## Adjusting Line Thickness in Matplotlib Plots

Matplotlib is a commonly used Python visualization library for creating a wide variety of graphs and charts. One essential aspect of creating visualizations is the ability to adjust the line thickness of your plots.

In this article, we will explore the different ways to adjust line thickness in Matplotlib plots.

## 1. Using linewidth argument function

Matplotlib provides a linewidth function that enables you to adjust the thickness of the lines in your plots. By default, the linewidth is set to 1.0, but you can adjust this as needed.

To use the function, you can specify the desired width of your lines as an argument to the function. For example, suppose you want to create a line chart for a set of x and y values and set the thickness of the line to 2.

### You can use the following function:

```
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(0, 5, 10)
y = np.sin(x)
plt.plot(x, y, linewidth=2)
plt.show()
```

## 2. Changing default line width

You may find that the default line width does not meet your desired visual goals. To change the default line width throughout your plot, you can use the rcParam function.

This function enables you to set various display parameters of your plots, including the linewidth. To adjust the linewidth using rcParam, you can do the following:

```
import matplotlib as mpl
import matplotlib.pyplot as plt
mpl.rcParams['lines.linewidth'] = 2
```

## 3. Creating line chart with custom line width

You may want to create your custom line width for specific parts of a plot, such as the horizontal or vertical axis lines. Additionally, you might want to use different line widths to highlight certain trends or events.

You can do this by using the plot function’s linewidth parameter to adjust the line’s thickness. For example, let’s say you want to create a line chart for data where the x-axis range from 1 to 10 and y-axis is a random set of numbers.

You want to plot the horizontal axis with a thickness of 2 and the y-axis with a thickness of 4 and after that set the thickness of the plotting line to 1. Here’s the code to produce such a plot:

```
import matplotlib.pyplot as plt
import numpy as np
x = range(1, 11)
y = np.random.randint(1, 20, size=len(x))
plt.plot(x, y, linewidth=1)
plt.axhline(0, color='black', linewidth=2)
plt.axvline(0, color='black', linewidth=4)
```

## 4. Adjusting thickness of multiple lines

As a data analyst or scientist, you may have to plot multiple series of data in your plot. Suppose you want to adjust the line thickness of these multiple series.

You can do this by specifying different linewidths for each line in the plot. For example, let’s say you want to plot three lines, where the first is a thick line with thickness 4, the second is a medium thickness line with thickness 2, and the third is a thin line with thickness 1.

### Here is the code you can use:

```
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(0, 10, 1000)
y1 = np.sin(x)
y2 = np.cos(x)
y3 = np.tan(x)
plt.plot(x, y1, linewidth=4)
plt.plot(x, y2, linewidth=2)
plt.plot(x, y3, linewidth=1)
```

## 5. Adjusting line thickness in legends

Suppose you want to adjust the line thickness of your legend display, you can specify the linewidth in the legend arguments provided by the plt.legend() function. For example, let’s say that you want to create a plot where the legend is displayed with a slightly thicker line.

### You can use the following code to achieve this:

```
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(0, 5, 10)
y = np.sin(x)
plt.plot(x, y, linewidth=2, label='my plot')
plt.legend(loc='lower right', frameon=True, framealpha=1, linewidth=2)
plt.show()
```

## Conclusion

Matplotlib provides several ways to adjust the line thickness in your plots. You can use the linewidth function to specify a specific line thickness, change the default thickness using rcParam, create a custom line width for different parts of your plot, adjust the thickness of multiple lines, or adjust line thickness in legends.

By understanding these different methods, you can create visually appealing and informative plots tailored to your specific needs. 3) Example 2: Adjusting Thickness of Multiple Lines

Matplotlib allows you to create charts with multiple lines, each with varying thicknesses to show different trends or patterns in data.

To adjust multiple line thicknesses in Matplotlib, we first define the x and y values for each line. After that, we can call the plot() function multiple times, each with a different set of data and a different value for the “linewidth” parameter to adjust line thickness.

Let’s suppose we want to compare the patterns of three different sinusoidal waves with varying frequencies. We can use NumPy to generate arrays for x and y values.

We can then pass these arrays to the plot() function three times, each with a different linewidth:

```
import matplotlib.pyplot as plt
import numpy as np
# Define x values
x = np.linspace(0, 10, 1000)
# Define y values for each line
y1 = np.sin(2 * np.pi * x)
y2 = np.sin(3 * np.pi * x)
y3 = np.sin(4 * np.pi * x)
# Plot multiple lines with varying thicknesses
plt.plot(x, y1, linewidth=1, label='2pi')
plt.plot(x, y2, linewidth=2, label='3pi')
plt.plot(x, y3, linewidth=3, label='4pi')
# Display the plot
plt.legend()
plt.show()
```

In the above example, we have plotted three sinusoidal waves with different frequencies and line thicknesses. The first line has a frequency of 2 and a linewidth of 1, the second line has a frequency of 3 and a linewidth of 2, while the third line has a frequency of 4 and a linewidth of 3.

By customizing the linewidths, we can quickly see that the higher frequency lines have thicker lines, with the thinnest being the lowest frequency line. 4) Example 3: Adjusting Line Thickness in Legends

Legend is an essential element of a plot, which helps in identifying different elements of the chart.

You can adjust the line thickness of the legend using the “linewidth” parameter in the plt.legend() function.

Suppose we want to display a plot of three different sinusoidal lines with varying frequencies and line thicknesses.

We can create these lines and plot them as shown in Example 2. We can then add a legend to our plot using the plt.legend() function and pass the “linewidth” parameter to adjust the legend’s line thickness.

```
import matplotlib.pyplot as plt
import numpy as np
# Define x values
x = np.linspace(0, 10, 1000)
# Define y values for each line
y1 = np.sin(2 * np.pi * x)
y2 = np.sin(3 * np.pi * x)
y3 = np.sin(4 * np.pi * x)
# Plot multiple lines with varying thicknesses
plt.plot(x, y1, linewidth=1, label='2pi')
plt.plot(x, y2, linewidth=2, label='3pi')
plt.plot(x, y3, linewidth=3, label='4pi')
# Add legend to the plot
plt.legend(loc='upper right', frameon=True, framealpha=1, facecolor='white', edgecolor='black', title='Frequency', title_fontsize=18, borderpad=1, labelspacing=1, handlelength=2, handleheight=2, handletextpad=1, fontsize=12, linewidth=2)
# Display the plot
plt.show()
```

In the above example, we have added a legend to a chart with multiple lines, each with varying thicknesses. We have adjusted the thickness of the legend using the “linewidth” parameter and have set some other formatting options, such as frame, framealpha, facecolor, edgecolor, and fontsize, to enhance the plot’s visual appeal.

By customizing these settings, we can create a legible and informative chart that contains information about each element of the plot.

## Conclusion

Matplotlib provides several ways to adjust line thickness in a plot, from adjusting a single line thickness to multiple lines and adjusting the thickness of lines in a legend. By utilizing these techniques, we can create visually appealing and informative plots that help convey the story our data is trying to tell.

Understanding how to adjust the line thickness in Matplotlib can be incredibly useful for data scientists, analysts, and researchers, as it can help to highlight important trends and patterns in data.

## 5) Additional Resources

Matplotlib is a powerful visualization library that offers users a wide range of customization features to create beautiful and informative plots. We have explored some of the techniques used to adjusting line thickness in Matplotlib plots, but there is always more to learn.

In this section, we will provide some additional resources and links to learn more about adjusting line thickness in Matplotlib plots. 1.

## Matplotlib Documentation

The official Matplotlib documentation is a great resource for learning about all the available line properties for creating plots. The documentation provides in-depth explanations of the various line properties, including linewidth, linestyle, and marker size.

The documentation also provides examples of how to use these properties to create various types of plots, making it an excellent resource for those just starting with Matplotlib.

2.

## DataCamp Matplotlib Tutorial

DataCamp offers an extensive tutorial on Matplotlib, which includes sections on adjusting line properties such as thickness, style, and markers. The tutorial covers the basics of Matplotlib, including how to plot line charts, bar charts, and scatterplots.

It then moves on to more advanced topics, such as subplotting and customizing plot aesthetics.

3.

## Matplotlib Cheat Sheets

Cheat sheets are an excellent resource for anyone looking for a quick reference guide on a particular topic. The Matplotlib cheat sheet provides a quick reference for commonly used commands, including how to adjust line thickness.

The cheat sheet also includes examples of how to use various commands to create different types of plots.

4.

## Real Python Matplotlib Tutorial

Real Python provides an in-depth tutorial on Matplotlib that covers many advanced topics, including how to adjust line thickness. The tutorial provides a step-by-step guide to creating various types of plots, including line charts, scatter plots, and bar charts.

It also includes examples of how to use customization tools such as linewidth, linestyle, and marker size to enhance plot aesthetics. 5.

## YouTube Tutorials

YouTube is another excellent resource for learning about Matplotlib. There are several channels dedicated to teaching users how to use Matplotlib to create various types of plots.

Many of these channels offer tutorials on how to adjust line thickness, and their visual format can sometimes make it easier to understand how to use certain commands compared to text-based resources.

## Conclusion

Adjusting line thickness is a fundamental part of creating beautiful and informative plots in Matplotlib. The techniques we have explored can help users bring out important trends and patterns in their data by adjusting line thickness in multiple ways.

By using the resources and links provided, users can delve even deeper into Matplotlib and learn about all the available line properties and commands to create even more customized plots. In conclusion, adjusting line thickness in Matplotlib plots is an essential aspect of creating visually appealing and informative charts.

By using linewidth function, changing default line width, creating a line chart with custom line width, adjusting thickness of multiple lines, and adjusting line thickness in legends, users can create customized plots that highlight important trends and patterns in their data. Additional resources such as the Matplotlib documentation, tutorials, cheat sheets, and YouTube videos are also available to help users learn more about adjusting line thickness and other customization features in Matplotlib.

With this knowledge, data scientists, analysts, and researchers can create powerful and impactful visualizations that effectively communicate their findings to others.