Note
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Facet Grid Plot¶
What it's for: A Facet Grid allows you to create a matrix of subplots (facets) based on categorical variables in your dataset. It is a powerful way to visualize the same relationship across different subsets of data.
When to use: Use this to explore how a relationship (e.g., between model and observation) changes across different sites, months, variables, or experiment groups. It enables "small multiple" visualizations that are much easier to compare than separate plots.
How to read: * Columns/Rows: Represent different levels of a categorical variable (e.g., each column is a different city). * Subplots: Each facet contains a plot of the same type (e.g., a scatter plot). * Interpretation: Compare the trends, slopes, or distributions across the facets to identify inconsistencies or regional/temporal differences.
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
from monet_plots.plots.facet_grid import FacetGridPlot
# 1. Prepare sample data
np.random.seed(42) # for reproducibility
n_samples_per_category = 100
categories = ["Group A", "Group B", "Group C"]
data_list = []
for i, cat in enumerate(categories):
x = np.random.normal(loc=i * 5, scale=2, size=n_samples_per_category)
y = 0.5 * x + np.random.normal(loc=0, scale=1, size=n_samples_per_category) + i * 3
temp_df = pd.DataFrame({"x_data": x, "y_data": y, "category": cat})
data_list.append(temp_df)
df = pd.concat(data_list).reset_index(drop=True)
# 2. Initialize FacetGridPlot
# We'll create a column for each 'category'
fg_plot = FacetGridPlot(data=df, col="category", height=4, aspect=1.2)
# 3. Map a scatter plot to each facet
fg_plot.grid.map(plt.scatter, "x_data", "y_data", alpha=0.7, s=50, edgecolor="w")
# 4. Set titles and labels
fg_plot.set_titles(col_template="Category: {col_name}")
fg_plot.grid.set_xlabels("X-axis Data")
fg_plot.grid.set_ylabels("Y-axis Data")
fg_plot.fig.suptitle(
"Scatter Plot across Categories", y=1.02
) # y adjusts title position
plt.tight_layout()
plt.show()
Total running time of the script: ( 0 minutes 0.662 seconds)
Download Python source code: plot_facet_grid.py