I have the following bar graph generated using pandas. My problem is all the bars have the same pattern. I have tried many approaches but could not manage to get around this issue.

Moreover, only one entry(for the last subplot) is shown in the legend.

The data used is

The code is :

import pandas as pd
import matplotlib.pyplot as plt
from matplotlib.ticker import ScalarFormatter
class ScalarFormatterForceFormat(ScalarFormatter):
    def _set_format(self):  # Override function that finds format to use.
        self.format = "%1.1f"  # Give format here
patterns = [ "\\" , "/" , "-"," " ,"x", "|", '.',  "O" ]
yfmt = ScalarFormatterForceFormat()
yfmt.set_powerlimits((0, 0))

bar_gap=0.005
bar_width=0.01

bar_pos = [0 for i in range(5)]
bar_pos[0]=bar_gap
for i in range(1,5):
    bar_pos[i]=bar_pos[i-1] bar_gap bar_width
colors = ['tab:blue', 'tab:green', 'tab:orange', 'tab:red','tab:olive']
patterns = [ "\\" , "/" , " " , "-", ".", "*","x", "o", "O" ]

# file_locn = ''r'C:\Users\girum\Desktop\Throughput.csv'''
file_locn = ''r'my_file.csv'''
df = pd.read_csv(file_locn,index_col='Set')
df=df.T
fig, axes = plt.subplots(1,3,figsize=(8,5))#,sharey=True)
for i in range(3):
    axes[i].yaxis.set_major_formatter(yfmt)
df.Type_A.plot(ax=axes[0],kind='bar',color=colors)
df.Type_B.plot(ax=axes[1],kind='bar',color=colors)
df.Type_C.plot(ax=axes[2],kind='bar',color=colors)

handles, labels = axes[0].get_legend_handles_labels()
for ax in fig.axes:
    bars = ax.patches
    hatches = ''.join(h*len(df) for h in patterns)

    for bar, hatch in zip(bars, hatches):
        bar.set_hatch(2*hatch)

plt.xticks(rotation=360)
axes[0].set_ylabel('Speed')
for i in range(len(df)):
    axes[i].set_xlabel('')#Why is this line not working
    axes[i].tick_params(axis='x', rotation=360)

plt.legend(loc='center right', bbox_to_anchor=(.2,1.08), ncol=1)

plt.show()

CodePudding user response：

The code below has the following changes:

• added some dummy test data to enable stand-alone test code
• removed some unused variables
• used the unaltered ScalarFormatter
• only one loop through the axes and avoiding the plt interface
• using ax.containers[0] to catch the bar container (ax.patches is a list of the rectangles, without the surrounding container)
• change the label of the bar container to _no_legend, so it doesn't appear in the legend
• used the patterns directly instead of concatenating them
• removed h*len(df); note that multiplying a string such as '/' by e.g. 4, repeats the string (to '////'); repeated patterns are used in matplotlib to make the base pattern denser
• used tick_params(axis='x', labelbottom=False, length=0) to remove the tick labels
• added labels to the individual bars so they appear into the legend

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import ScalarFormatter

yfmt = ScalarFormatter()
yfmt.set_powerlimits((-9, 9))

colors = ['tab:blue', 'tab:green', 'tab:orange', 'tab:red', 'tab:olive']
patterns = ["\\", "/", " ", "-", ".", "*", "x", "o", "O"]

df = pd.DataFrame(np.random.randint(100000, 500000, (3, 3)),
                  columns=['A', 'B', 'C'],
                  index=['Type_A', 'Type_B', 'Type_C'])
df = df.T
fig, axes = plt.subplots(1, 3, figsize=(8, 5))
df.Type_A.plot(ax=axes[0], kind='bar', color=colors)
df.Type_B.plot(ax=axes[1], kind='bar', color=colors)
df.Type_C.plot(ax=axes[2], kind='bar', color=colors)

for ax in axes:
    bars = ax.containers[0]
    bars.set_label('_no_legend')
    hatches = [h * 2 for h in patterns]
    for bar, hatch, label in zip(bars, hatches, df.index):
        bar.set_hatch(2 * hatch)
        bar.set_label(label)
    ax.yaxis.set_major_formatter(yfmt)
    ax.tick_params(axis='x', labelbottom=False, length=0)

axes[0].set_ylabel('Speed')

axes[2].legend(loc='lower right', bbox_to_anchor=(1, 1.01), ncol=3)
plt.tight_layout()
plt.show()

CodePudding user response：

The lines where you are joining the patterns generates a result, which you don't want.

patterns = [ "\\" , "/" , " " , "-", ".", "*","x", "o", "O" ]
hatches = ''.join(h*3 for h in patterns)
>>> '\\\\\\///   ---...***xxxoooOOO'

# if you have the bars, this is the output
for bar, hatch in zip([0,1,3], hatches):
    print(2*hatch)
>>>
\\
\\
\\

Try to simplify this section using the patterns in your loop directly:

for bar, hatch in zip([0,1,3], patterns):
    print(2*hatch)`
>>>
\\
//
  

Output

I used your given code and data to create this output.