How to write values over matplotlib bar charts without distorted figures - python-3.x

Question

NOTE
The answers here produce a distorted figure; here is the bad result:
Here is the modified code that produces the bad result:
def plot_compare_bar(col1, col2, frame, fig_prefix=''):
frame = frame.sort_values(by=col1)
ind = np.arange(len(frame))
width = 0.4
fig, ax = plt.subplots(figsize=(9, 5))
ax.barh(ind, frame[col1], width, color='red', label=col1)
ax.barh(ind + width, frame[col2], width, color='blue', label=col2)
ax.set(
yticks=ind + width, yticklabels=frame['Class Name'],
ylim=[2 * width - 1, len(frame)], title=(
f'{fig_prefix} {col1} vs {col2} evaluation results'))
for i, v in enumerate(frame[col1].values):
ax.text(v + 3, i + .25, str(v), color='red', fontweight='bold')
for i, v in enumerate(frame[col2].values):
ax.text(v + 3, i + .25, str(v), color='blue', fontweight='bold')
ax.legend()
The original question:
import matplotlib.pyplot as plt
import numpy as np
def plot_compare_bar(col1, col2, frame, fig_prefix=''):
frame = frame.sort_values(by=col1)
ind = np.arange(len(frame))
width = 0.4
fig, ax = plt.subplots(figsize=(9, 5))
ax.barh(ind, frame[col1], width, color='red', label=col1)
ax.barh(ind + width, frame[col2], width, color='blue', label=col2)
ax.set(
yticks=ind + width, yticklabels=frame['Class Name'],
ylim=[2 * width - 1, len(frame)], title=(
f'{fig_prefix} {col1} vs {col2} evaluation results'))
ax.legend()
frame is a pandas DataFrame that looks like the following:
Class Name Average Precision Actual Detections True Positives False Positives Combined
2 Palm Tree 91.152760 1379 1428 1292 141 1433
5 Traffic Lights 71.026533 1269 1036 948 88 1036
3 Street Lamp 63.871910 995 848 727 121 848
0 Car 57.535491 3153 1955 1881 104 1985
1 Street Sign 56.925982 1109 704 658 46 704
6 Pedestrian 55.243564 1418 887 835 73 908
13 Road Block 52.182602 363 215 203 14 217
4 Minivan 51.786659 68 41 38 3 41
11 Bus 36.805556 43 18 16 2 18
9 Trash Can 14.444444 90 13 13 0 13
10 Bicycle 5.882353 17 1 1 0 1
8 Flag 5.000000 124 10 7 3 10
7 Fire Hydrant 1.923077 52 1 1 0 1
12 Pickup Truck 0.000000 20 0 0 0 0
14 Delivery Truck 0.000000 4 0 0 0 0
15 Motorcycle 0.000000 3 0 0 0 0
The function I defined above, produces the following plot:
I need every bar's value written next to it which might look like this:
How to modify the function above to do it.

Answer 1

You should not hard-coded the text. Instead, try to extract the values from patches:
def plot_compare_bar(col1, col2, frame, fig_prefix=''):
frame = frame.sort_values(by=col1)
ind = np.arange(len(frame))
width = 0.4
fig, ax = plt.subplots(figsize=(10,10))
ax.barh(ind, frame[col1], width, color='red', label=col1)
ax.barh(ind + width, frame[col2], width, color='blue', label=col2)
ax.set(
yticks=ind + width, yticklabels=frame['Class Name'],
ylim=[2 * width - 1, len(frame)], title=(
f'{fig_prefix} {col1} vs {col2} evaluation results'))
# annotation here
for patch in ax.patches:
# extract information from patch
pw = patch.get_width()
_,y = patch.get_xy()
color = patch.get_facecolor()
ax.text(pw + 3, y + width/2, str(pw),
color=color,verticalalignment='center')
ax.legend(loc='lower right')
Output: