# ======================================================================================
# Copyright (©) 2014-2026 Laboratoire Catalyse et Spectrochimie (LCS), Caen, France.
# CeCILL-B FREE SOFTWARE LICENSE AGREEMENT
# See full LICENSE agreement in the root directory.
# ======================================================================================
# ruff: noqa
"""
Introduction to the plotting library
====================================

This short gallery example shows three common ideas:

- the default ``dataset.plot()`` entry point;
- per-call style changes that do not mutate later plots;
- ``plot_multiple()`` overlaying several 1D datasets on one shared axes.
"""

# %%

import os
from pathlib import Path

import numpy as np
import spectrochempy as scp

# %%
# Locate and load a dataset
# --------------------------
datadir = scp.preferences.datadir
TEST_FILE = Path(
    os.environ.get("TEST_FILE", datadir / "irdata" / "nh4y-activation.spg")
)
dataset = scp.read(TEST_FILE)

# %%
# Default plot and style
# -----------------------
ax = dataset[0].plot()

# %%
# Per-call style changes
# -----------------------
# Apply a style to this single plot only:
ax = dataset[0].plot(style="classic")

# %%
# The style change is local — the default style is used again here:
ax = dataset[0].plot()

# %%
# Overlay with ``plot_multiple``
# -------------------------------
dataset = dataset[:, ::100]

sample_indices = np.linspace(0, dataset.shape[0] - 1, 5, dtype=int)
datasets = [dataset[index] for index in sample_indices]
labels = [f"sample {index}" for index in sample_indices]

_ = scp.plot_multiple(method="scatter", datasets=datasets, labels=labels, legend="best")

# %%
# The style change applies only to this call:
_ = scp.plot_multiple(
    method="scatter", style="sans", datasets=datasets, labels=labels, legend="best"
)

# %%
# The default style is used again on the next call:
_ = scp.plot_multiple(method="scatter", datasets=datasets, labels=labels, legend="best")

# %%
# This ends the example ! The following line can be uncommented if no plot shows when
# running the .py script with python

# scp.show()