_map["#SampleID"].values
_x, _y = sampIDs[i], sampIDs[j]
x = small_table.loc[_x, :]
y = small_table.loc[_y, :]
dm.loc[_x, _y] = rig(coral_nwk, x, y)
dm.to_csv("../results/rig.txt", sep="\t")
dm = pd.read_csv("../results/rig.txt", index_col=0)
dm = dm.loc[meta_map["#SampleID"].values, meta_map["#SampleID"].values]
dm = dm.fillna(0)
dmpc = pcoa(dm + dm.T)
dmpc.samples.index = meta_map["#SampleID"].values
dmpc.write("../results/rig_pc.txt")
def test_fsvd(self):
dm1 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
dm2 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
dm3 = DistanceMatrix.read(get_data_path('PCoA_sample_data_3'))
# Test eigh vs. fsvd pcoa and inplace parameter
expected_results = pcoa(dm1, method="eigh", number_of_dimensions=3,
inplace=False)
results = pcoa(dm2, method="fsvd", number_of_dimensions=3,
inplace=False)
results_inplace = pcoa(dm2, method="fsvd", number_of_dimensions=3,
inplace=True)
assert_ordination_results_equal(results, expected_results,
ignore_directionality=True,
ignore_method_names=True)
assert_ordination_results_equal(results, results_inplace,
ignore_directionality=True,
ignore_method_names=True)
# Test number_of_dimensions edge cases
results2 = pcoa(dm3, method="fsvd", number_of_dimensions=0,
inplace=False)
expected_results2 = pcoa(dm3, method="fsvd",
number_of_dimensions=dm3.data.shape[0],
inplace=False)
assert_ordination_results_equal(results2, expected_results2,
ignore_directionality=True,
ignore_method_names=True)
with self.assertRaises(ValueError):
dim_too_large = dm1.data.shape[0] + 10
pcoa(dm2, method="fsvd", number_of_dimensions=dim_too_large)
with self.assertRaises(ValueError):
pcoa(dm2, method="fsvd", number_of_dimensions=-1)
with self.assertRaises(ValueError):
dim_too_large = dm1.data.shape[0] + 10
pcoa(dm2, method="eigh", number_of_dimensions=dim_too_large)
with self.assertRaises(ValueError):
pcoa(dm2, method="eigh", number_of_dimensions=-1)
dm_big = DistanceMatrix.read(get_data_path('PCoA_sample_data_12dim'))
with self.assertWarnsRegex(RuntimeWarning,
"no value for number_of_dimensions"):
pcoa(dm_big, method="fsvd", number_of_dimensions=0)
def plot_mds(
self,
rank="auto",
metric="braycurtis",
method="pcoa",
title=None,
xlabel=None,
ylabel=None,
color=None,
size=None,
tooltip=None,
return_chart=False,
label=None,
):
"""Plot beta diversity distance matrix using multidimensional scaling (MDS).
Parameters
----------
rank : {'auto', 'kingdom', 'phylum', 'class', 'order', 'family', 'genus', 'species'}, optional
Analysis will be restricted to abundances of taxa at the specified level.
metric : {'braycurtis', 'manhattan', 'jaccard', 'unifrac', 'unweighted_unifrac}, optional
Function to use when calculating the distance between two samples.
method : {'pcoa', 'smacof'}
Algorithm to use for ordination. PCoA uses eigenvalue decomposition and is not well
suited to non-euclidean distance functions. SMACOF is an iterative optimization strategy
that can be used as an alternative.
title : `string`, optional
Text label at the top of the plot.
xlabel : `string`, optional
Text label along the horizontal axis.
ylabel : `string`, optional
Text label along the vertical axis.
size : `string` or `tuple`, optional
A string or a tuple containing strings representing metadata fields. The size of points
in the resulting plot will change based on the metadata associated with each sample.
color : `string` or `tuple`, optional
A string or a tuple containing strings representing metadata fields. The color of points
in the resulting plot will change based on the metadata associated with each sample.
tooltip : `string` or `list`, optional
A string or list containing strings representing metadata fields. When a point in the
plot is hovered over, the value of the metadata associated with that sample will be
displayed in a modal.
label : `string` or `callable`, optional
A metadata field (or function) used to label each analysis. If passing a function, a
dict containing the metadata for each analysis is passed as the first and only
positional argument. The callable function must return a string.
Examples
--------
Scatter plot of weighted UniFrac distance between all our samples, using counts at the genus
level.
>>> plot_mds(rank='genus', metric='unifrac')
Notes
-----
**For `smacof`**: The values reported on the axis labels are Pearson's correlations between
the distances between points on each axis alone, and the corresponding distances in the
distance matrix calculated using the user-specified metric. These values are related to the
effectiveness of the MDS algorithm in placing points on the scatter plot in such a way that
they truly represent the calculated distances. They do not reflect how well the distance
metric captures similarities between the underlying data (in this case, an OTU table).
"""
if len(self._results) < 2:
raise OneCodexException("`plot_mds` requires 2 or more valid classification results.")
dists = self._compute_distance(rank, metric).to_data_frame()
# here we figure out what to put in the tooltips and get the appropriate data
if tooltip:
if not isinstance(tooltip, list):
tooltip = [tooltip]
else:
tooltip = []
tooltip.insert(0, "Label")
if color and color not in tooltip:
tooltip.insert(1, color)
if size and size not in tooltip:
tooltip.insert(2, size)
magic_metadata, magic_fields = self._metadata_fetch(tooltip, label=label)
if method == "smacof":
# adapted from https://scikit-learn.org/stable/auto_examples/manifold/plot_mds.html
x_field = "MDS1"
y_field = "MDS2"
seed = np.random.RandomState(seed=3)
mds = manifold.MDS(
max_iter=3000, eps=1e-12, random_state=seed, dissimilarity="precomputed", n_jobs=1
)
pos = mds.fit(dists).embedding_
plot_data = pd.DataFrame(pos, columns=[x_field, y_field], index=dists.index)
plot_data = plot_data.div(plot_data.abs().max(axis=0), axis=1) # normalize to [0,1]
# determine how much of the original distance is captured by each of the axes after MDS.
# this implementation of MDS does not use eigen decomposition and so there's no simple
# way of returning a 'percent of variance explained' value
r_squared = []
for axis in [0, 1]:
mds_dist = pos.copy()
mds_dist[::, axis] = 0
mds_dist = squareform(euclidean_distances(mds_dist).round(6))
r_squared.append(pearsonr(mds_dist, squareform(dists))[0])
# label the axes
x_extra_label = "r² = %.02f" % (r_squared[0],)
y_extra_label = "r² = %.02f" % (r_squared[1],)
elif method == "pcoa":
# suppress eigenvalue warning from skbio--not because it's an invalid warning, but
# because lots of folks in the field run pcoa on these distances functions, even if
# statistically inappropriate. perhaps this will change if we ever become more
# opinionated about the analyses that we allow our users to do (roo)
with warnings.catch_warnings():
warnings.simplefilter("ignore")
ord_result = ordination.pcoa(
dists.round(6)
) # round to avoid float precision errors
plot_data = ord_result.samples.iloc[:, [0, 1]] # get first two components
plot_data = plot_data.div(plot_data.abs().max(axis=0), axis=1) # normalize to [0,1]
plot_data.index = dists.index
x_field, y_field = plot_data.columns.tolist() # name of first two components
x_extra_label = "%0.02f%%" % (ord_result.proportion_explained[0] * 100,)
y_extra_label = "%0.02f%%" % (ord_result.proportion_explained[1] * 100,)
else:
raise OneCodexException("MDS method must be one of: smacof, pcoa")
# label the axes
if xlabel is None:
xlabel = "{} ({})".format(x_field, x_extra_label)
if ylabel is None:
ylabel = "{} ({})".format(y_field, y_extra_label)
plot_data = pd.concat([plot_data, magic_metadata], axis=1).reset_index()
alt_kwargs = dict(
x=alt.X(x_field, axis=alt.Axis(title=xlabel)),
y=alt.Y(y_field, axis=alt.Axis(title=ylabel)),
tooltip=[magic_fields[t] for t in tooltip],
href="url:N",
url="https://app.onecodex.com/classification/" + alt.datum.classification_id,
)
# only add these parameters if they are in use
if color:
alt_kwargs["color"] = magic_fields[color]
if size:
alt_kwargs["size"] = magic_fields[size]
chart = (
alt.Chart(plot_data)
.transform_calculate(url=alt_kwargs.pop("url"))
.mark_circle()
.encode(**alt_kwargs)
)
if title:
chart = chart.properties(title=title)
if return_chart:
return chart
else:
chart.interactive().display()
def test_invalid_input(self):
with npt.assert_raises(DissimilarityMatrixError):
pcoa([[1, 2], [3, 4]])
#svgfile = os.path.join('/Users/avoorhis/programming/jupyter/VAMPS_API',args.prefix+'_dendrogram.svg')
svgfile = os.path.join(args.outdir,args.prefix+'_dendrogram.svg')
print(os.getcwd())
#print svgfile
print('rendering0')
rooted_tree.render(svgfile, tree_style=ts) # writes file to tmp
if args.function == 'pcoa_3d':
#print('starting pcoa_3d')
from skbio import DistanceMatrix
dm = DistanceMatrix(dm1)
#print(dm1)
#print('end pcoa_3d')
pcoa_data = pcoa(args, dm, datasets)
#test_PCoA()
if args.function == 'pcoa_2d':
# if not args.metadata:
# print "ERROR: In PCoA and no metadata recieved"
# sys.exit()
pcoa_data = pcoa(args, dm3)
#print json.dumps(pcoa_data)
#metadata = json.loads( args.metadata.strip("'") )
pcoa_pdf(args, pcoa_data)
#print pcoa_data
def permdisp(distance_matrix, grouping, column=None, test='median',
permutations=999):
"""Test for Homogeneity of Multivariate Groups Disperisons using Marti
Anderson's PERMDISP2 procedure.
PERMDISP is a multivariate analogue of Levene's test for homogeneity of
multivariate variances. Distances are handled by reducing the
original distances to principal coordinates. PERMDISP calculates an
F-statistic to assess whether the dispersions between groups is significant
Parameters
----------
distance_matrix : DistanceMatrix
Distance matrix containing distances between objects (e.g., distances
between samples of microbial communities).
grouping : 1-D array_like or pandas.DataFrame
Vector indicating the assignment of objects to groups. For example,
these could be strings or integers denoting which group an object
belongs to. If `grouping` is 1-D ``array_like``, it must be the same
length and in the same order as the objects in `distance_matrix`. If
`grouping` is a ``DataFrame``, the column specified by `column` will be
used as the grouping vector. The ``DataFrame`` must be indexed by the
IDs in `distance_matrix` (i.e., the row labels must be distance matrix
IDs), but the order of IDs between `distance_matrix` and the
``DataFrame`` need not be the same. All IDs in the distance matrix must
be present in the ``DataFrame``. Extra IDs in the ``DataFrame`` are
allowed (they are ignored in the calculations).
column : str, optional
Column name to use as the grouping vector if `grouping` is a
``DataFrame``. Must be provided if `grouping` is a ``DataFrame``.
Cannot be provided if `grouping` is 1-D ``array_like``.
test : {'centroid', 'median'}
determines whether the analysis is done using centroid or spaitial
median.
permutations : int, optional
Number of permutations to use when assessing statistical
significance. Must be greater than or equal to zero. If zero,
statistical significance calculations will be skipped and the p-value
will be ``np.nan``.
Returns
-------
pandas.Series
Results of the statistical test, including ``test statistic`` and
``p-value``.
Raises
------
TypeError
If, when using the spatial median test, the pcoa ordination is not of
type np.float32 or np.float64, the spatial median function will fail
and the centroid test should be used instead
ValueError
If the test is not centroid or median.
TypeError
If the distance matrix is not an instance of a
``skbio.DistanceMatrix``.
ValueError
If there is only one group
ValueError
If a list and a column name are both provided
ValueError
If a list is provided for `grouping` and it's length does not match
the number of ids in distance_matrix
ValueError
If all of the values in the grouping vector are unique
KeyError
If there are ids in grouping that are not in distance_matrix
See Also
--------
permanova
anosim
Notes
-----
The significance of the results from this function will be the same as the
results found in vegan's betadisper, however due to floating point
variability the F-statistic results may vary slightly.
See [1]_ for the original method reference, as well as
``vegan::betadisper``, available in R's vegan package [2]_.
References
----------
.. [1] Anderson, Marti J. "Distance-Based Tests for Homogeneity of
Multivariate Dispersions." Biometrics 62 (2006):245-253
.. [2] http://cran.r-project.org/web/packages/vegan/index.html
Examples
--------
Load a 6x6 distance matrix and grouping vector denoting 2 groups of
objects:
>>> from skbio import DistanceMatrix
>>> dm = DistanceMatrix([[0, 0.5, 0.75, 1, 0.66, 0.33],
... [0.5, 0, 0.25, 0.33, 0.77, 0.61],
... [0.75, 0.25, 0, 0.1, 0.44, 0.55],
... [1, 0.33, 0.1, 0, 0.75, 0.88],
... [0.66, 0.77, 0.44, 0.75, 0, 0.77],
... [0.33, 0.61, 0.55, 0.88, 0.77, 0]],
... ['s1', 's2', 's3', 's4', 's5', 's6'])
>>> grouping = ['G1', 'G1', 'G1', 'G2', 'G2', 'G2']
Run PERMDISP using 99 permutations to caluculate the p-value:
>>> from skbio.stats.distance import permdisp
>>> import numpy as np
>>> #make output deterministic, should not be included during normal use
>>> np.random.seed(0)
>>> permdisp(dm, grouping, permutations=99)
method name PERMDISP
test statistic name F-value
sample size 6
number of groups 2
test statistic 1.03296
p-value 0.35
number of permutations 99
Name: PERMDISP results, dtype: object
The return value is a ``pandas.Series`` object containing the results of
the statistical test.
To suppress calculation of the p-value and only obtain the F statistic,
specify zero permutations:
>>> permdisp(dm, grouping, permutations=0)
method name PERMDISP
test statistic name F-value
sample size 6
number of groups 2
test statistic 1.03296
p-value NaN
number of permutations 0
Name: PERMDISP results, dtype: object
PERMDISP computes variances based on two types of tests, using either
centroids or spatial medians, also commonly referred to as a geometric
median. The spatial median is thought to yield a more robust test
statistic, and this test is used by default. Spatial medians are computed
using an iterative algorithm to find the optimally minimum point from all
other points in a group while centroids are computed using a deterministic
formula. As such the two different tests yeild slightly different F
statistics.
>>> np.random.seed(0)
>>> permdisp(dm, grouping, test='centroid', permutations=6)
method name PERMDISP
test statistic name F-value
sample size 6
number of groups 2
test statistic 3.67082
p-value 0.428571
number of permutations 6
Name: PERMDISP results, dtype: object
You can also provide a ``pandas.DataFrame`` and a column denoting the
grouping instead of a grouping vector. The following DataFrame's
Grouping column specifies the same grouping as the vector we used in the
previous examples.:
>>> import pandas as pd
>>> df = pd.DataFrame.from_dict(
... {'Grouping': {'s1': 'G1', 's2': 'G1', 's3': 'G1', 's4': 'G2',
... 's5': 'G2', 's6': 'G2'}})
>>> permdisp(dm, df, 'Grouping', permutations=6, test='centroid')
method name PERMDISP
test statistic name F-value
sample size 6
number of groups 2
test statistic 3.67082
p-value 0.428571
number of permutations 6
Name: PERMDISP results, dtype: object
Note that when providing a ``DataFrame``, the ordering of rows and/or
columns does not affect the grouping vector that is extracted. The
``DataFrame`` must be indexed by the distance matrix IDs (i.e., the row
labels must be distance matrix IDs).
If IDs (rows) are present in the ``DataFrame`` but not in the distance
matrix, they are ignored. The previous example's ``s7`` ID illustrates this
behavior: note that even though the ``DataFrame`` had 7 objects, only 6
were used in the test (see the "Sample size" row in the results above to
confirm this). Thus, the ``DataFrame`` can be a superset of the distance
matrix IDs. Note that the reverse is not true: IDs in the distance matrix
*must* be present in the ``DataFrame`` or an error will be raised.
PERMDISP should be used to determine whether the dispersions between the
groups in your distance matrix are significantly separated.
A non-significant test result indicates that group dispersions are similar
to each other. PERMANOVA or ANOSIM should then be used in conjunction to
determine whether clustering within groups is significant.
"""
if test not in ['centroid', 'median']:
raise ValueError('Test must be centroid or median')
ordination = pcoa(distance_matrix)
samples = ordination.samples
sample_size, num_groups, grouping, tri_idxs, distances = _preprocess_input(
distance_matrix, grouping, column)
test_stat_function = partial(_compute_groups, samples, test)
stat, p_value = _run_monte_carlo_stats(test_stat_function, grouping,
permutations)
return _build_results('PERMDISP', 'F-value', sample_size, num_groups,
stat, p_value, permutations)
index=samples,
columns=samples)
graph_dm.to_csv('../results/aitchison.txt', '\t')
# Read in graph_dm
graph_dm = pd.read_csv('../results/unconnected_aitchison.txt',
sep='\t', index_col=0)
# table = pd.read_table('../data/skinmap_chemiFrac_test.txt',
# sep='\t', index_col=0)
graph_dm.index = table.columns
graph_dm.columns = table.columns
# _dm = pw_distances('braycurtis', table.values, table.index.values)
# _dm.write('../results/braycurtis.txt')
_dm = DistanceMatrix(graph_dm.values + graph_dm.values.T)
_dm.ids = graph_dm.index
pcoa_v = pcoa(_dm)
fig = plt.figure(3)
plt.plot(pcoa_v.samples['PC1'],
pcoa_v.samples['PC2'], 'ob')
# plt.plot(pcoa_v.eigvecs[not_stressed, 0],
# pcoa_v.eigvecs[not_stressed, 1],
# 'o', c='#FFFFFF', label='Before stress')
# plt.plot(pcoa_v.eigvecs[stressed, 0],
# pcoa_v.eigvecs[stressed, 1],
# 'o', c='#999999', label='After stress')
# plt.legend(loc=3)
#plt.title('Weighted Aitchison on Coral data')
#fig.savefig('../results/coral_chemifrac.png')
pcoa_v.write('../results/coral_unconnected_aitchison_pcoa.txt')
