[파이썬] matplotlib 색상 및 스타일 설정

Matplotlib is a popular data visualization library in Python. It offers a wide range of customization options for colors and styles to make your plots visually appealing. In this blog post, we will explore how to set colors and styles in Matplotlib.

Setting Colors

Matplotlib allows you to specify colors for various elements of your plot, such as lines, markers, and text. You can specify colors using different formats, including named colors, RGB or RGBA values, hexadecimal codes, or a predefined color map.

Named Colors

Matplotlib provides a set of predefined named colors that can be used to specify colors. Some common named colors include “red”, “blue”, “green”, “yellow”, and “purple”. You can simply pass the name of the color when setting the color of an element in your plot.

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16], color='red')
plt.show()

RGB or RGBA Values

You can also specify colors using RGB or RGBA values. RGB values range from 0 to 1, where 0 represents no intensity and 1 represents full intensity. RGBA values include an additional alpha channel, which controls the transparency of the color.

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16], color=(0.2, 0.4, 0.6))  # RGB values
plt.plot([1, 2, 3, 4], [1, 4, 9, 16], color=(0.2, 0.4, 0.6, 0.5))  # RGBA values
plt.show()

Hexadecimal Codes

Another way to specify colors is by using hexadecimal codes. Hexadecimal codes consist of a pound sign (#) followed by six hexadecimal digits, representing the intensity of red, green, and blue channels.

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16], color='#FF0000')  # Red color
plt.show()

Predefined Color Maps

Matplotlib provides a variety of predefined color maps that can be used to map data values to colors. These color maps are useful for visualizing data where the color represents a specific value. You can use the cmap parameter to specify a color map.

import matplotlib.pyplot as plt

x = [1, 2, 3, 4]
y = [1, 4, 9, 16]
colors = [0.0, 0.25, 0.5, 0.75]  # Data values
plt.scatter(x, y, c=colors, cmap='cool')
plt.colorbar(label='Data Values')
plt.show()

Setting Styles

Matplotlib allows you to customize the style of your plots, including line styles, marker styles, and font styles. You can use various properties and parameters to achieve the desired style.

Line Styles

You can modify the line style of a plot using the linestyle parameter. Some available line styles include solid (‘-‘), dashed (‘–’), dotted (‘:’), and dash-dot (‘-.’).

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16], linestyle='--')
plt.show()

Marker Styles

Markers are used to highlight individual data points in a plot. Matplotlib provides a wide range of marker styles, such as circles (‘o’), squares (‘s’), triangles (‘^’), and more. You can set the marker style using the marker parameter.

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16], marker='o')
plt.show()

Font Styles

You can customize the font style of text elements in your plot, including the title, labels, and legends. Matplotlib provides properties such as fontsize, fontweight, and fontstyle to change the appearance of the text.

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4], [1, 4, 9, 16])
plt.title('Sample Plot', fontsize=14, fontweight='bold')
plt.xlabel('X-axis', fontsize=12, fontstyle='italic')
plt.ylabel('Y-axis', fontsize=12)
plt.show()

By using various color and style options, you can create visually appealing plots that effectively communicate your data. Experiment with different combinations to find the style that best suits your needs.

That’s all for this blog post on matplotlib color and style customization. Happy plotting!