Line charts

Matplotlib Basics

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A line chart connects data points with straight lines, typically used to show trends over time or continuous relationships between variables.

Syntax:

plt.plot(x, y, fmt, **kwargs)

Parameters:

x = sequence of x-values
y = sequence of y-values
fmt (optional) = a shorthand string that defines:
- line style (-, --, -., :)
- marker (o, s, ^, etc.)
- colour (r, g, b, etc.)

Example:
plt.plot(x, y, 'ro--') means:
r = red, o = circle marker, -- = dashed line

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]

y = [2, 3, 5, 7, 11]

plt.plot(x, y)

plt.title("Basic Line Chart")

plt.xlabel("X Axis")

plt.ylabel("Y Axis")

plt.show()

Optional shorthand way of formatting the line and markers.

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]

y = [2, 3, 5, 7, 11]

plt.plot(x, y, 'r--o')

plt.show()

Shorthand options:

Alternative way of styling the line and markers, with parameters for each format choice.

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]

y = [2, 3, 5, 7, 11]

plt.plot(x, y, color='magenta', linestyle='-', linewidth=2, marker='^', markersize=8)

plt.title("Customised Line Chart")

plt.show()

Styling parameters:

Parameter	Description	Example
`color`	Line colour	`'red'`, `'#00FF00'`, `(0.1, 0.2, 0.5)`
`linestyle`	Style of the line	`'-', '--', '-.', ':'`
`linewidth`	Thickness of the line	`linewidth=2`
`marker`	Symbol for data points	`'o', 's', '^', '*'`
`markersize`	Size of the markers	`markersize=10`
`markerfacecolor`, `markeredgecolor`	Marker fill & border colours	`'red'`, `'#00FF00'`, `(0.1, 0.2, 0.5)`