Matplotlib Notes

Originally written on 2020-01-20. DEV's displayed publication date reflects this archive migration.

installation

$ python3 -m pip install --user matplotlib

notes

plotting a simple line graph is actually quite easy employing matplotlib. After installation,

1. import matplotlib.pyplot as plt (pyplot module provides many functions that generate charts and plots);

2. declare input and output values (on x and y axis);

3. Before generate the plot, you can choose a built-in style for the plot: plt.style.use('xxxx')
   

   >>> plt.style.available
   ['seaborn-dark', 'seaborn-darkgrid', 'seaborn-ticks', 'fivethirtyeight', 'seaborn-whitegrid', 'classic', '_classic_test', 'fast', 'seaborn-talk', 'seaborn-dark-palette', 'seaborn-bright', 'seaborn-pastel', 'grayscale', 'seaborn-notebook', 'ggplot', 'seaborn-colorblind', 'seaborn-muted', 'seaborn', 'Solarize_Light2', 'seaborn-paper', 'bmh', 'tableau-colorblind10', 'seaborn-white', 'dark_background', 'seaborn-poster', 'seaborn-deep']

1. fig, ax = plt.subplots() (subplots function can generate one or more plots in the same figure, fig->the_whole_figure, ax->a_plot_in_figure);

2. ax.axis([x_from, x_to, y_from, y_to]) setting axis range

3. Methods to render data:

   1. Plot a single line: ax.plot(input, output, lineweight=x)
   2. Plot dots: ax.scatter(x, y, s=number, c='color_name'/(0.3, 0.8, 1))

4. style the plot i.e. the ax, by setting its title and x/y labels, tick_params
   

ax.set_title("Square Numbers", fontsize=24)
ax.set_xlabel("Value", fontsize=14)
ax.set_ylabel("Square of Value", fontsize=14)
ax.tick_params(axis='both', labelsize=14)

1. plt.show() (opens matplotlib's viewer)