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# 14- Plotting in Python

·Jun 28, 2021·

In this tutorial, you will learn how to plot different types of visualizations such as line plots, bar plots, pair plots, scatter plots, joint plots, pie charts, box plots, histograms, animated plots, and various types of categorical plots using libraries such as Matplotlib, Seaborn, and others.

First, download the datasets that we will be using in this tutorial: london_borough_profiles1.csv, myPub.csv, and sar_data.csv.

### Importing libraries

``````import re
import numpy as np
import pandas as pd
import random
import matplotlib as mpl
import matplotlib.pyplot as plt
import matplotlib.cbook as cbook
import seaborn as sns

from pylab import *
from mpl_toolkits.mplot3d import Axes3D
from matplotlib.colors import ListedColormap
``````

### Time plot (time series)

To plot the time variation of a single variable, use the following code:

``````# Load time series data at Github.

# define 'tplot' function
def tplot(df, x, y, title="", xlabel='Date', ylabel='Value', dpi=300):
plt.figure(figsize=(16,5), dpi=dpi)
plt.plot(x, y, marker='o', markerfacecolor='blue')
plt.gca().set(title=title, xlabel=xlabel, ylabel=ylabel)
plt.show()

tplot(df, x=df.index, y=df.value, title='Anti-diabetic sales in Australia from 1992 to 2008.')
``````

#### Seasonal plot of a time series

To plot a seasonal plot of a time series, use the following code:

``````
df.reset_index(inplace=True)

# Prepare data
df['year'] = [d.year for d in df.date]
df['month'] = [d.strftime('%b') for d in df.date]
years = df['year'].unique()

# Prepare Colors
np.random.seed(50)
mycolors = np.random.choice(list(mpl.colors.XKCD_COLORS.keys()), len(years), replace=False)

# Draw Plot
plt.figure(figsize=(15,10), dpi= 300)
for i, y in enumerate(years):
if i > 0:
plt.plot('month', 'value', data=df.loc[df.year==y, :], color=mycolors[i], label=y)
plt.text(df.loc[df.year==y, :].shape[0]-.9, df.loc[df.year==y, 'value'][-1:].values[0], y, fontsize=12, color=mycolors[i])

# Decoration
plt.gca().set(xlim=(-0.3, 11), ylim=(2, 30), ylabel='Drug Sales', xlabel='Month')
plt.yticks(fontsize=12, alpha=.7)
plt.subtitle("Seasonal plot of time series", fontsize=18)
plt.show()
``````

#### Plotting two variables time series:

``````
rs = np.random.RandomState(365) # create data
values = rs.randn(365, 2).cumsum(axis=0)
dates = pd.date_range("1 1 2021", periods=365, freq="D")
data = pd.DataFrame(values, dates, columns=["A", "B"])
data = data.rolling(7).mean()

sns.lineplot(data=data, palette="tab10", linewidth=2.5)
``````

### Annotated heatmaps

``````
# Load the example flights dataset and convert to long-form
flights = flights_long.pivot("month", "year", "passengers")

# Draw a heatmap with the numeric values in each cell
f, ax = plt.subplots(figsize=(9, 6))
sns.heatmap(flights, annot=True, fmt="d", linewidths=.5, ax=ax)
``````

### Swarmplot

Swarmplot used to display distribution of attributes.

``````
# Import csv file of data

# Create dataframe from some columns

df = df[['In_Out','Inner/_Outer_London', 'Happiness_score_2011-14_(out_of_10)', 'Anxiety_score_2011-14_(out_of_10)','Employment_rate_(%)_(2015)'
,'People_aged_17+_with_diabetes_(%)']]

# Cleaning data by change some names of columns

df.rename(columns={'Inner/_Outer_London': 'in_out','Happiness_score_2011-14_(out_of_10)':'happiness', 'Anxiety_score_2011-14_(out_of_10)':'anxiety', 'Employment_rate_(%)_(2015)':'employment','People_aged_17+_with_diabetes_(%)':'diabetes' }, inplace=True)

# Create some different data frames

df = df.reindex(columns=['diabetes', 'In_Out','in_out', 'happiness', 'anxiety', 'employment'])
df1 = df[['diabetes', 'happiness', 'anxiety']]
df2 = df[['in_out', 'employment', 'happiness', 'anxiety']]

# Create swarmplot using seaborn library

sns.swarmplot(data=df1)
plt.gca().set(ylabel='Value', xlabel='Indices') # set x and y labels
``````

### Barplot

A bar chart or bar graph is used to present categorical data.

``````sns.barplot(data=df1)
plt.gca().set(ylabel='Value', xlabel='Indices')
``````

#### Stacked Barplot

``````import matplotlib.pyplot as plt
labels = ['A', 'B', 'C', 'D', 'E']
men_av = [23, 25, 33, 30, 18]
women_av = [15, 22, 30, 10, 15]
std_m = [1, 2.5, 3, 1, 1.5]
std_w = [2, 4, 1.5, 2, 2.5]
width = 0.5       # the width of the bars: can also be len(x) sequence

fig, ba = plt.subplots()

ba.bar(labels, men_av, width, yerr=std_m, label='Men')
ba.bar(labels, women_av, width, yerr=std_w,
label='Women')

ba.set_ylabel('Scores')
ba.set_title('Scores by group and gender')
ba.legend()

plt.show()
``````

### Pairplot

Pairplot is used to present the distribution of variables and relationships between variables.

``````sns.pairplot(data=df2, hue='in_out')
``````

### Scatterplot

A scatter plot shows the relationship between two variables.

``````sns.scatterplot(data=df2, x = 'employment',y= 'happiness', hue='in_out')
plt.legend(title="", loc=8)
``````

#### 3D Scatterplot

``````

sns.set_style("whitegrid", {'axes.grid' : False})
fig = plt.figure()
ax = Axes3D(fig) # Method 1
#ax = fig.add_subplot(111, projection='3d') # Method 2
``````

Create x, y, and z NumPy array data.

``````X = np.array([0, 5, 10, 15, 20, 22, 26, 24, 14, 30])
Y = np.array([0, 3, 6, 9, 12, 22, 24, 26, 30, 20])
Z = np.array([3, 5, 11, 10, 12, 4, 5, 17, 10, 13])
``````

Get a colormap from the seaborn library.

``````cmap = ListedColormap(sns.color_palette("husl", 256).as_hex())
g = ax.scatter(X, Y, Z, c=X, s= 50, marker='o', cmap = cmap, alpha = 1)
``````

Set x, y, and z labels

``````ax.set_xlabel('X Label')
ax.set_ylabel('Y Label')
ax.set_zlabel('Z Label')
``````

Add a color bar that maps values to colors.

``````fig.colorbar( g, shrink=0.5, aspect=5)
plt.show()
``````

#### Use varying marker colors and sizes for the scatter plot.

``````data = pdr.DataReader('^DJI', 'stooq')# Data of ^DJI stooq market
data
data = data[-365:] # get the most recent 365 days data
delta1 = np.diff(data.Close) / data.Close[:-1] # price of close day / price of close day before
volume = (15 * data.Volume[:-2] / data.Volume[0])**2
``````

Set colors for 363 days from the seaborn library's color palette.

``````colors = sns.color_palette("Set3", 363)
``````

Plotting to scatter plot:

``````fig, pl = plt.subplots()
pl.scatter(delta1[:-1], delta1[1:], color=colors, s=volume, alpha = 0.5)
``````

Set x, y labels, and title:

``````pl.set_xlabel(r'Δi', fontsize=12)
pl.set_ylabel(r'Δi+1', fontsize=12)
pl.xaxis.label.set_color('midnightblue')
pl.yaxis.label.set_color('midnightblue')
pl.set_title('Scatter plot of ^DJI stooq with volume and price change')
pl.grid(True)
``````

Set x, y limitations

``````pl.axis([-0.025, 0.025, -0.025, 0.025]) # xlim , ylim
fig.tight_layout()
plt.show()
``````

### Jointplot

In addition to showing the relationship between the dependent variable (Y) and independent variable (X), it displays the distribution of X and Y.

``````# Linear regression
x = (1,3,5, 2, 9, 11)
y = (2,4,6, 3, 8, 10)
sns.jointplot (x=x, y=y, data =df , kind = "reg")
plt.gca().set(ylabel='Y', xlabel='X')
``````

### Piechart

``````
# create data
names='A', 'B', 'C', 'D',
values=[5, 15, 30, 50]

# create a pieplot
plt.pie(values, labels = names, labeldistance=1.15, shadow=True, startangle=90, autopct='%1.1f%%')# Label distance: gives the space between labels and the center of the pie
plt.show()
``````

### Boxplot

``````df = pd.read_csv (r'D:\Python\Python_for_Researchers\sar_data.csv', encoding='unicode_escape')

sns.boxplot(data=df,palette=["m", "g"])
sns.despine(offset=10, trim=True)
plt.gca().set(ylabel='Value', xlabel='Sensor')
``````

### Histogram

It represents the distribution of numerical data.

``````bio = [-2, 1, 2, 4, 2, 5, 5, 5,6 , 7, 9, 7, 5, 10, 15] # create data

sns.set_style('darkgrid') # set grid style
his = sns.distplot(bio)
his.set_xlabel('Value', fontsize=12) # set x label
his.set_ylabel('Frequency', fontsize=12) # set y label
``````

### Animated plot in Python

``````### Animated plot in Python

# Check the first 5 rows

# And I need to transform my categorical column (continent) in a numerical value group1->1, group2->2...
data['Open']=pd.Categorical(data['Open'])

# For each year:
for i in data.Year.unique():

# Turn interactive plotting off
plt.ioff()

# initialize a figure
fig = plt.figure(figsize=(10, 6))

# Find the subset of the dataset for the current year
subsetData = data[ data.Year == i ]

# Build the scatterplot
plt.scatter(
x=subsetData['Cum_Publications'],
y=subsetData['Cum_Citations'],
s=subsetData['Cum_Citations']*15,
edgecolors="white", linewidth=2, color = 'midnightblue')

# Add titles (main and on axis)
plt.yscale('linear')
plt.xlabel("Publication")
plt.ylabel("Citation"),
plt.title("Azad Rasul's Cumulative Publications and Citations during: "+str(i) )
plt.ylim(-50, 500)
plt.xlim(0, 25)

# Save it & close the figure
plt.savefig(fname=filename, dpi=96)
plt.gca()
plt.close(fig)
# To convert a list of png figures to a gif video online, use a website such as https://gifmaker.me/.
``````

#### Animated scatterplot

``````#### Animated scatterplot

# read the data (on the web)

# Check the first 2 rows

# And I need to transform my categorical column (continent) in a numerical value group1->1, group2->2...
data['continent']=pd.Categorical(data['continent'])

# Set the figure size
plt.figure(figsize=(10, 10))

# Subset of the data for year 1952
data1952 = data[ data.year == 1952 ]

# image resolution
dpi=96

# For each year:
for i in data.year.unique():

# Turn interactive plotting off
plt.ioff()

# initialize a figure
fig = plt.figure(figsize=(680/dpi, 480/dpi), dpi=dpi)

# Find the subset of the dataset for the current year
subsetData = data[ data.year == i ]

# Build the scatterplot
plt.scatter(
x=subsetData['lifeExp'],
y=subsetData['gdpPercap'],
s=subsetData['pop']/200000 ,
c=subsetData['continent'].cat.codes,
cmap="Accent", alpha=0.6, edgecolors="white", linewidth=2)

# Add titles (main and on axis)
plt.yscale('log')
plt.xlabel("Life Expectancy")
plt.ylabel("GDP per Capita")
plt.title("Year: "+str(i) )
#    plt.ylim(0,100000)
plt.xlim(30, 90)

# Save it & close the figure
plt.savefig(fname=filename, dpi=96)
plt.gca()
plt.close(fig)
# conver to gif video online: https://gifmaker.me/
``````

### Categorical data (catplot)

If the variables are "categorical" (divided into discrete groups), it may be advantageous to use catplot. We can change the plot type by changing the "kind" parameter to violin, swarm, boxen, strip, box, point, bar, or count.

#### Violin Catplot

Load the titanic.csv file using the load_dataset function from the Seaborn library.

``````titanic = sns.load_dataset("titanic") # load titanic csv file from seaborn lab

g = sns.catplot(x='pclass', y="age",
hue="alive",  # catigorize and change the color by alive column data
data=titanic, kind='violin', legend_out=False) # legend_out = Faluse to move legend to inside the plot
plt.legend(title="Alive", loc=1) # Location: 'upper right':1
``````

#### Swarm Catplot

``````titanic = sns.load_dataset("titanic") # load data

g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='swarm', legend_out=False)
plt.axis([-1, 3, 0, 90]) # xlim , ylim
plt.legend(title="Alive", loc=9) # Location: 'upper center':9
``````

#### Boxen Catplot

``````titanic = sns.load_dataset("titanic")
g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='boxen', legend_out = False)
plt.axis([-1, 3, 0, 90]) # xlim , ylim
plt.legend(title='Alive', loc = 9)
``````

#### Strip Catplot

``````titanic = sns.load_dataset("titanic")
g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='strip', legend_out=False)

plt.axis([-1, 3, 0, 90]) # xlim , ylim
plt.legend(title='Alive', loc = 9)
``````

#### Box Catplot

``````titanic = sns.load_dataset("titanic")
g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='box')
``````

#### Point Catplot

``````titanic = sns.load_dataset("titanic")
g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='point', legend_out = False)
``````

#### Bar Catplot

``````titanic = sns.load_dataset("titanic")
g = sns.catplot(x='pclass', y="age",
hue="alive",
data=titanic, kind='bar', legend_out = False)
``````

#### Count Catplot

``````sns.catplot( x='embark_town',
kind="count",
hue= "sex",
data=titanic,
height=5,
aspect=1.5, legend_out = False)
plt.xlabel("Embark town", size=14)
plt.ylabel("Count", size=14)
#plt.tight_layout()
plt.legend(title="Gender", loc=9) # Location: 'upper center':9
``````