Matplotlib Bar Chart – Python Matplotlib Tutorial

Matplotlib Bar Chart

To visualize value associated with categorical data in the bar format use matplotlib bar chart plt.bar() or plt.barh() methods.

Importing Libary to Plot Bar Chart

import matplotlib.pyplot as plt
import numpy as np
from matplotlib import style

Importing Data set to plot Bar Chart

This dataset of “Indian Artificial Intelligence Production Class” (IAIP).  Instead of it use your business dataset.

# Dataset of 'Indian Artificial Intelligence Production (IAIP) Class"

#classes = ["Python", "R", "Artificial Intelligence", "Machine Learning", "Data Science"]

classes = ["Python", "R", "AI", "ML", "DS"]
class1_students = [30, 10, 20, 25, 10] # out of 100 student in each class
class2_students = [40, 5, 20, 20, 10]
class3_students = [35, 5, 30, 15, 15]

Plot Bar Chart with a different way

To plot bar chart using the matplotlib python library, use plt.bar() or plt.barh() methods.

Syntax: plt.bar(
                             x,
                             height,
                             width=0.8,
                             bottom=None,
                             *,
                             align=’center’,
                             data=None,
                             **kwargs,
                             )

Parameters

———-
x : sequence of scalars
height : scalar or sequence of scalars
width : scalar or array-like, optional …….(default: 0.8).
bottom : scalar or array-like, optional
align : {‘center’, ‘edge’}, optional, ……….default: ‘center’

Other Parameters
—————-

color : scalar or array-like, optional
edgecolor : scalar or array-like, optional
linewidth : scalar or array-like, optional
tick_label : string or array-like, optional ……. name of Bar
xerr, yerr : scalar or array-like of shape(N,) or shape(2,N), optional
ecolor : scalar or array-like, optional, default: ‘black’
capsize : scalar, optional
error_kw : dict, optional
log : bool, optional, default: False
orientation : {‘vertical’, ‘horizontal’}, optional

See also
——–
barh: Plot a horizontal bar plot.

Other optional kwargs:

agg_filter: a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array
===== alpha: float or None
animated: bool
antialiased: unknown
capstyle: {‘butt’, ’round’, ‘projecting’}
clip_box: `.Bbox`
clip_on: bool
clip_path: [(`~matplotlib.path.Path`, `.Transform`) | `.Patch` | None]
===== color: color
contains: callable
===== edgecolor: color or None or ‘auto’
===== facecolor: color or None
===== figure: `.Figure`
fill: bool
gid: str
hatch: {‘/’, ‘\\’, ‘|’, ‘-‘, ‘+’, ‘x’, ‘o’, ‘O’, ‘.’, ‘*’}
in_layout: bool
joinstyle: {‘miter’, ’round’, ‘bevel’}
===== label: object
===== linestyle: {‘-‘, ‘–‘, ‘-.’, ‘:’, ”, (offset, on-off-seq), …}
===== linewidth: float or None for default
path_effects: `.AbstractPathEffect`
picker: None or bool or float or callable
rasterized: bool or None
sketch_params: (scale: float, length: float, randomness: float)
snap: bool or None
transform: `.Transform`
url: str
===== visible: bool
zorder: float

plt.bar(classes, class1_students) # Plot vertical Bar Chart

Output >>>

plt.barh(classes, class1_students) # Plot horizontal bar chart 

Output >>>

Use multiple parameters of plt.bar() method

plt.bar(classes, class1_students, width = 0.2, align = "edge", color = "y",
       edgecolor = "m", linewidth = 5, alpha = 0.9, linestyle = "--",
       label =" Class 1 Students", visible=False)
#visible = True ## bar Chart will hide 

Output >>> 

Increase figure size and use style.

style.use("ggplot") 
plt.figure(figsize=(16,9)) # figure size with ratio 16:9
plt.bar(classes, class1_students, width = 0.6, align = "edge", color = "k",
       edgecolor = "m", linewidth = 5, alpha = 0.9, linestyle = "--",
       label =" Class 1 Students") #visible=False

Output >>>

Plot horizontal bar chart with the above specification. 

plt.figure(figsize=(16,9))
plt.barh(classes, class1_students,  align = "edge", color = "k",
       edgecolor = "m", linewidth = 5, alpha = 0.9, linestyle = "--",
       label =" Class 1 Students") #visible=False

Output >>>

Decorating bar chart using multiple functions.

plt.figure(figsize=(16,9))
plt.bar(classes, class1_students, width = 0.6, align = "edge", color = "k",
       edgecolor = "m", linewidth = 5, alpha = 0.9, linestyle = "--",
       label =" Class 1 Students") #visible=False

plt.title("Bar Chart of IAIP Class", fontsize = 18)
plt.xlabel("Classes",fontsize = 15)
plt.ylabel("No. of Students", fontsize = 15)
plt.show()

Output >>>

Trying to plot two bar charts with a different dataset.

plt.figure(figsize=(16,9))

plt.bar(classes, class1_students, width = 0.2, color = "b",
        label =" Class 1 Students") #visible=False

plt.bar(classes, class2_students, width = 0.2, color = "g",
        label =" Class 2 Students") 

plt.title("Bar Chart of IAIP Class", fontsize = 18)
plt.xlabel("Classes",fontsize = 15)
plt.ylabel("No. of Students", fontsize = 15)
plt.show()

Output >>>

The above code not generating two bar charts in one figure but they are overlapping. So use the below code to plot multiple bar charts. In below chart plot three bar charts using three different datasets.

plt.figure(figsize=(16,9))

classes_index = np.arange(len(classes))

width = 0.2

plt.bar(classes_index, class1_students, width , color = "b",
        label =" Class 1 Students") #visible=False

plt.bar(classes_index + width, class2_students, width , color = "g",
        label =" Class 2 Students") 

plt.bar(classes_index + width + width, class3_students, width , color = "y",
        label =" Class 2 Students") 

plt.xticks(classes_index + width, classes, rotation = 20)
plt.title("Bar Chart of IAIP Class", fontsize = 18)
plt.xlabel("Classes",fontsize = 15)
plt.ylabel("No. of Students", fontsize = 15)
plt.show()

Output >>>

Plot Matplotlib Horizontal bar chart with the above specification.

plt.figure(figsize=(16,9))

classes_index = np.arange(len(classes))

width = 0.2

plt.barh(classes_index, class1_students, width , color = "b",
        label =" Class 1 Students") #visible=False

plt.barh(classes_index + width, class2_students, width , color = "g",
        label =" Class 2 Students") 

plt.barh(classes_index + width + width, class3_students, width , color = "y",
        label =" Class 3 Students") 

plt.yticks(classes_index + width, classes, rotation = 20)
plt.title("Bar Chart of IAIP Class", fontsize = 18)
plt.ylabel("Classes",fontsize = 15)
plt.xlabel("No. of Students", fontsize = 15)
plt.legend()
plt.show()

Output >>>

Conclusion

In the matplotlib bar chart blog, we learn how to plot one and multiple bar charts with a real-time example using plt.bar() and plt.barh() methods. Along with that used different method and different parameter. We suggest you make your hand dirty with each and every parameter of the above methods. This is the best coding practice. After completion of the matplotlib tutorial jump on Seaborn.

Download Jupyter file of matplotlib bar chart source code

Visit to the official site of matplotlib.org