In [1]:
plt.rcdefaults()
# Typeface sizes
from matplotlib import rcParams
rcParams['axes.labelsize'] = 9
rcParams['xtick.labelsize'] = 9
rcParams['ytick.labelsize'] = 9
rcParams['legend.fontsize'] = 9
#rcParams['font.family'] = 'serif'
#rcParams['font.serif'] = ['Computer Modern Roman']
#rcParams['text.usetex'] = True

# Optimal figure size
WIDTH = 350.0  # the number latex spits out
FACTOR = 0.90  # the fraction of the width you'd like the figure to occupy
fig_width_pt  = WIDTH * FACTOR

inches_per_pt = 1.0 / 72.27
golden_ratio  = (np.sqrt(5) - 1.0) / 2.0  # because it looks good

fig_width_in  = fig_width_pt * inches_per_pt  # figure width in inches
fig_height_in = fig_width_in * golden_ratio   # figure height in inches
fig_dims      = [fig_width_in, fig_height_in] # fig dims as a list

rcParams['figure.figsize'] = fig_dims

In [2]:
%matplotlib inline

In [3]:
import pandas as pd
import matplotlib.pyplot as plt
pd.set_option('display.mpl_style', 'default')
import statsmodels.api as sm
import itertools

First, let's load the results from the small model of polled included in the default settings. This involves loading four animal files (live cows, dead cows, live bulls, and dead bulls). We will load them and merge them into a single data frame.


In [4]:
# We have 10 relicates for each simulation
for sim in xrange(1,11):
    # Load the individual history files
    lc = pd.read_csv('horich/%s/cows_history_pryce_holstein_20.txt'%sim, sep='\t')
    dc = pd.read_csv('horich/%s/dead_cows_history_pryce_holstein_20.txt'%sim, sep='\t')
    lb = pd.read_csv('horich/%s/bulls_history_pryce_holstein_20.txt'%sim, sep='\t')
    db = pd.read_csv('horich/%s/dead_bulls_history_pryce_holstein_20.txt'%sim, sep='\t')
    inbreeding = pd.read_csv('horich/%s/pedigree_20.txt.solinb'%sim, delim_whitespace=True,
                             skipinitialspace=True, names=['animal','inbreeding'])
    # Stack the individual animal datasets
    allan = lc.append(dc.append(lb.append(db)))
    # Merge in the coefficients of inbreeding (Pandas defaults to an inner join)
    all_animals = pd.merge(allan, inbreeding, on='animal')
    all_animals['rep'] = sim
    if sim == 1:
        all_replicates = all_animals
    else:
        all_replicates = pd.concat([all_replicates, all_animals])
# Print first few lines of dataframe
#all_animals.head()

In [5]:
# Now load the Pryce+recessives data so that we can compare EBV.
# We have 10 relicates for each simulation
for sim in xrange(1,11):
    # Load the individual history files
    lc = pd.read_csv('horich/%s/cows_history_pryce_r_holstein_20.txt'%sim, sep='\t')
    dc = pd.read_csv('horich/%s/dead_cows_history_pryce_r_holstein_20.txt'%sim, sep='\t')
    lb = pd.read_csv('horich/%s/bulls_history_pryce_r_holstein_20.txt'%sim, sep='\t')
    db = pd.read_csv('horich/%s/dead_bulls_history_pryce_r_holstein_20.txt'%sim, sep='\t')
    inbreeding = pd.read_csv('horich/%s/pedigree_20.txt.solinb'%sim, delim_whitespace=True,
                             skipinitialspace=True, names=['animal','inbreeding'])
    # Stack the individual animal datasets
    allan_r = lc.append(dc.append(lb.append(db)))
    # Merge in the coefficients of inbreeding (Pandas defaults to an inner join)
    all_animals_r = pd.merge(allan_r, inbreeding, on='animal')
    all_animals_r['rep'] = sim
    if sim == 1:
        all_replicates_r = all_animals_r
    else:
        all_replicates_r = pd.concat([all_replicates_r, all_animals_r])
# Print first few lines of dataframe
#all_animals.head()

In [6]:
all_replicates['rep'].value_counts()


Out[6]:
7     1794493
3     1794216
8     1794088
5     1794062
2     1794000
10    1793922
1     1793635
4     1793611
6     1793506
9     1793367
dtype: int64

In [7]:
# N = culled to maintain herd size
# A = culled for age
# R = culled because of lethal disorder
all_animals['cause'].value_counts()


Out[7]:
N    1600114
A     108119
R      20063
dtype: int64

How many males and females are in the dataset?


In [8]:
all_animals['sex'].value_counts()


Out[8]:
F    915917
M    878005
dtype: int64

If we want to plot the average TBV by sex for each generation we first need to construct a dataframe that has the average (mean) TBV for each group-sex combination.


In [9]:
grouped = all_animals.groupby(['sex','born']).mean()
#grouped
# Bulls and cows don't necessarily have identical sets of
# birth generations for founders since those values are
# randomly generated and bulls live longer than cows. In
# order to get the plots to work correctly, we need to
# reindex the aggregated dataframe.
full_index = []
for x in ['F','M']:
    for g in all_animals['born'].unique():
        full_index.append((x,g))
grouped = grouped.reindex(full_index).reset_index()
grouped = grouped.add_suffix('').reset_index()
grouped = grouped.sort(['level_0','level_1'])
#grouped

Now group the data for the Pryce+recessives scenario


In [10]:
grouped_r = all_animals_r.groupby(['sex','born']).mean()
full_index = []
for x in ['F','M']:
    for g in all_animals['born'].unique():
        full_index.append((x,g))
grouped_r = grouped_r.reindex(full_index).reset_index()
grouped_r = grouped_r.add_suffix('').reset_index()
grouped_r = grouped_r.sort(['level_0','level_1'])

In [11]:
print 'Average TBV by generation of birth and animal sex for the Pryce scenario'
all_animals.groupby(['sex','born']).mean()['TBV']


Average TBV by generation of birth and animal sex for the Pryce scenario
Out[11]:
sex  born
F    -4         1.981904
     -3        -3.286993
     -2         1.132599
     -1         4.849215
      0         0.073760
      1       160.733673
      2       356.591892
      3       557.959887
      4       764.514750
      5       964.163170
      6      1184.182801
      7      1383.500381
      8      1592.592470
      9      1821.454288
      10     2039.612547
      11     2235.442731
      12     2458.486540
      13     2684.994537
      14     2893.088506
      15     3116.683987
      16     3333.915275
      17     3566.829997
      18     3787.139847
      19     4020.124602
      20     4219.076812
M    -9       295.726948
     -8       330.456543
     -7       317.007963
     -6       359.398618
     -5       276.640821
     -4       326.545168
     -3       289.158601
     -2       245.484798
     -1       315.941260
      0       334.633022
      1       162.079410
      2       354.316139
      3       555.348076
      4       765.427147
      5       964.791211
      6      1184.845278
      7      1383.634319
      8      1592.199164
      9      1820.240815
      10     2039.948707
      11     2231.341922
      12     2457.766082
      13     2683.989115
      14     2890.332609
      15     3114.279118
      16     3331.663006
      17     3566.910968
      18     3790.633856
      19     4023.110625
      20     4260.955779
Name: TBV, Length: 55, dtype: float64

In [12]:
print 'Average TBV by generation of birth and animal sex for the Pryce+recessives scenario'
all_animals_r.groupby(['sex','born']).mean()['TBV']


Average TBV by generation of birth and animal sex for the Pryce+recessives scenario
Out[12]:
sex  born
F    -4         2.868579
     -3         1.962531
     -2        -1.434141
     -1         1.391701
      0        -0.058889
      1       161.970513
      2       380.937258
      3       559.666411
      4       773.913162
      5       981.597991
      6      1201.873282
      7      1406.635542
      8      1624.213080
      9      1826.024309
      10     2063.909905
      11     2283.189497
      12     2489.271711
      13     2707.542932
      14     2917.685472
      15     3147.118278
      16     3396.292539
      17     3606.513588
      18     3846.418065
      19     4044.751757
M    -9       281.948131
     -8       282.807044
     -7       275.088709
     -6       382.380453
     -5       321.897524
     -4       270.965344
     -3       301.715914
     -2       344.029399
     -1       287.698960
      0       330.621040
      1       164.187608
      2       377.345832
      3       561.043731
      4       773.412615
      5       985.922613
      6      1197.958844
      7      1402.766933
      8      1624.535893
      9      1829.276710
      10     2062.894605
      11     2285.662203
      12     2490.735055
      13     2710.309985
      14     2915.336141
      15     3149.884895
      16     3393.639226
      17     3606.078111
      18     3844.043750
      19     4042.630207
Name: TBV, Length: 53, dtype: float64

In [13]:
fig = plt.figure(figsize=fig_dims, dpi=300, facecolor='white')

# Set nicer limits
xmin ,xmax = 0, 30
ymin, ymax = 0, 0.25

ax = fig.add_subplot(1, 1, 1)
ax.set_xlabel('Generation')
ax.set_ylabel('True Breeding Value')
ax.plot(all_animals.groupby(['born']).mean()['TBV'], label='Pryce', linewidth=2)
ax.plot(all_animals_r.groupby(['born']).mean()['TBV'], label='Pryce+recessives', linewidth=2)
ax.legend(loc='best')

# Deal with ticks marks and labels
x_tick_locs = [t for t in xrange(0, 31, 5)]
x_tick_labels = [t for t in xrange(-10, 21, 5)]
xticks(x_tick_locs, x_tick_labels)

# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

# Plot and save
fig.tight_layout(pad=0.1)  # Make the figure use all available whitespace
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-average-tbv-by-gen-pryce-rec.png', dpi=300)


Looking at the plot below, it looks as though I may need to bump the difference between cows and bulls in order to separate the two groups a little more. In these results, it looks as though the TBV for the groups don't differ.


In [14]:
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
#labels = ax.set_xticklabels(grouped['level_1'].unique())
ax.set_title('Mean TBV for Bulls and Cows')
ax.set_xlabel('Generation')
ax.set_ylabel('True Breeding Value')
for key, grp in grouped.groupby(['level_0']):
    ax.plot(grp['TBV'], label=key)
ax.legend(loc='best')


Out[14]:
<matplotlib.legend.Legend at 0x10dab5910>

In the plot above it looks as though the bulls are "losing" their genetic base advantage in the first generation in which calves are produced. That's because they're being bred to cows that are not a good as they are, on average. Also, this plot includes all animals, including calves that died and cows and bulls that were culled without producing any offspring. A plot of the TBV of parents would be more informative as far as genetic trend goes. In order to do that, we need to count the number of offspring for each parent and merge them back into the all_animals data frame.


In [15]:
# How many calves did each bull sire?
sire_counts = pd.DataFrame(all_animals['sire'].value_counts(), columns=['offspring'])
# The Series index is the bull ID, which we want to convert to a column in the
# DataFrame.
sire_counts['animal'] = sire_counts.index
# We want to drop animal 0 because that's the unknown base-population sire.
sire_counts = sire_counts[sire_counts['animal'] > 0]
len(sire_counts)


Out[15]:
355

In [16]:
# How many calves did each cow produce?
dam_counts = pd.DataFrame(all_animals['dam'].value_counts(), columns=['offspring'])
# The Series index is the bull ID, which we want to convert to a column in the
# DataFrame.
dam_counts['animal'] = dam_counts.index
# We want to drop animal 0 because that's the unknown base-population sire.
dam_counts = dam_counts[dam_counts['animal'] > 0]
len(dam_counts)


Out[16]:
629390

In [17]:
# Now we do some merging. We must use LEFT OUTER JOINs in order to retain all animals
# even if they weren't parents.
with_sires = pd.merge(all_animals, sire_counts, on='animal', how='left')
with_dams = pd.merge(with_sires, dam_counts, on='animal', how='left')
all_animals = with_dams
all_animals['sex'].value_counts()


Out[17]:
F    915917
M    878005
dtype: int64

In [18]:
# These are cows
all_animals['offspring_y'].value_counts()


Out[18]:
1    192409
2    140974
3     99708
6     76607
4     72954
5     46717
dtype: int64

In [19]:
# These are bulls
all_animals['offspring_x'].value_counts()


Out[19]:
5000    294
4999     49
4998      6
4859      1
4514      1
2400      1
1431      1
288       1
141       1
dtype: int64

Is there something screwy going on? I don't expect cows to have thousands of offspring.

The thing is, we now have two different columns for the offspring counts, named "offspring_x" and "offspring_y". Can we just combine them using addition? (There's probably a clever way to do this in the join, but I don't know it.


In [20]:
all_animals['offspring_x'].fillna(0, inplace=True)
all_animals['offspring_y'].fillna(0, inplace=True)
all_animals['offspring'] = all_animals['offspring_x'] + all_animals['offspring_y']

What does the distribution of offspring counts look like?


In [21]:
parents = all_animals[all_animals['offspring'] > 0]
parents.hist(column='offspring', by='sex')


Out[21]:
array([<matplotlib.axes.AxesSubplot object at 0x10d8e5d90>,
       <matplotlib.axes.AxesSubplot object at 0x10d81a9d0>], dtype=object)

Now I think that we have everything we need in order to subset and plot genetic trend for parents, not just all animals.


In [22]:
grouped = parents.groupby(['sex','born']).mean()
full_index = []
for x in ['F','M']:
    for g in all_animals['born'].unique():
        full_index.append((x,g))
grouped = grouped.reindex(full_index).reset_index()
grouped = grouped.add_suffix('').reset_index()
grouped = grouped.sort(['level_0','level_1'])

In [23]:
fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
ax.set_title('Mean TBV for Parents')
ax.set_xlabel('Generation')
ax.set_ylabel('True Breeding Value')
for key, grp in grouped.groupby(['level_0']):
    ax.plot(grp['TBV'], label=key)
ax.legend(loc='best')


Out[23]:
<matplotlib.legend.Legend at 0x10ddabe90>

I also want to see what the inbreeding looks like. Plot by generation.


In [24]:
fig = plt.figure(figsize=fig_dims, dpi=300, facecolor='white')

# Set nicer limits
xmin ,xmax = 0, 30
ymin, ymax = 0, 0.25

ax = fig.add_subplot(1, 1, 1)
ax.set_xlabel('Generation')
ax.set_ylabel('Coefficient of inbreeding')
for key, grp in grouped.groupby(['level_0']):
    # This is producing the wrong labels on the x axis.
    if key == 'M': marker='s'
    else: marker = 'o'
    ax.plot(grp['inbreeding'], label=key, linewidth=2)
ax.legend(loc='best')

# Deal with ticks marks and labels
x_tick_locs = [t for t in xrange(0, 31, 5)]
x_tick_labels = [t for t in xrange(-10, 21, 5)]
xticks(x_tick_locs, x_tick_labels)

# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')

# Plot and save
fig.tight_layout(pad=0.1)  # Make the figure use all available whitespace
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-inbreeding.png', dpi=300)


Load the four allele frequency files.


In [40]:
rec_names = ['gen',
             'Brachyspina',
             'HH1',
             'HH2',
             'HH3',
             'HH4',
             'HH5',
             'BLAD',
             'CVM',
             'DUMPS',
             'Mulefoot',
             'Horned',
             'Red']

# We have 10 relicates for each simulation
for sim in xrange(1,11):
    # Load the individual history files
    freqs_random = pd.read_csv('horich/%s/minor_allele_frequencies_ran_holstein.txt'%sim, \
                       sep='\t', header=None, names=rec_names)

    freqs_toppct = pd.read_csv('horich/%s/minor_allele_frequencies_toppct_holstein.txt'%sim, \
                       sep='\t', header=None, names=rec_names)

    freqs_pryce = pd.read_csv('horich/%s/minor_allele_frequencies_pryce_holstein.txt'%sim, \
                       sep='\t', header=None, names=rec_names)

    freqs_rec = pd.read_csv('horich/%s/minor_allele_frequencies_pryce_r_holstein.txt'%sim, \
                       sep='\t', header=None, names=rec_names)
    
    freqs_random['rep'] = sim
    freqs_toppct['rep'] = sim
    freqs_pryce['rep'] = sim
    freqs_rec['rep'] = sim
    
    if sim == 1:
        all_random = freqs_random
        all_toppct = freqs_toppct
        all_pryce = freqs_pryce
        all_rec = freqs_rec
    else:
        all_random = pd.concat([all_random, freqs_random])
        all_toppct = pd.concat([all_toppct, freqs_toppct])
        all_pryce = pd.concat([all_pryce, freqs_pryce])
        all_rec = pd.concat([all_rec, freqs_rec])

Now we have final allele frequencies for each of the 10 replicates. We need to take the mean over the replicates for each recessive and plot those.


In [26]:
grouped_random = all_random.groupby(['gen']).mean()
grouped_toppct = all_toppct.groupby(['gen']).mean()
grouped_pryce = all_pryce.groupby(['gen']).mean()
grouped_rec = all_rec.groupby(['gen']).mean()

Plot the minor allele frequencies.


In [41]:
#fig = plt.figure(figsize=fig_dims, dpi=300, facecolor='white')
fig = plt.figure(figsize=(16, 12), dpi=300, facecolor='white')

# Set nicer limits
xmin ,xmax = 0, 20
ymin, ymax = 0, 0.10
recessives = rec_names[1:]

# Compute the expected frequency for each generation.
expected = {}
for i, r in enumerate(recessives):
    expected[r] = []
    # Red and horned are NOT lethals
    if r in ['Horned', 'Red']:
        for g in xrange(0,21):
                if g == 0:
                    expected[r].append(grouped_random[r][g])
                else:
                    q0 = expected[r][g-1]
                    p0 = 1. - q0
                    q1 = (p0*q0) + q0**2
                    expected[r].append(q1)        
    # The others are
    else:
        for g in xrange(0,21):
                if g == 0:
                    expected[r].append(grouped_random[r][g])
                else:
                    q0 = expected[r][g-1]
                    p0 = 1. - q0
                    q1 = (p0*q0) / (p0**2 + (2*p0*q0))
                    expected[r].append(q1)

# Now, plot all the things.                
colors = itertools.cycle(['r', 'g', 'b','k'])
markers = itertools.cycle(['o', 'v', 's', 'd', '^', '*'])
ax = fig.add_subplot(2, 2, 1)
ax.set_title('Random')
ax.set_xlabel('Generation')
ax.set_ylabel('Allele Frequency')
# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
for i, r in enumerate(recessives):
    if r != 'Horned':
        ax.plot(grouped_random[r], label=r, marker=markers.next(), c=colors.next(), lw=1.5)
        # Deal with ticks marks and labels
        x_tick_locs = [t for t in xrange(0, 21, 5)]
        x_tick_labels = [t for t in xrange(0, 21, 5)]
        xticks(x_tick_locs, x_tick_labels)
        # Despine
        ax = gca()
        ax.spines['right'].set_color('none')
        ax.spines['top'].set_color('none')
        ax.xaxis.set_ticks_position('bottom')
        ax.yaxis.set_ticks_position('left')

colors = itertools.cycle(['r', 'g', 'b','k'])
markers = itertools.cycle(['o', 'v', 's', 'd', '^', '*'])
ax = fig.add_subplot(2, 2, 2)
ax.set_title('Truncation')
ax.set_xlabel('Generation')
ax.set_ylabel('Allele Frequency')
# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
for i, r in enumerate(recessives):
    if r != 'Horned':
        ax.plot(grouped_toppct[r], label=r, marker=markers.next(), c=colors.next(), lw=1.5)
        # Deal with ticks marks and labels
        x_tick_locs = [t for t in xrange(0, 21, 5)]
        x_tick_labels = [t for t in xrange(0, 21, 5)]
        xticks(x_tick_locs, x_tick_labels)
        # Despine
        ax = gca()
        ax.spines['right'].set_color('none')
        ax.spines['top'].set_color('none')
        ax.xaxis.set_ticks_position('bottom')
        ax.yaxis.set_ticks_position('left')

colors = itertools.cycle(['r', 'g', 'b','k'])
markers = itertools.cycle(['o', 'v', 's', 'd', '^', '*'])
ax = fig.add_subplot(2, 2, 3)
ax.set_title('Pryce')
ax.set_xlabel('Generation')
ax.set_ylabel('Allele Frequency')
# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
for i, r in enumerate(recessives):
    if r != 'Horned':
        ax.plot(grouped_pryce[r], label=r, marker=markers.next(), c=colors.next(), lw=1.5)
        # Deal with ticks marks and labels
        x_tick_locs = [t for t in xrange(0, 21, 5)]
        x_tick_labels = [t for t in xrange(0, 21, 5)]
        xticks(x_tick_locs, x_tick_labels)
        # Despine
        ax = gca()
        ax.spines['right'].set_color('none')
        ax.spines['top'].set_color('none')
        ax.xaxis.set_ticks_position('bottom')
        ax.yaxis.set_ticks_position('left')

colors = itertools.cycle(['r', 'g', 'b','k'])
markers = itertools.cycle(['o', 'v', 's', 'd', '^', '*'])
ax = fig.add_subplot(2, 2, 4)
ax.set_title('Pryce + recessives')
ax.set_xlabel('Generation')
ax.set_ylabel('Allele Frequency')
# Despine
ax = gca()
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')
ax.xaxis.set_ticks_position('bottom')
ax.yaxis.set_ticks_position('left')
for i, r in enumerate(recessives):
    if r != 'Horned':
        ax.plot(grouped_rec[r], label=r, marker=markers.next(), c=colors.next(), lw=1.5)
        # Deal with ticks marks and labels
        x_tick_locs = [t for t in xrange(0, 21, 5)]
        x_tick_labels = [t for t in xrange(0, 21, 5)]
        xticks(x_tick_locs, x_tick_labels)
        # Despine
        ax = gca()
        ax.spines['right'].set_color('none')
        ax.spines['top'].set_color('none')
        ax.xaxis.set_ticks_position('bottom')
        ax.yaxis.set_ticks_position('left')

h, l = ax.get_legend_handles_labels()
leg = plt.figlegend(h, l, loc=(0.90, 0.8), fancybox=True)
rect = leg.get_frame()
rect.set_facecolor('white')
#suptitle = plt.suptitle('Allele Frequency Change Over Time for Several Mating Schemes', x = 0.5, y = 1.05, fontsize=18)

# Plot and save
#plt.tight_layout(pad=1., w_pad=0.5, h_pad=0.5)
fig.tight_layout(pad=0.1)  # Make the figure use all available whitespace
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-observed-allele-frequency-changes.png', dpi=300)


Let's try a small multiples-type of plot to show the actual versus expected frequencies.


In [42]:
fig = plt.figure(figsize=(16, 12), dpi=300, facecolor='white')

# Plot Pryce + recessives
colors = itertools.cycle(['r', 'g', 'b'])
for i, r in enumerate(recessives):
    ax = fig.add_subplot(4, 3, i)
    ax.set_title(r)
    ax.set_xlabel('Generation')
    ax.set_ylabel('Allele Frequency')
    ax.plot(grouped_rec[r], label='Observed', marker='o', c='k')
    ax.plot(expected[r], label='Expected', c='gray')
    if r == 'Horned':
        ax.set_ylim(0.0, 1.1)
    else:
        ax.set_ylim(0.0, 0.10)
    legend(loc='best')
        
plt.tight_layout(pad=1., w_pad=0.5, h_pad=0.5)
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-act-vs-exp-rec.png', dpi=300)


Let's take a look at just the Pryce inbreeding adjustment, then. See if it's less messy.


In [43]:
fig = plt.figure(figsize=(16, 12), dpi=300, facecolor='white')

# Plot Pryce + recessives
colors = itertools.cycle(['r', 'g', 'b'])
for i, r in enumerate(recessives):
    ax = fig.add_subplot(4, 3, i)
    ax.set_title(r)
    ax.set_xlabel('Generation')
    ax.set_ylabel('Allele Frequency')
    ax.plot(grouped_pryce[r], label='Observed', marker='o', c='k')
    ax.plot(expected[r], label='Expected', c='gray')
    if r == 'Horned':
        ax.set_ylim(0.0, 1.1)
    else:
        ax.set_ylim(0.0, 0.10)
    legend(loc='best')
        
plt.tight_layout(pad=1., w_pad=0.5, h_pad=0.5)
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-act-vs-exp-pryce.png', dpi=300)


Now we're going to fit a linear regression to each recessive in each scenario. The frequency is the dependent variable, and the generation number is the independent variable.


In [30]:
def fit_line(x, y):
    """Return RegressionResults instance of best-fit line."""
    X = sm.add_constant(x)
    model = sm.OLS(y, X, missing='drop')
    fit = model.fit()
    return fit

In [31]:
grouped_random_fits = {}
for i, r in enumerate(recessives):
    fit = fit_line(grouped_random.index.values, grouped_random[r])
    grouped_random_fits[r] = fit

grouped_toppct_fits = {}
for i, r in enumerate(recessives):
    fit = fit_line(grouped_toppct.index.values, grouped_toppct[r])
    grouped_toppct_fits[r] = fit
    
grouped_pryce_fits = {}
for i, r in enumerate(recessives):
    fit = fit_line(grouped_pryce.index.values, grouped_pryce[r])
    grouped_pryce_fits[r] = fit
    
grouped_rec_fits = {}
for i, r in enumerate(recessives):
    fit = fit_line(grouped_rec.index.values, grouped_rec[r])
    grouped_rec_fits[r] = fit
    
expected_fits = {}
for i, r in enumerate(recessives):
    fit = fit_line(grouped_rec.index.values, expected[r])
    expected_fits[r] = fit

In [32]:
from scipy.special import stdtr
def test_slopes(fit1, fit2, debug=False):
    """Perform a t-test of regression slopes assuming unequal variances."""
    sigma_b1_b2 = math.sqrt( fit1.bse[1]**2 + fit2.bse[1]**2 )
    t = (fit1.params[1] - fit2.params[1]) / sigma_b1_b2
    df = fit1.nobs + fit2.nobs - 4
    pvalue = 2*stdtr(df, -abs(t))
    if debug:
        print 'sigma_b1_b2: ', sigma_b1_b2
        print 'fit1.params[1]', fit1.params[1]
        print 'fit2.params[1]', fit2.params[1]
        print 'fit1.params[1] - fit2.params[1]', fit1.params[1] - fit2.params[1]
        print 't: ', t
        print 'df: ', df
        print 'pvalue: ', pvalue
    
    return t, pvalue

In [33]:
print 'Random versus Pryce+recessives'
for i, r in enumerate(recessives):
    tval, pval = test_slopes(grouped_random_fits[r], grouped_rec_fits[r])
    if pval < 0.05/11.: significant = '****'
    else: significant = ''
    print '\t%s:\tt = \t%s\tp = \t%s\t%s' % ( r, tval, pval, significant )


Random versus Pryce+recessives
	Brachyspina:	t = 	5.18953968728	p = 	7.33392438206e-06	****
	HH1:	t = 	6.02560973696	p = 	5.25037939385e-07	****
	HH2:	t = 	10.4187723191	p = 	1.07833922802e-12	****
	HH3:	t = 	-1.23961922576	p = 	0.222717442567	
	HH4:	t = 	-0.126807561609	p = 	0.899761339014	
	HH5:	t = 	3.63656386128	p = 	0.000816446185581	****
	BLAD:	t = 	7.63418518362	p = 	3.46744085032e-09	****
	CVM:	t = 	5.60713042545	p = 	1.96913374711e-06	****
	DUMPS:	t = 	-0.730447353021	p = 	0.469596534216	
	Mulefoot:	t = 	2.27085011058	p = 	0.0289080215849	
	Horned:	t = 	-4.00799364761	p = 	0.000275769578547	****
	Red:	t = 	2.72139454562	p = 	0.00975508473005	

In [34]:
print 'Pryce versus Pryce+recessives'
print '\tTrait\tb0_pryce\t\tb0_rec\t\t\tFaster\tt-value\t\tp-value\t\t\tsig'
print '\t%s' % ( '-'*110 )
for i, r in enumerate(recessives):
    tval, pval = test_slopes(grouped_pryce_fits[r], grouped_rec_fits[r])
    if pval < 0.05/11.: significant = '****'
    else: significant = ''
    if grouped_rec_fits[r].params[1] > grouped_pryce_fits[r].params[1]: bigger = 'P'
    else: bigger = 'R'
    if r == 'Brachyspina': rprint = 'Brachy'
    elif r == 'Mulefoot': rprint = 'Mule'
    else: rprint = r
    print '\t%s\t%s\t%s\t%s\t%s\t%s\t%s' % ( rprint, grouped_pryce_fits[r].params[1],
                                             grouped_rec_fits[r].params[1], bigger,
                                             tval, pval, significant )


Pryce versus Pryce+recessives
	Trait	b0_pryce		b0_rec			Faster	t-value		p-value			sig
	--------------------------------------------------------------------------------------------------------------
	Brachy	-0.000693642825756	-0.000978481406265	R	2.74021416925	0.0093019407263	
	HH1	-0.000560649179214	-0.000854506687409	R	1.85917599894	0.0707586797976	
	HH2	-0.000600999662286	-0.000827023435278	R	2.4830295204	0.0175571658862	
	HH3	-0.00115677464851	-0.000379253588772	P	-3.43032210504	0.00146650452861	****
	HH4	-0.000717612087016	7.84590634938e-05	P	-0.682652322211	0.498967310146	
	HH5	-0.00145403546421	-0.000650723905478	P	-3.58278649742	0.000952366242202	****
	BLAD	-0.000108242677528	-7.91355501366e-05	P	-1.3467082288	0.186051859764	
	CVM	-0.000553145841307	-0.000545047771784	P	-0.0992609491985	0.921452886107	
	DUMPS	-2.24857058078e-06	-2.18808092408e-06	P	-0.078436659663	0.937892298453	
	Mule	-4.1445893195e-05	-2.32183906402e-05	P	-2.18361433189	0.0352344726603	
	Horned	0.000321630541771	0.00015097137552	R	4.63853809297	4.07830109844e-05	****
	Red	-0.00147932393304	-0.00103500628228	P	-1.15907163016	0.253658912811	

In [35]:
print 'Pryce versus Expected'
print '\tTrait\tb0_rec\t\t\tb0_exp\t\t\tFaster\tt-value\t\tp-value\t\t\tsig'
print '\t%s' % ( '-'*110 )
for i, r in enumerate(recessives):
    tval, pval = test_slopes(grouped_pryce_fits[r], expected_fits[r])
    if pval < 0.05/11.: significant = '****'
    else: significant = ''
    if grouped_rec_fits[r].params[1] > expected_fits[r].params[1]: bigger = 'E'
    else: bigger = 'O'
    if r == 'Brachyspina': rprint = 'Brachy'
    elif r == 'Mulefoot': rprint = 'Mule'
    else: rprint = r
    print '\t%s\t%s\t%s\t%s\t%s\t%s\t%s' % ( rprint, grouped_pryce_fits[r].params[1],
                                             expected_fits[r].params[1], bigger,
                                             tval, pval, significant )


Pryce versus Expected
	Trait	b0_rec			b0_exp			Faster	t-value		p-value			sig
	--------------------------------------------------------------------------------------------------------------
	Brachy	-0.000693642825756	-0.000482812233646	O	-2.61091777195	0.0128536346139	
	HH1	-0.000560649179214	-0.000263968742125	O	-2.21613106352	0.0327451586855	
	HH2	-0.000600999662286	-0.000205430465115	O	-5.44132533126	3.32201002165e-06	****
	HH3	-0.00115677464851	-0.000537394899551	E	-3.36831309648	0.00174416835708	****
	HH4	-0.000717612087016	-1.27411884533e-05	E	-0.744634420375	0.461073298725	
	HH5	-0.00145403546421	-0.000337395004281	O	-6.24671942541	2.61265609334e-07	****
	BLAD	-0.000108242677528	-5.95116963483e-06	O	-7.54420658154	4.56860780806e-09	****
	CVM	-0.000553145841307	-0.000146587373394	O	-6.11411946332	3.97013381784e-07	****
	DUMPS	-2.24857058078e-06	-9.9800365138e-09	O	-4.14307584091	0.000184283048105	****
	Mule	-4.1445893195e-05	-4.83226727987e-07	O	-5.44257462112	3.30895703493e-06	****
	Horned	0.000321630541771	2.42861286637e-17	E	12.3192468573	7.67126352595e-15	****
	Red	-0.00147932393304	1.08420217249e-18	O	-5.58674438787	2.10000104493e-06	****

In [36]:
print 'Pryce+recessives versus Expected'
print '\tTrait\tb0_rec\t\t\tb0_exp\t\t\tFaster\tt-value\t\tp-value\t\t\tsig'
print '\t%s' % ( '-'*110 )
for i, r in enumerate(recessives):
    tval, pval = test_slopes(grouped_rec_fits[r], expected_fits[r])
    if pval < 0.05/11.: significant = '****'
    else: significant = ''
    if grouped_rec_fits[r].params[1] > expected_fits[r].params[1]: bigger = 'E'
    else: bigger = 'O'
    if r == 'Brachyspina': rprint = 'Brachy'
    elif r == 'Mulefoot': rprint = 'Mule'
    else: rprint = r
    print '\t%s\t%s\t%s\t%s\t%s\t%s\t%s' % ( rprint, grouped_rec_fits[r].params[1],
                                             expected_fits[r].params[1], bigger,
                                             tval, pval, significant )


Pryce+recessives versus Expected
	Trait	b0_rec			b0_exp			Faster	t-value		p-value			sig
	--------------------------------------------------------------------------------------------------------------
	Brachy	-0.000978481406265	-0.000482812233646	O	-7.28242677895	1.02349288e-08	****
	HH1	-0.000854506687409	-0.000263968742125	O	-7.00004186513	2.45897448884e-08	****
	HH2	-0.000827023435278	-0.000205430465115	O	-11.2964847104	1.03712099948e-13	****
	HH3	-0.000379253588772	-0.000537394899551	E	1.17733208921	0.246384582171	
	HH4	7.84590634938e-05	-1.27411884533e-05	E	0.133909495223	0.894180846096	
	HH5	-0.000650723905478	-0.000337395004281	O	-2.30759318893	0.0265624401545	
	BLAD	-7.91355501366e-05	-5.95116963483e-06	O	-4.3480518411	9.92520877886e-05	****
	CVM	-0.000545047771784	-0.000146587373394	O	-8.41152889421	3.31378598987e-10	****
	DUMPS	-2.18808092408e-06	-9.9800365138e-09	O	-3.95829257975	0.000319525821236	****
	Mule	-2.32183906402e-05	-4.83226727987e-07	O	-6.29754009754	2.22581481629e-07	****
	Horned	0.00015097137552	2.42861286637e-17	E	5.82387094101	9.93080781899e-07	****
	Red	-0.00103500628228	1.08420217249e-18	O	-3.73392349847	0.000616479399599	****

Reference figure for expected rate of allele frequency change.


In [37]:
fig = plt.figure(figsize=(16, 12), dpi=300, facecolor='white')

markers = itertools.cycle(['o', 'v', 's', 'd', '^', '*'])

# Compute the expected frequency for each generation.
expected = {}
for r in [0.01, 0.05, 0.10, 0.25, 0.75, 0.99]:
    expected[r] = []
    for g in xrange(0,21):
            if g == 0:
                expected[r].append(r)
            else:
                q0 = expected[r][g-1]
                p0 = 1. - q0
                q1 = (p0*q0) / (p0**2 + (2*p0*q0))
                expected[r].append(q1)
    
ax = fig.add_subplot(1, 1, 1)
#ax.set_title('Expected Change in Allele Frequencies')
ax.set_xlabel('Generation')
ax.set_ylabel('Allele Frequency')
for r in [0.01, 0.05, 0.10, 0.25, 0.75, 0.99]:
    l = 'Expected %s' % ( r )
    ax.plot(expected[r], label=l, c='k', lw=1.5, marker=markers.next())
ax.set_ylim(0.0, 1.0)
#legend = ax.legend(loc='upper right', shadow=False)
                
legend(loc='best')
plt.tight_layout(pad=1., w_pad=0.5, h_pad=0.5)
fig.savefig('/Users/jcole/Documents/AIPL/Genomics/Recessives/horich-expected-allele-frequency-change.png', dpi=300)



In [37]: