# How to create a circular histogram using matplotlib in python

by shivanisanju03 Updated: May 9, 2023

Solution Kit

A radial or circular histogram displays circular data. It involves wrapping the usual histogram around a circle. We center each bar in the histogram in the middle of the group period. It can be with the bar length proportional to the frequency in the group. A histogram is a graph showing a frequency distribution. It is a graph showing the number of observations in each given interval. The circular nature can cause difficulties when applying traditional linear and kernel-based methods. These methods must be better suited to handle the periodic nature of circular data.

But when plotting a circular histogram with a flat proportional to the radius. We have a disadvantage that you would never know. By looking at the areas, there are twice as many points in the (0, pi/4) bin as in the (-pi/4, 0) bin. But you can prevent this by labeling each bin with its corresponding density.

**Plotting a circular histogram: **

- To plot a circular (polar) histogram in Python, we can do the following steps
- Create data points for theta, radii, and width using numpy.
- Add a subplot to the current image where projection='polar' and nrows=1, ncols=1, and index=1.
- Create a bar chart using the bar () method with data points theta, radii, and width.

In this kit, we will see how to create a circular histogram using matplotlib in Python. We must first create data points for theta radii and width to plot circular histograms.

You can use the bar () method with theta, radii, and width data points. After zipping radii and bars together, we must iterate them and set the bar's face color and alpha value. The lesser the alpha value, gives greater the transparency. Then we must add a subplot to the current figure and make a bar plot.

Matplotlib helps create static, animated, and interactive visualizations. It creates publication-quality plots and makes interactive figures. The interactive figures can be updated, zoomed, and panned. It can make both easy and hard things possible.

**NumPy: **

This library works with Python arrays. It has functions to work in the domain of Fourier transform linear algebra and matrices.

Please check the code to learn how to create a circular histogram using matplotlib in Python.

Fig: Preview of the output that you will get on running this code from your IDE

### Code

### Instructions

__Follow the steps carefully to get the output easily.__

- Install PyCharm Community Edition on your computer.
- Open terminal and install the required libraries with following commands.
- Install Matplotlib - pip install matplotlib.
- Install NumPy - pip install numpy.
- Create a new Python file(eg: test.py).
- Copy the snippet using the 'copy' button and paste it into that file.
- Run the file using run button.

I hope you found this useful. I have added the link to dependent libraries, version information in the following sections.

*I found this code snippet by searching for **'circular histogram' **in kandi. You can try any such use case!*

### Environment Tested

I tested this solution in the following versions. Be mindful of changes when working with other versions.

- The solution is created in PyCharm 2022.3.3.
- The solution is tested on Python 3.9.7.
- Matplotlib version 3.7.1.
- NumPy version v1.24.2.

Using this solution, we are able to know how to create a circular histogram using matplotlib in python with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to know how to create a circular histogram using matplotlib in python

### Dependent Libraries

numpyby numpy

The fundamental package for scientific computing with Python.

numpyby numpy

Python 23755 Version:v1.25.0rc1 License: Permissive (BSD-3-Clause)

matplotlibby matplotlib

matplotlib: plotting with Python

matplotlibby matplotlib

Python 17559 Version:v3.7.1 License: No License

*You can also search for any dependent libraries on kandi like **'Matplotlib'** and **'NumPy'.*

### FAQ:

**1. What is a histogram bin, and how can it create a circular histogram in Python? **

The first step is to "bin" (or "stack") a range of values to construct a histogram. It helps divide the entire range of values into a series of intervals. It can count how many values fall into each interval. We can specify the bins as consecutive, non-overlapping intervals of a variable.

**2. How does a bar plot differ from a circular histogram when plotting data in Python Matplotlib? **

A bar chart represents a data category with rectangular bars. It can be with lengths and heights proportional to their values. The bar graph describes the comparison between individual categories. We can plot the bar charts horizontally or vertically. In contrast, a circular, polar, radial, or circular histogram displays circular data. It involves wrapping the usual histogram around a circle.

**3. How does the numpy library help create a circular histogram with Python Matplotlib? **

We must first create data points for theta radii and width to plot circular histograms.

**4. How to plot circular histograms in Python? **

Create data points for theta, radii, and width using numpy. Add a subplot to the current image where projection='polar' and nrows=1, ncols=1, and index=1. Create a bar chart using the bar() method with data points theta, radii, and width.

**5. What are the disadvantages of circular histograms? **

We have a disadvantage when we plot a histogram with an area proportional to the radius. By looking at the areas, you would never know that there are twice as many points in the (0, pi/4) bin as in the (-pi/4, 0) bin. But you can prevent this by labeling each bin with its corresponding density.

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