### Python Matplotlib

• date 8th March, 2021 |
• by Prwatech |

Prerequisites

Hardware : Local Machine

Software : Jupyter Notebook

Programming Language : Python

Definition:

Matplotlib is a cross-platform, data visualization and graphical plotting for Python.

Jupyter Notebook Introduction:

Jupyter is a free, open-source, interactive web tool which known as a computational notebook, which anybody can use to combine software code to get the computational output, explanatory text in a single document.

PLOT A LINE IN Matplotlib:

You can run the following code in Jupyter Notebook:

Click this link to open Jupyter Notebook – https://jupyter.org/

plt.plot() –

A function which is used to plot the points between x and y.

plt.show()

Function which shows the plot.

What is Matplotlib?

matplotlib.pyplot is a collection of command style functions which makes matplotlib work like MATLAB

Each `pyplot` function can make any changes to a figure. For example It can create a figure, It can also create a plotting area in the figure, A function which plots some lines in a plotting area

What is Pyplot?

Pyplot package can be considered as `plt`.

SIMPLE PLOT:

Let’s display a simple line plot by using the math module which uses mathematical functions.

Here is the program for the reference Simple Plot:

What is Numpy?

NumPy is a module for the Python programming language for large multi-dimensional arrays and matrices

import numpy as np – In simple terms making short “numpy” to “np” to make your code easier to read.

import math – . The math module uses mathematical functions

np.arrange()

NumPy `arange()` Creation of an array using routines based on numerical ranges. It is also for Setting the coordinates

np.sin() –

It is a mathematical function which helps user to calculate trignometric sine.

plt.plot() –

A function which is used to plot the points between x and y.

MULTI PLOT:

This allows to draw multiple graphs in a single plot.

A subplot () function is known as wrapper function which allows user to plot more than one graph in a single figure

Here is the program for the reference Multi Plot:

plt.plot([1, 2, 3)]

Plot a line, Implicitly creating a subplot

What is a Subplot?

Subplots can connect to main plots.

plt.subplot(211)

Creation of a subplot that represents the top plot of a grid with 2 rows and 1 column.

plt.subplot(212, facecolor=’y’)

As we can see it creates 2nd subplot with yellow background

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BAR PLOT:

A bar graph is the visualization which shows the comparison among discrete categories. X axis of the chart shows the categories which are compared, and Y axis represents a measured value.

Here is the program for reference for Bar Plot:

fig = plt.figure()

figure() A function which is used to create a figure object.

` `

It is a figure module of matplotlib which is used to add axes to the figure.

ax.bar()

A module of matplotlib is used to make a bar plot.

plt.show()

Function to show the plot.

HISTOGRAM:

A histogram represents the numerical data. It is also known as the other form of Bar Graph.

Here is the program for the reference Histogram:

np.array()

A function which includes Array elements

ax.hist()

It is an essential function that is used to plot a histogram graph.

ax.set()

A function which is know to be a property, In other words it is a batch setter, Be it Title set or a Label Set

plt.show()

A function to show the plot.

PIE CHART:

A Pie Chart displays one series of data. Pie charts shows the size of subjects in one data series in different divisions, The data points are shown in percentage in a Pie chart.

Here is the program for the reference Pie Chart:

import numpy as np

In simple terms making short “numpy” to “np” to make your code easier to read.

fig = plt.figure()

figure() A function which is used to create a figure object.

ax.pie

A function of Matplotlib library which is used to plot a pie chart Graph.

plt.show()

A function to show the plot.

Matplotlib – Scatter Plot

Scatter plots are knows to be used of plotting data points on horizontal and vertical axis in the attempt to show how much one variable is affected by another.

A scatter plot is a diagram which is displayed in a graphical format where each value in the data set is represented by a single dot.

Here is a program for the reference Scatter Plot:

fig = plt.figure()

figure() A function which is used to create a figure object.

ax.scatter

It is a module of Matplotlib library which is used to plot a scatter plot graph.

ax.set_title()

To set the Title on the Top of the Graph

CONTOUR PLOT

Contour plots displays a 3 dimensional surface on 2 – dimensional plane.

Here is the program for the reference Contour Plot:

np.linespace

The nplinspace is a tool in Python for creating numeric sequences. It is kind of similar to np.arrange() function.

np.meshgrid

The `numpy.meshgrid` function is used to create a rectangular grid out of two given 1 – dimensional arrays.

np.sqrt

A Function which is used to determine the positive square-root of an array, in a specific way, element-wise.

ax.contour

It is a function of matplotlib is used to Plot contours. contourdraw contour lines.

fig.colorbar(cp)

It is a function of matplotlib is used to add a color bar to a plot.

ax.set_title()

To set the Title on the Top of the Graph

plt.show()

A function to show the plot.

QUIVER PLOT

A quiver plot displays the velocity vectors as arrows with components.

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Here is the program for the reference Quiver Plot:

VIOLIN PLOT

Violin plots are identical to box plots, exception is that they also show the probability density of the data at different pace of values.

A violin plot is much more informative than a plain box plot.

Here is the program for the reference Violin Plot:

3 D CONTOUR PLOT

ax.contour3D()

It is a function creates three-dimensional contour plot.

Here is the program for the reference 3D Contour Plot:

Output:

3D WIREFRAME PLOT

Wireframe plot takes a grid of values and projects it onto the specified three-dimensional surface

Here is the program for the reference 3D Wireframe plot:

Output:

GRIDS

The grid() function of axes object sets visibility of grid inside the figure to on or off.

Here is the program for the reference Grids:

Output:

### Quick Support  